Air safety
Encyclopedia
Air safety is a term encompassing the theory, investigation and categorization of flight failures
, and the prevention of such failures through regulation, education and training. It can also be applied in the context of campaigns that inform the public as to the safety of air travel
.
. Of particular significance was the Air Commerce Act 1926
, which required pilots and aircraft to be examined and licensed, for accidents to be properly investigated, and for the establishment of safety rules and navigation aids, under the Aeronautics Branch of the Department of Commerce
.
Despite this, in 1926 and 1927 there were a total of 24 fatal commercial airline crashes, a further 16 in 1928, and 51 in 1929 (killing 61 people), which remains the worst year on record at an accident rate of about 1 for every 1000000 miles (1,609,340 km) flown. Based on the current numbers flying, this would equate to 7,000 fatal incidents per year.
The fatal incident rate has declined steadily ever since, and, since 1997 the number of fatal air accidents has been no more than 1 for every 2,000,000,000 person-miles flown (e.g., 100 people flying a plane for 1000 miles (1,609.3 km) counts as 100,000 person-miles, making it comparable with methods of transportation with different numbers of passengers, such as one person driving a car
for 100000 miles (160,934 km), which is also 100,000 person-miles), making it one of the safest modes of transportation, if measured by distance traveled.
A disproportionate number of all U.S. aircraft crashes occur in Alaska
, largely as a result of severe weather conditions. Between 1990-2006 there were 1441 commuter and air taxi
crashes in the U.S. of which 373 (26%) were fatal, resulting in 1063 deaths (142 occupational pilot deaths). Alaska accounted for 513 (36%) of the total U.S. crashes.
Another aspect of safety is protection from attack currently known as Security (as the ISO definition of safety encompasses non-intentional (safety_safety) and intentional (safety_security) causes of harm or property
damage
). The terrorist attacks
of 2001 are not counted as accidents. However, even if they were counted as accidents they would have added only about 2 deaths per 2,000,000,000 person-miles. Only 2 months later, American Airlines Flight 587
crashed in Queens
, NY
, killing 256 people, including 5 on the ground, causing 2001 to show a very high fatality rate. Even so, the rate that year including the attacks (estimated here to be about 4 deaths per 1,000,000,000 person-miles), is safe compared to some other forms of transport, if measured by distance traveled.
Safety improvements have resulted from improved aircraft design
, engineering and maintenance, the evolution of navigation aids, and safety protocols and procedures.
It is often reported that air travel is the safest in terms of deaths per passenger mile. The National Transportation Safety Board
(2006) reports 1.3 deaths per hundred million vehicle miles for travel by car, and 1.7 deaths per hundred million vehicle miles for travel by air. These are not passenger miles. If an airplane has 100 passengers, then the passenger miles are 100 times higher. The number of deaths per passenger mile on commercial airlines in the United States between 1995 and 2000 is about 3 deaths per 10 billion passenger miles.
was developed from this in the 1930s, indicating to the pilot the angle of descent to the airfield. This later became adopted internationally through the standards of the International Civil Aviation Organization
(ICAO).
In 1929 Jimmy Doolittle developed instrument flight
.
With the spread of radio
technology, several experimental radio based navigation aids
were developed from the late 1920s onwards. These were most successfully used in conjunction with instruments
in the cockpit
in the form of Instrument landing system
s (ILS), first used by a scheduled flight to make a landing in a snowstorm at Pittsburgh
in 1938. A form of ILS was adopted by the ICAO for international use in 1949.
Following the development of radar
in World War II
, it was deployed as a landing aid for civil aviation in the form of Ground-controlled approach
(GCA
) systems, joined in 1948 by distance measuring equipment
(DME), and in the 1950s by airport surveillance radar
as an aid to air traffic control
. VHF omnidirectional range
(VOR) stations became the predominate means of route navigation during the 1960s, superseding the low frequency radio ranges and the Non-directional beacon
(NDB). The ground based VOR stations were often co-located with DME transmitters and then labeled as VOR-DME stations on navigation charts. VORTAC stations, which combined VOR and TACAN features (military TACtical Air Navigation) — the latter including both a DME distance feature and a separate TACAN azimuth feature, which provides military pilots data similar to the civilian VOR, were also used in that new system. With the proper receiving equipment in the aircraft, pilots could know their radials in degrees to/from the VOR station, as well as the slant range distance to/from, if the station was co-located with DME or TACAN.
All of the ground-based navigation aids are being supplemented by satellite
-based aids like Global Positioning System
(GPS), which make it possible for aircrews to know their position with great precision anywhere in the world. With the arrival of Wide Area Augmentation System
(WAAS), GPS navigation has become accurate enough for vertical (altitude) as well as horizontal use, and is being used increasingly for
instrument approaches as well as en-route navigation. However, since the GPS constellation is a single point of failure
that can be switched off by the U.S. military
in time of crisis, onboard Inertial Navigation System
(INS) or ground-based navigation aids are still required for backup.
crashed after hitting a part that had fallen from another aircraft.
on average of twice per year. While the "flash and bang" is startling to the passengers and crew, aircraft are able to withstand normal lightning strikes.
The dangers of more powerful positive lightning were not understood until the destruction of a glider
in 1999. It has since been suggested that positive lightning may have caused the crash of Pan Am
Flight 214
in 1963. At that time aircraft were not designed to withstand such strikes, since their existence was unknown at the time standards were set. The 1985 standard in force at the time of the glider crash, Advisory Circular AC 20-53A, was replaced by Advisory Circular AC 20-53B in 2006, however it is unclear whether adequate protection against positive lightning was incorporated.
The effects of normal lightning on traditional metal-covered aircraft are well understood and serious damage from a lightning strike on an airplane is rare. However, as more and more aircraft, like the upcoming Boeing 787
, whose whole exterior is made of non-conducting composite material
s take to the skies, additional design effort and testing must be made before certification authorities will permit these aircraft in commercial service.
can be factors in airline accidents. In 2005, Southwest Airlines Flight 1248
slid off the end of a runway
after landing in heavy snow conditions, killing one child.
Even a small amount of icing
or coarse frost
can greatly impair the ability of a wing to develop adequate lift
, which is why regulations prohibit ice, snow or even frost on the wings or tail, prior to takeoff. Air Florida Flight 90
crashed on takeoff in 1982, as a result of ice/snow on its wings.
An accumulation of ice during flight can be catastrophic, as evidenced by the loss of control and subsequent crashes of American Eagle
Flight 4184
in 1994, and Comair Flight 3272
in 1997. Both aircraft were turboprop
airliners, with straight wings, which tend to be more susceptible to inflight ice accumulation, than are swept-wing jet airliners.
Airlines and airports ensure that aircraft are properly de-iced
before takeoff
whenever the weather involves icing conditions
. Modern airliners are designed to prevent ice buildup on wing
s, engines
, and tails (empennage
) by either routing heated air from jet engine
s through the leading edge
s of the wing, and inlets, or on slower aircraft, by use of inflatable rubber "boots
" that expand to break off any accumulated ice.
Airline flight plans require airline dispatch offices to monitor the progress of weather along the routes of their flights, helping the pilots
to avoid the worst of inflight icing conditions. Aircraft can also be equipped with an ice detector
in order to warn pilots to leave unexpected ice accumulation areas, before the situation becomes critical.
(e.g. British Airways Flight 38
), fuel exhaustion (e.g. Gimli Glider
), foreign object damage
(e.g. US Airways Flight 1549
), mechanical failure due to metal fatigue
(e.g. Kegworth air disaster
, El Al Flight 1862
, China Airlines Flight 358
), mechanical failure due to improper maintenance (e.g. American Airlines Flight 191
), mechanical failure caused by an original manufacturing defect in the engine (e.g. Qantas Flight 32
, United Airlines Flight 232
, Delta Air Lines Flight 1288
), and pilot error (e.g. Pinnacle Airlines Flight 3701
).
In a multi-engine aircraft, failure of a single engine usually results in a precautionary landing being performed, for example landing at a diversion airport
instead of continuing to the intended destination. Failure of a second engine (e.g. Dominicana DC-9 air disaster
) or damage to other aircraft systems caused by an uncontained engine failure (e.g. United Airlines Flight 232
) may, if an emergency landing
is not possible, result in the aircraft crashing.
include the De Havilland Comet
accidents (1950s) and Aloha Airlines Flight 243
(1988). Now that the subject is better understood, rigorous inspection and nondestructive testing
procedures are in place.
Composite material
s consist of layers of fiber
s embedded in a resin
matrix. In some cases, especially when subjected to cyclic stress
, the layers of the material separate from each other (delaminate
) and lose strength. As the failure develops inside the material, nothing is shown on the surface; instrument methods (often ultrasound
-based) have to be used to detect such a material failure. In the 1940s several Yakovlev Yak-9
s experienced delamination of plywood
in their construction.
ing an aircraft (increasing the angle of attack
to a point at which the wings fail to produce enough lift
), is dangerous and can result in a crash if the pilot fails to quickly react in the proper manner. The only way to recover with a minimum loss of altitude, is to lower the nose (reduces the angle of attack of the wings, so that the boundary layer
re-attaches to the wing), while commanding maximum power from the engines. If the pilot delays initiating that kind of response, a crash is inevitable if the plane is not high enough above all terrain, when the stall occurs.
Devices have been developed to warn the pilot when the plane's speed is coming close to the stall speed. These include stall warning horns (now standard on virtually all powered aircraft), stick shaker
s and voice warnings. Most stalls are a result of the pilot allowing the plane to go too slow for the particular weight and configuration at the time. The stall speed is higher on virtually all aircraft, if ice or even frost has attached to the wings and/or horizontal tail stabilizer. The more severe the icing, the higher will be the stall speed, not only because smooth airflow over the wings becomes increasingly more difficult, but also because of the added weight of the accumulated ice.
"High speed stalls" are also possible, if a pilot tries to pull out of a dive so quickly that he increases the angle of attack to the point of boundary layer separation of the airflow over the wings. Again, the only solution is to lower the nose somewhat, even though the plane is already diving at high speed, and then to resume the pull-out with a less severe angle of attack.
Crashes, caused by a full stall of the airfoils include:
Safety regulations control aircraft materials and the requirements for automated fire safety systems. Usually these requirements take the form of required tests. The tests measure flammability and the toxicity
of smoke
. When the tests fail, they fail on a prototype in an engineering laboratory, rather than in an aircraft.
Fire on board the aircraft, and more especially the toxic smoke generated, have been the cause of accidents. An electrical fire on Air Canada Flight 797
in 1983 caused the deaths of 23 of the 46 passengers, resulting in the introduction of floor level lighting to assist people to evacuate a smoke-filled aircraft. Two years later a fire on the runway caused the loss of 55 lives, 48 from the effects of incapacitating and subsequently lethal toxic gas and smoke, in the 1985 British Airtours
Flight 28M
. That accident raised serious concerns relating to survivability, something that prior to 1985 had not been studied in such detail. The swift incursion of the fire into the fuselage and the layout of the aircraft impaired passengers' ability to evacuate, with areas such as the forward galley area becoming a bottle-neck for escaping passengers, with some dying very close to the exits. A large amount of research into evacuation and cabin and seating layouts was carried at Cranfield Institute
to try to measure what makes a good evacuation route, which led to the seat layout by Overwing exits
being changed by mandate and the examination of evacuation requirements relating to the design of galley areas. The use of smoke hood
s or misting systems were also examined although both were rejected.
South African Airways Flight 295
was lost in the Indian Ocean in 1987 after an in-flight fire in the cargo hold could not be suppressed by the crew. The cargo holds of most airliners are now equipped with automated halon
fire extinguishing
systems to combat a fire that might occur in the baggage holds. In May 1996 ValuJet Airlines
Flight 592
crashed into the Florida
Everglades
a few minutes after takeoff after a fire broke out in the forward cargo hold. All 110 aboard were killed.
At one time fire fighting
foam path
s were laid down before an emergency landing, but the practice was considered only marginally effective, and concerns about the depletion of fire fighting capability due to pre-foaming led the United States FAA to withdraw its recommendation in 1987.
One possible cause of fires in airplanes are wiring problems that involve intermittent faults, such as wires with breached insulation touching each other, having water dripping on them, or short circuits. These are difficult to detect once the plane is on the ground. However, there are methods, such as spread-spectrum time-domain reflectometry
, that can feasibly test live wires on aircraft during flight.
Modern jet engines have the capability of surviving an ingestion of a bird. Small fast planes, such as military jet fighters
, are at higher risk than heavy multi-engine ones. This is due to the fact that the fan of a high-bypass turbofan
engine, typical on transport aircraft, acts as a centrifugal separator to force ingested materials (birds, ice, etc.) to the outside of the fan's disc. As a result, such materials go through the relatively unobstructed bypass duct
, rather than through the core of the engine, which contains the smaller and more delicate compressor blades. Military aircraft
designed for high-speed flight typically have pure turbojet, or low-bypass turbofan engines, increasing the risk that ingested materials will get into the core of the engine to cause damage.
The highest risk of the bird strike is during the takeoff and landing
, in low altitude
s, which is in the vicinity of the airport
s. Some airports use active countermeasures, ranging from a person with a shotgun
through recorded sounds of predators to employing falconer
s. Poisonous grass can be planted that is not palatable to birds, nor to insects that attract insectivorous
birds. Passive countermeasures involve sensible land-use management, avoiding conditions attracting flocks of birds to the area (e.g. landfill
s). Another tactic found effective is to let the grass at the airfield grow taller (approximately 12 inches (30.5 cm)) as some species of birds won't land if they cannot see one another.
at the airport. In the act of servicing the aircraft between flights a great deal of ground equipment must operate in close proximity to the fuselage and wings. Occasionally the aircraft gets bumped or worse.
Damage may be in the form of simple scratches in the paint or small dents in the skin. However, because aircraft structures (including the outer skin) play such a critical role in the safe operation of a flight, all damage is inspected, measured and possibly tested to ensure that any damage is within safe tolerances.
An example of this problem was the depressurization incident on Alaska Airlines
Flight 536 in 2005. During ground services a baggage handler
hit the side of the aircraft with a tug towing a train of baggage cart
s. This damaged the metal skin of the aircraft. This damage was not reported and the plane departed. Climbing through 26000 feet (7,924.8 m) the damaged section of the skin gave way due to the growing difference in pressure between the inside of the aircraft and the outside air. The cabin depressurized
with a bang necessitating a rapid descent back to denser (breathable) air and an emergency landing. Post landing examination of the fuselage revealed a 12 in (30.5 cm) hole on the right side of the airplane.
near active volcano
es can damage propeller
s, engines
and cockpit windows.
In 1982, British Airways Flight 9
flew through an ash cloud and temporarily lost power from all four engines.
Prior to 2010 the general approach taken by airspace regulators was that if the ash concentration rose above zero, then the airspace was considered unsafe and was consequently closed.
Volcanic Ash Advisory Center
s enable liaison between meteorologist
s, volcanologist
s, and the aviation industry.
Human factors
including pilot error
are another potential danger, and currently the most common factor of aviation crashes. Much progress in applying human factors to improving aviation safety was made around the time of World War II
by people such as Paul Fitts
and Alphonse Chapanis
. However, there has been progress in safety throughout the history of aviation, such as the development of the pilot's checklist
in 1937. Pilot error and improper communication are often factors in the collision
of aircraft. This can take place in the air
(1978 Pacific Southwest Airlines
Flight 182
) (TCAS) or on the ground (1977 Tenerife disaster
) (RAAS
). The ability of the flight crew to maintain situational awareness is a critical human factor in air safety. Human factors training is available to general aviation pilots and called single pilot resource management training.
Failure of the pilots to properly monitor the flight instruments resulted in the crash of Eastern Air Lines
Flight 401
in 1972 controlled flight into terrain
(CFIT), and error during take-off and landing can have catastrophic consequences, for example cause the crash of Prinair
Flight 191
on landing, also in 1972.
Rarely, flight crew members are arrested or subject to disciplinary action for being intoxicated
on the job. In 1990, three Northwest Airlines
crew members were sentenced to jail for flying to Minneapolis
while drunk. In 2001, Northwest fired a pilot who failed a breathalyzer
test after a flight. In July 2002, two America West Airlines
pilots were arrested just before they were scheduled to fly because they had been drinking alcohol
. The pilots have been fired from America West and the FAA revoked their pilot's licenses. As of 2005 they await trial in a Florida court. The incident created a public relations problem and America West has become the object of many jokes about drunk pilots. At least one fatal airliner accident involving drunk pilots has occurred when Aero Flight 311
crashed killing all 25 on board in 1961, which underscores the role that poor human choices can play in air accidents.
Human factors incidents are not limited to errors by the pilots. The failure to close a cargo door properly on Turkish Airlines
Flight 981
in 1974 resulted in the loss of the aircraft - however the design of the cargo door latch was also a major factor in the accident. In the case of Japan Airlines Flight 123
, improper maintenance led to explosive decompression of the cabin, which in turn destroyed the vertical stabilizer
and the integrity of all four hydraulic systems, which powered all the flight controls.
s can also cause CFIT accidents. One of the most notable CFIT accidents was in December 1995 in which American Airlines flight 965
tracked off course while approaching Calí, Colombia and hit a mountainside despite a ground proximity warning system
terrain warning in the cockpit and desperate pilot attempt to gain altitude after that warning. Crew position awareness and monitoring of navigational systems are essential to the prevention of CFIT accidents. As of February, 2008, over 40,000 aircraft had the Enhanced version of the GPWS system installed, and they had flown over 800 million hours without a single CFIT accident.
Another anti-CFIT tool is the Minumum Safe Altitude Warning (MSAW) system avaiable near many airports. It monitors the altitudes transmitted by aircraft transponders and compares that with the system's defined minimum safe altitudes for a given area. When the system determines the aircraft is lower, or will soon be lower, than the minimum safe altitude (MSA), the air traffic controller receives an acoustic and visual warning and then alerts the pilot that his aircraft is too low.
deviations. Use of personal electronic devices and calculator
s may be prohibited when an aircraft is below 10,000', taking off, or landing. The American Federal Communications Commission
(FCC) prohibits the use of a cell phone
on most flights, because in-flight usage creates problems with ground-based cells. There is also concern about possible interference with aircraft navigation systems, although that has never been proven to be a non-serious risk on airliners. A few flights now allow use of cell phones, where the aircraft have been specially wired and certified to meet both FAA and FCC regulations.
situations. Since the September 11, 2001 attacks
, stricter airport
and airline security
measures are in place to prevent terrorism
.
, it appears that the first officer deliberately dived his aircraft into the Atlantic Ocean
while the captain was away from his station, in 1999 off Nantucket, Massachusetts
. Motivations are unclear, but recorded inputs from the black boxes
showed no mechanical problem, no other aircraft in the area, and was corroborated by the cockpit voice recorder
.
In 1982, Japan Airlines Flight 350
crashed while on approach to the Tokyo Haneda Airport, killing 24 of the 174 onboard. The official investigation found the mentally ill captain had attempted suicide by placing the inboard engines into reverse thrust, while the plane was close to the runway. The first officer did not have enough time to countermand his actions, before the plane stalled and crashed.
In 1997, SilkAir Flight 185
suddenly went into a high dive from its cruising altitude. The speed of the dive was so high that the plane began to break apart before it finally crashed near Palembang
, Sumatra
. After three years of investigation, the Indonesian autorities declared that the cause of the accident can not be determined. However, the US NTSB concluded that deliberate suicide by the Captain, was the only reasonable explanation for the cause of that crash.
, usually extending 500 feet (152.4 m) to each side and 1000 feet (304.8 m) beyond the end of a runway. This is intended to cover ninety percent of the cases of an aircraft leaving the runway by providing a buffer space free of obstacles. Since this is a recent rule, many airports do not meet it. One method of substituting for the 1000 feet (304.8 m) at the end of a runway for airports in congested areas is to install an Engineered materials arrestor system
, or EMAS. These systems are usually made of a lightweight, crushable concrete that absorbs the energy of the aircraft to bring it to a rapid stop. They have stopped three aircraft (as of 2005) at JFK Airport
.
According to a 2000 report by the National Transportation Safety Board
, emergency aircraft evacuation
s happen about once every 11 days in the U.S. While some situations are extremely dire, such as when the plane is on fire, in many cases the greatest challenge for passengers can be the use of the airplane slide
. In a TIME article on the subject, Amanda Ripley reported that when a new supersized Airbus A380 underwent mandatory evacuation tests in 2006, 33 of the 873 evacuating volunteers got hurt. While the evacuation was generally considered a success, one volunteer suffered a broken leg, while the remaining 32 received slide burns. Such accidents are common. In her article, Ripley provides tips on how to make it down the airplane slide without injury.
It is necessary to mention that first two statistics are computed for typical travels for respective forms of transport, so they cannot be used directly to compare risks related to different forms of transport in a particular travel "from A to B". For example: according to statistics, a typical flight from Los Angeles to New York will carry a larger risk factor than a typical car travel from home to office. But a car travel from Los Angeles to New York would not be typical. It would be as large as several dozens of typical car travels, and associated risk will be larger as well. Because the journey would take a much longer time, the overall risk associated by making this journey by car will be higher than making the same journey by air, even if each individual hour of car travel can be less risky than an hour of flight. In the same vein, when considering the "deaths per billion passenger journeys" statistic, it is important to consider that airliners, buses and trains will carry far more passengers than a car, or bicycle for example.
It is therefore important to use each statistic in a proper context. When it comes to a question about risks associated with a particular long-range travel from one city to another, the most suitable statistic is the third one, thus giving a reason to name air travel as the safest form of long-range transportation.
It is worth noting that the air industry's insurers base their calculations on the number of deaths per passenger-journey statistic while the industry itself generally uses the number of deaths per passenger-kilometre statistic in press releases.
The major Safety initiatives worldwide are:
Aviation accidents and incidents
An aviation accident is defined in the Convention on International Civil Aviation Annex 13 as an occurrence associated with the operation of an aircraft which takes place between the time any person boards the aircraft with the intention of flight and all such persons have disembarked, in which a...
, and the prevention of such failures through regulation, education and training. It can also be applied in the context of campaigns that inform the public as to the safety of air travel
Air travel
Air travel is a form of travel in vehicles such as airplanes, helicopters, hot air balloons, blimps, gliders, hang gliding, parachuting or anything else that can sustain flight.-Domestic and international flights:...
.
United States
During the 1920s, the first laws were passed in the USA to regulate civil aviationCivil aviation
Civil aviation is one of two major categories of flying, representing all non-military aviation, both private and commercial. Most of the countries in the world are members of the International Civil Aviation Organization and work together to establish common standards and recommended practices...
. Of particular significance was the Air Commerce Act 1926
United States government role in civil aviation
Governments have played an important part in shaping air transportation. This role began as early as 1783, when the king of France summoned the Montgolfier brothers to demonstrate their balloon. In 1892, the French War Ministry backed an attempt to build a heavier-than-air flying machine...
, which required pilots and aircraft to be examined and licensed, for accidents to be properly investigated, and for the establishment of safety rules and navigation aids, under the Aeronautics Branch of the Department of Commerce
United States Department of Commerce
The United States Department of Commerce is the Cabinet department of the United States government concerned with promoting economic growth. It was originally created as the United States Department of Commerce and Labor on February 14, 1903...
.
Despite this, in 1926 and 1927 there were a total of 24 fatal commercial airline crashes, a further 16 in 1928, and 51 in 1929 (killing 61 people), which remains the worst year on record at an accident rate of about 1 for every 1000000 miles (1,609,340 km) flown. Based on the current numbers flying, this would equate to 7,000 fatal incidents per year.
The fatal incident rate has declined steadily ever since, and, since 1997 the number of fatal air accidents has been no more than 1 for every 2,000,000,000 person-miles flown (e.g., 100 people flying a plane for 1000 miles (1,609.3 km) counts as 100,000 person-miles, making it comparable with methods of transportation with different numbers of passengers, such as one person driving a car
Automobile
An automobile, autocar, motor car or car is a wheeled motor vehicle used for transporting passengers, which also carries its own engine or motor...
for 100000 miles (160,934 km), which is also 100,000 person-miles), making it one of the safest modes of transportation, if measured by distance traveled.
A disproportionate number of all U.S. aircraft crashes occur in Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
, largely as a result of severe weather conditions. Between 1990-2006 there were 1441 commuter and air taxi
Air taxi
An air taxi is an air charter passenger or cargo aircraft which operates on an on-demand basis.-Regulation:In the United States, air taxi and air charter operations are governed by Part 135 of the Federal Aviation Regulations , unlike the larger scheduled air carriers which are governed by more...
crashes in the U.S. of which 373 (26%) were fatal, resulting in 1063 deaths (142 occupational pilot deaths). Alaska accounted for 513 (36%) of the total U.S. crashes.
Another aspect of safety is protection from attack currently known as Security (as the ISO definition of safety encompasses non-intentional (safety_safety) and intentional (safety_security) causes of harm or property
Property
Property is any physical or intangible entity that is owned by a person or jointly by a group of people or a legal entity like a corporation...
damage
Property damage
Property damage is damage to or the destruction of public or private property, caused either by a person who is not its owner or by natural phenomena. Property damage caused by persons is generally categorized by its cause: neglect , and intentional damage...
). The terrorist attacks
September 11, 2001 attacks
The September 11 attacks The September 11 attacks The September 11 attacks (also referred to as September 11, September 11th or 9/119/11 is pronounced "nine eleven". The slash is not part of the pronunciation...
of 2001 are not counted as accidents. However, even if they were counted as accidents they would have added only about 2 deaths per 2,000,000,000 person-miles. Only 2 months later, American Airlines Flight 587
American Airlines Flight 587
American Airlines Flight 587, an Airbus A300, crashed into the Belle Harbor neighborhood of Queens, a borough of New York City, New York, shortly after takeoff from John F. Kennedy International Airport on November 12, 2001. This is the second deadliest U.S...
crashed in Queens
Queens
Queens is the easternmost of the five boroughs of New York City. The largest borough in area and the second-largest in population, it is coextensive with Queens County, an administrative division of New York state, in the United States....
, NY
New York City
New York is the most populous city in the United States and the center of the New York Metropolitan Area, one of the most populous metropolitan areas in the world. New York exerts a significant impact upon global commerce, finance, media, art, fashion, research, technology, education, and...
, killing 256 people, including 5 on the ground, causing 2001 to show a very high fatality rate. Even so, the rate that year including the attacks (estimated here to be about 4 deaths per 1,000,000,000 person-miles), is safe compared to some other forms of transport, if measured by distance traveled.
Safety improvements have resulted from improved aircraft design
Aeronautics
Aeronautics is the science involved with the study, design, and manufacturing of airflight-capable machines, or the techniques of operating aircraft and rocketry within the atmosphere...
, engineering and maintenance, the evolution of navigation aids, and safety protocols and procedures.
It is often reported that air travel is the safest in terms of deaths per passenger mile. The National Transportation Safety Board
National Transportation Safety Board
The National Transportation Safety Board is an independent U.S. government investigative agency responsible for civil transportation accident investigation. In this role, the NTSB investigates and reports on aviation accidents and incidents, certain types of highway crashes, ship and marine...
(2006) reports 1.3 deaths per hundred million vehicle miles for travel by car, and 1.7 deaths per hundred million vehicle miles for travel by air. These are not passenger miles. If an airplane has 100 passengers, then the passenger miles are 100 times higher. The number of deaths per passenger mile on commercial airlines in the United States between 1995 and 2000 is about 3 deaths per 10 billion passenger miles.
Navigation aids and instrument flight
One of the first navigation aids to be introduced (in the USA in the late 1920s) was airfield lighting to assist pilots to make landings in poor weather or after dark. The Precision Approach Path IndicatorPrecision Approach Path Indicator
Precision approach path Indicator is a visual aid that provides guidance information to help a pilot acquire and maintain the correct approach to an aerodrome or an airport. It is generally located beside the runway approximately 300 metres beyond the landing threshold of the runway...
was developed from this in the 1930s, indicating to the pilot the angle of descent to the airfield. This later became adopted internationally through the standards of the International Civil Aviation Organization
International Civil Aviation Organization
The International Civil Aviation Organization , pronounced , , is a specialized agency of the United Nations. It codifies the principles and techniques of international air navigation and fosters the planning and development of international air transport to ensure safe and orderly growth...
(ICAO).
In 1929 Jimmy Doolittle developed instrument flight
Flight instruments
Flight instruments are the instruments in the cockpit of an aircraft that provide the pilot with information about the flight situation of that aircraft, such as height, speed and altitude...
.
With the spread of radio
Radio
Radio is the transmission of signals through free space by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space...
technology, several experimental radio based navigation aids
Radio navigation
Radio navigation or radionavigation is the application of radio frequencies to determine a position on the Earth. Like radiolocation, it is a type of radiodetermination.The basic principles are measurements from/to electric beacons, especially...
were developed from the late 1920s onwards. These were most successfully used in conjunction with instruments
Flight instruments
Flight instruments are the instruments in the cockpit of an aircraft that provide the pilot with information about the flight situation of that aircraft, such as height, speed and altitude...
in the cockpit
Cockpit
A cockpit or flight deck is the area, usually near the front of an aircraft, from which a pilot controls the aircraft. Most modern cockpits are enclosed, except on some small aircraft, and cockpits on large airliners are also physically separated from the cabin...
in the form of Instrument landing system
Instrument Landing System
An instrument landing system is a ground-based instrument approach system that provides precision guidance to an aircraft approaching and landing on a runway, using a combination of radio signals and, in many cases, high-intensity lighting arrays to enable a safe landing during instrument...
s (ILS), first used by a scheduled flight to make a landing in a snowstorm at Pittsburgh
Pittsburgh, Pennsylvania
Pittsburgh is the second-largest city in the US Commonwealth of Pennsylvania and the county seat of Allegheny County. Regionally, it anchors the largest urban area of Appalachia and the Ohio River Valley, and nationally, it is the 22nd-largest urban area in the United States...
in 1938. A form of ILS was adopted by the ICAO for international use in 1949.
Following the development of radar
Radar
Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...
in World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
, it was deployed as a landing aid for civil aviation in the form of Ground-controlled approach
Ground-controlled approach
In aviation a ground-controlled approach , is a type of service provided by air-traffic controllers whereby they guide aircraft to a safe landing in adverse weather conditions based on radar images...
(GCA
GCA
GCA may refer to:*Games Convention Asia - A Video Games and interactive technology convention held annually in Singapore consisting of a public exhibition and a professional conference....
) systems, joined in 1948 by distance measuring equipment
Distance Measuring Equipment
Distance measuring equipment is a transponder-based radio navigation technology that measures distance by timing the propagation delay of VHF or UHF radio signals....
(DME), and in the 1950s by airport surveillance radar
Airport Surveillance Radar
An airport surveillance radar is a radar system used at airports to detect and display the position of aircraft in the terminal area.-Digital Airport Surveillance Radar :...
as an aid to air traffic control
Air traffic control
Air traffic control is a service provided by ground-based controllers who direct aircraft on the ground and in the air. The primary purpose of ATC systems worldwide is to separate aircraft to prevent collisions, to organize and expedite the flow of traffic, and to provide information and other...
. VHF omnidirectional range
VHF omnidirectional range
VOR, short for VHF omnidirectional radio range, is a type of radio navigation system for aircraft. A VOR ground station broadcasts a VHF radio composite signal including the station's identifier, voice , and navigation signal. The identifier is typically a two- or three-letter string in Morse code...
(VOR) stations became the predominate means of route navigation during the 1960s, superseding the low frequency radio ranges and the Non-directional beacon
Non-directional beacon
A non-directional beacon is a radio transmitter at a known location, used as an aviation or marine navigational aid. As the name implies, the signal transmitted does not include inherent directional information, in contrast to other navigational aids such as low frequency radio range, VHF...
(NDB). The ground based VOR stations were often co-located with DME transmitters and then labeled as VOR-DME stations on navigation charts. VORTAC stations, which combined VOR and TACAN features (military TACtical Air Navigation) — the latter including both a DME distance feature and a separate TACAN azimuth feature, which provides military pilots data similar to the civilian VOR, were also used in that new system. With the proper receiving equipment in the aircraft, pilots could know their radials in degrees to/from the VOR station, as well as the slant range distance to/from, if the station was co-located with DME or TACAN.
All of the ground-based navigation aids are being supplemented by satellite
Satellite
In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....
-based aids like Global Positioning System
Global Positioning System
The Global Positioning System is a space-based global navigation satellite system that provides location and time information in all weather, anywhere on or near the Earth, where there is an unobstructed line of sight to four or more GPS satellites...
(GPS), which make it possible for aircrews to know their position with great precision anywhere in the world. With the arrival of Wide Area Augmentation System
Wide Area Augmentation System
The Wide Area Augmentation System is an air navigation aid developed by the Federal Aviation Administration to augment the Global Positioning System , with the goal of improving its accuracy, integrity, and availability...
(WAAS), GPS navigation has become accurate enough for vertical (altitude) as well as horizontal use, and is being used increasingly for
instrument approaches as well as en-route navigation. However, since the GPS constellation is a single point of failure
Single point of failure
A single point of failure is a part of a system that, if it fails, will stop the entire system from working. They are undesirable in any system with a goal of high availability or reliability, be it a business practice, software application, or other industrial system.-Overview:Systems can be made...
that can be switched off by the U.S. military
Military of the United States
The United States Armed Forces are the military forces of the United States. They consist of the Army, Navy, Marine Corps, Air Force, and Coast Guard.The United States has a strong tradition of civilian control of the military...
in time of crisis, onboard Inertial Navigation System
Inertial navigation system
An inertial navigation system is a navigation aid that uses a computer, motion sensors and rotation sensors to continuously calculate via dead reckoning the position, orientation, and velocity of a moving object without the need for external references...
(INS) or ground-based navigation aids are still required for backup.
Foreign object debris
Foreign object debris (FOD) includes items left in the aircraft structure during manufacture/repairs, debris on the runway and solids encountered in flight (e.g. hail and dust). Such items can damage engines and other parts of the aircraft. Air France Flight 4590Air France Flight 4590
Air France Flight 4590 was a Concorde flight operated by Air France which was scheduled to run from Charles de Gaulle International Airport near Paris, to John F. Kennedy International Airport in New York City. On 2000, it crashed in Gonesse, France. All one hundred passengers and nine crew...
crashed after hitting a part that had fallen from another aircraft.
Misleading information and lack of information
A pilot might fly the plane in an accident-prone manner when misinformed by a printed document (manual, map etc.), by reacting to a faulty instrument or indicator (either in cockpit or on ground) or by following inaccurate instructions or information from flight or ground control. Lack of information by the control tower, or delayed instructions, are major factors contributing to accidents.Lightning
Boeing studies have shown that airliners are struck by lightningLightning
Lightning is an atmospheric electrostatic discharge accompanied by thunder, which typically occurs during thunderstorms, and sometimes during volcanic eruptions or dust storms...
on average of twice per year. While the "flash and bang" is startling to the passengers and crew, aircraft are able to withstand normal lightning strikes.
The dangers of more powerful positive lightning were not understood until the destruction of a glider
Glider (sailplane)
A glider or sailplane is a type of glider aircraft used in the sport of gliding. Some gliders, known as motor gliders are used for gliding and soaring as well, but have engines which can, in some cases, be used for take-off or for extending a flight...
in 1999. It has since been suggested that positive lightning may have caused the crash of Pan Am
Pan American World Airways
Pan American World Airways, commonly known as Pan Am, was the principal and largest international air carrier in the United States from 1927 until its collapse on December 4, 1991...
Flight 214
Pan Am Flight 214
Pan Am Flight 214, a Boeing 707-121 registered as , was en route from Baltimore to Philadelphia on December 8, 1963, when it crashed near Elkton, Maryland after being hit by lightning, killing all 81 on board.-Flight history:...
in 1963. At that time aircraft were not designed to withstand such strikes, since their existence was unknown at the time standards were set. The 1985 standard in force at the time of the glider crash, Advisory Circular AC 20-53A, was replaced by Advisory Circular AC 20-53B in 2006, however it is unclear whether adequate protection against positive lightning was incorporated.
The effects of normal lightning on traditional metal-covered aircraft are well understood and serious damage from a lightning strike on an airplane is rare. However, as more and more aircraft, like the upcoming Boeing 787
Boeing 787
The Boeing 787 Dreamliner is a long-range, mid-size wide-body, twin-engine jet airliner developed by Boeing Commercial Airplanes. It seats 210 to 290 passengers, depending on the variant. Boeing states that it is the company's most fuel-efficient airliner and the world's first major airliner to use...
, whose whole exterior is made of non-conducting composite material
Composite material
Composite materials, often shortened to composites or called composition materials, are engineered or naturally occurring materials made from two or more constituent materials with significantly different physical or chemical properties which remain separate and distinct at the macroscopic or...
s take to the skies, additional design effort and testing must be made before certification authorities will permit these aircraft in commercial service.
Ice and snow
Ice and snowSnow
Snow is a form of precipitation within the Earth's atmosphere in the form of crystalline water ice, consisting of a multitude of snowflakes that fall from clouds. Since snow is composed of small ice particles, it is a granular material. It has an open and therefore soft structure, unless packed by...
can be factors in airline accidents. In 2005, Southwest Airlines Flight 1248
Southwest Airlines Flight 1248
Southwest Airlines Flight 1248 was a scheduled passenger flight from Baltimore-Washington International Airport, in Baltimore, Maryland, to Chicago Midway International Airport, in Chicago, Illinois, to Salt Lake City International Airport in Salt Lake City, Utah, and then to McCarran...
slid off the end of a runway
Runway
According to ICAO a runway is a "defined rectangular area on a land aerodrome prepared for the landing and take-off of aircraft." Runways may be a man-made surface or a natural surface .- Orientation and dimensions :Runways are named by a number between 01 and 36, which is generally one tenth...
after landing in heavy snow conditions, killing one child.
Even a small amount of icing
Atmospheric icing
Atmospheric icing occurs when water droplets in the atmosphere freeze on objects they contact. This can be extremely dangerous to aircraft, as the built-up ice changes the aerodynamics of the flight surfaces, which can increase the risk of a subsequent stalling of the airfoil...
or coarse frost
Frost
Frost is the solid deposition of water vapor from saturated air. It is formed when solid surfaces are cooled to below the dew point of the adjacent air as well as below the freezing point of water. Frost crystals' size differ depending on time and water vapour available. Frost is also usually...
can greatly impair the ability of a wing to develop adequate lift
Lift (force)
A fluid flowing past the surface of a body exerts a surface force on it. Lift is the component of this force that is perpendicular to the oncoming flow direction. It contrasts with the drag force, which is the component of the surface force parallel to the flow direction...
, which is why regulations prohibit ice, snow or even frost on the wings or tail, prior to takeoff. Air Florida Flight 90
Air Florida Flight 90
Air Florida Flight 90 was a scheduled U.S. domestic passenger flight from Washington National Airport in Arlington County, Virginia, to Fort Lauderdale – Hollywood International Airport in Fort Lauderdale, Florida, with a stopover at Tampa International Airport in Tampa, Florida...
crashed on takeoff in 1982, as a result of ice/snow on its wings.
An accumulation of ice during flight can be catastrophic, as evidenced by the loss of control and subsequent crashes of American Eagle
American Eagle Airlines
American Eagle Airlines is a brand name used by American Eagle Airlines, Inc. , based in Fort Worth, Texas, and Executive Airlines based in San Juan, Puerto Rico, in the operation of passenger air service as regional affiliates of American Airlines. All three airlines are wholly owned subsidiaries...
Flight 4184
American Eagle Flight 4184
American Eagle Flight 4184 was an American Eagle ATR 72 that crashed after flying into unknown icing conditions on October 31, 1994. Control was lost and all aboard were killed.-History:...
in 1994, and Comair Flight 3272
Comair Flight 3272
Comair Flight 3272 was a Comair flight departing on January 9, 1997, from Cincinnati/Northern Kentucky International Airport for the Detroit Metropolitan Wayne County Airport. While on approach for landing, the aircraft, an Embraer EMB 120 Brasilia, crashed nose-down 18 miles short of the airport...
in 1997. Both aircraft were turboprop
Turboprop
A turboprop engine is a type of turbine engine which drives an aircraft propeller using a reduction gear.The gas turbine is designed specifically for this application, with almost all of its output being used to drive the propeller...
airliners, with straight wings, which tend to be more susceptible to inflight ice accumulation, than are swept-wing jet airliners.
Airlines and airports ensure that aircraft are properly de-iced
Deicing
For snow and ice control on roadways and similar facilities, see Snow removalDe-icing is defined as removal of snow, ice or frost from a surface...
before takeoff
Takeoff
Takeoff is the phase of flight in which an aerospace vehicle goes from the ground to flying in the air.For horizontal takeoff aircraft this usually involves starting with a transition from moving along the ground on a runway. For balloons, helicopters and some specialized fixed-wing aircraft , no...
whenever the weather involves icing conditions
Icing conditions
In aviation, icing conditions are those atmospheric conditions that can lead to the formation of water ice on the surfaces of an aircraft, or within the engine as carburetor icing. Inlet icing is another engine-related danger, often occurring in jet aircraft. These icing phenomena do not...
. Modern airliners are designed to prevent ice buildup on wing
Wing
A wing is an appendage with a surface that produces lift for flight or propulsion through the atmosphere, or through another gaseous or liquid fluid...
s, engines
Aircraft engine
An aircraft engine is the component of the propulsion system for an aircraft that generates mechanical power. Aircraft engines are almost always either lightweight piston engines or gas turbines...
, and tails (empennage
Empennage
The empennage , also known as the tail or tail assembly, of most aircraft gives stability to the aircraft, in a similar way to the feathers on an arrow...
) by either routing heated air from jet engine
Jet engine
A jet engine is a reaction engine that discharges a fast moving jet to generate thrust by jet propulsion and in accordance with Newton's laws of motion. This broad definition of jet engines includes turbojets, turbofans, rockets, ramjets, pulse jets...
s through the leading edge
Leading edge
The leading edge is the part of the wing that first contacts the air; alternatively it is the foremost edge of an airfoil section. The first is an aerodynamic definition, the second a structural one....
s of the wing, and inlets, or on slower aircraft, by use of inflatable rubber "boots
Deicing boot
A deicing boot is a type of ice protection system installed on aircraft surfaces to permit a mechanical deicing in flight. Such boots are generally installed on the leading edges of wings and control surfaces A deicing boot is a type of ice protection system installed on aircraft surfaces to permit...
" that expand to break off any accumulated ice.
Airline flight plans require airline dispatch offices to monitor the progress of weather along the routes of their flights, helping the pilots
Aviator
An aviator is a person who flies an aircraft. The first recorded use of the term was in 1887, as a variation of 'aviation', from the Latin avis , coined in 1863 by G. de la Landelle in Aviation Ou Navigation Aérienne...
to avoid the worst of inflight icing conditions. Aircraft can also be equipped with an ice detector
Ice detector
An ice detector is an optical transducer probe available for aviation purposes. It has no moving parts, is completely solid and its principle of operation is entirely optical. Intrusive to the airstream and hermetically sealed, it uses un-collimated light to monitor the opacity and optical...
in order to warn pilots to leave unexpected ice accumulation areas, before the situation becomes critical.
Engine failure
An engine may fail to function because of fuel starvationFuel Starvation
Fuel starvation and fuel exhaustion are problems that can affect internal combustion engines fuelled by either diesel, kerosene, petroleum or any other combustible liquid or gas. If no fuel is available for an engine to burn, it cannot function...
(e.g. British Airways Flight 38
British Airways Flight 38
British Airways Flight 38 was a scheduled flight from Beijing Capital International Airport which crash landed just short of the runway at its destination, London Heathrow Airport, on 17 January 2008 after an flight. There were no fatalities, but 47 people sustained injuries...
), fuel exhaustion (e.g. Gimli Glider
Gimli Glider
The Gimli Glider is the nickname of the Air Canada aircraft that was involved in a notable aviation incident. On 23 July 1983, Air Canada Flight 143, a Boeing 767-200 jet, ran out of fuel at an altitude of ASL, about halfway through its flight from Montreal to Edmonton via Ottawa...
), foreign object damage
Foreign object damage
Foreign Object Debris is a substance, debris or article alien to a vehicle or system which would potentially cause damage.Foreign Object Damage is any damage attributed to a foreign object that can be expressed in physical or economic terms that may or may not degrade the product's required...
(e.g. US Airways Flight 1549
US Airways Flight 1549
US Airways Flight 1549 was US Airways' scheduled domestic commercial passenger flight from LaGuardia Airport in New York City to Charlotte/Douglas International Airport, Charlotte, North Carolina...
), mechanical failure due to metal fatigue
Metal Fatigue
Metal Fatigue , is a futuristic science fiction, real-time strategy computer game developed by Zono Incorporated and published by Psygnosis and TalonSoft .-Plot:...
(e.g. Kegworth air disaster
Kegworth air disaster
The Kegworth Air Disaster occurred on 8 January 1989, when British Midland Flight 92, a Boeing 737–400, crashed onto the embankment of the M1 motorway near Kegworth, Leicestershire, in England. The aircraft was attempting to conduct an emergency landing at East Midlands Airport...
, El Al Flight 1862
El Al Flight 1862
On 4 October 1992, El Al Flight 1862, a Boeing 747 cargo plane of the Israeli airline El Al, crashed into the Groeneveen and Klein-Kruitberg flats in the Bijlmermeer neighbourhood of Amsterdam, the Netherlands. For the location in the Bijlmermeer, the crash is known in Dutch as the "Bijlmerramp"...
, China Airlines Flight 358
China Airlines Flight 358
China Airlines Flight 358 was a Boeing 747-2R7F freighter plane that crashed on December 29, 1991 shortly after takeoff from Chiang Kai-shek International Airport in Taipei, Taiwan. The aircraft was a 747, registration B-198, that had been in service for 11 years, 3 months . The aircraft had...
), mechanical failure due to improper maintenance (e.g. American Airlines Flight 191
American Airlines Flight 191
American Airlines Flight 191 was a regularly scheduled passenger flight in the United States from O'Hare International Airport in Chicago, Illinois, to Los Angeles International Airport. On May 25, 1979, the McDonnell Douglas DC-10-10 operating the route crashed moments after takeoff from Chicago....
), mechanical failure caused by an original manufacturing defect in the engine (e.g. Qantas Flight 32
Qantas Flight 32
Qantas Flight 32 was a Qantas passenger flight that on 4 November 2010 suffered an uncontained engine failure and was forced to make an emergency landing at Singapore Changi Airport. The failure was the first of its kind for the four-engined Airbus A380, the world's largest passenger aircraft...
, United Airlines Flight 232
United Airlines Flight 232
United Airlines Flight 232 was a scheduled flight from Stapleton International Airport in Denver, Colorado, to O'Hare International Airport in Chicago, with continuing service to Philadelphia International Airport...
, Delta Air Lines Flight 1288
Delta Air Lines Flight 1288
Delta Air Lines Flight 1288 was a regularly scheduled flight from Pensacola, Florida to Atlanta, Georgia on a McDonnell-Douglas MD-88 equipped with Pratt & Whitney JT8D-219 turbofan engines...
), and pilot error (e.g. Pinnacle Airlines Flight 3701
Pinnacle Airlines Flight 3701
Pinnacle Airlines Flight 3701 crashed on October 14, 2004, near Jefferson City, Missouri, United States. It was an overnight ferry flight from Little Rock, Arkansas, U.S. to Minneapolis-St. Paul International Airport, U.S...
).
In a multi-engine aircraft, failure of a single engine usually results in a precautionary landing being performed, for example landing at a diversion airport
Diversion airport
Diversion airports are suitable airports capable of handling a particular ETOPS rated aircraft during an emergency landing and whose flying distance at the point of emergency shall not exceed the ETOPS diversion period of that particular aircraft....
instead of continuing to the intended destination. Failure of a second engine (e.g. Dominicana DC-9 air disaster
Dominicana DC-9 air disaster
The Dominicana de Aviación Santo Domingo DC-9 air disaster occurred on February 15, 1970 when a Dominicana de Aviación McDonnell Douglas DC-9-32 twin-engine jet airliner crashed on takeoff from Santo Domingo, Dominican Republic en route to San Juan, Puerto Rico.The aircraft used for the Dominicana...
) or damage to other aircraft systems caused by an uncontained engine failure (e.g. United Airlines Flight 232
United Airlines Flight 232
United Airlines Flight 232 was a scheduled flight from Stapleton International Airport in Denver, Colorado, to O'Hare International Airport in Chicago, with continuing service to Philadelphia International Airport...
) may, if an emergency landing
Emergency landing
An emergency landing is a landing made by an aircraft in response to a crisis which either interferes with the operation of the aircraft or involves sudden medical emergencies necessitating diversion to the nearest airport.-Types of emergency landings:...
is not possible, result in the aircraft crashing.
Structural failure of the aircraft
Examples of failure of aircraft structures caused by metal fatigueFatigue (material)
'In materials science, fatigue is the progressive and localized structural damage that occurs when a material is subjected to cyclic loading. The nominal maximum stress values are less than the ultimate tensile stress limit, and may be below the yield stress limit of the material.Fatigue occurs...
include the De Havilland Comet
De Havilland Comet
The de Havilland DH 106 Comet was the world's first commercial jet airliner to reach production. Developed and manufactured by de Havilland at the Hatfield, Hertfordshire, United Kingdom headquarters, it first flew in 1949 and was a landmark in aeronautical design...
accidents (1950s) and Aloha Airlines Flight 243
Aloha Airlines Flight 243
Aloha Airlines Flight 243 was a scheduled Aloha Airlines flight between Hilo and Honolulu in Hawaii. On April 28, 1988, a Boeing 737-200 serving the flight suffered extensive damage after an explosive decompression in flight, but was able to land safely at Kahului Airport on Maui. The only...
(1988). Now that the subject is better understood, rigorous inspection and nondestructive testing
Nondestructive testing
Nondestructive testing or Non-destructive testing is a wide group of analysis techniques used in science and industry to evaluate the properties of a material, component or system without causing damage....
procedures are in place.
Composite material
Composite material
Composite materials, often shortened to composites or called composition materials, are engineered or naturally occurring materials made from two or more constituent materials with significantly different physical or chemical properties which remain separate and distinct at the macroscopic or...
s consist of layers of fiber
Fiber
Fiber is a class of materials that are continuous filaments or are in discrete elongated pieces, similar to lengths of thread.They are very important in the biology of both plants and animals, for holding tissues together....
s embedded in a resin
Resin
Resin in the most specific use of the term is a hydrocarbon secretion of many plants, particularly coniferous trees. Resins are valued for their chemical properties and associated uses, such as the production of varnishes, adhesives, and food glazing agents; as an important source of raw materials...
matrix. In some cases, especially when subjected to cyclic stress
Cyclic stress
Cyclic stress in engineering refers to an internal distribution of forces that changes over time in a repetitive fashion. As an example, consider one of the large wheels used to drive an aerial lift such as a ski lift. The wire cable wrapped around the wheel exerts a downward force on the wheel...
, the layers of the material separate from each other (delaminate
Delamination
Delamination is a mode of failure for composite materials. Modes of failure are also known as 'failure mechanisms'. In laminated materials, repeated cyclic stresses, impact, and so on can cause layers to separate, forming a mica-like structure of separate layers, with significant loss of mechanical...
) and lose strength. As the failure develops inside the material, nothing is shown on the surface; instrument methods (often ultrasound
Ultrasound
Ultrasound is cyclic sound pressure with a frequency greater than the upper limit of human hearing. Ultrasound is thus not separated from "normal" sound based on differences in physical properties, only the fact that humans cannot hear it. Although this limit varies from person to person, it is...
-based) have to be used to detect such a material failure. In the 1940s several Yakovlev Yak-9
Yakovlev Yak-9
The Yakovlev Yak-9 was a single-engine fighter aircraft used by the Soviet Union in World War II and after. Fundamentally a lighter development of the Yak-7 with the same armament, it arrived at the front at the end of 1942. The Yak-9 had a lowered rear fuselage decking and all-around vision canopy...
s experienced delamination of plywood
Plywood
Plywood is a type of manufactured timber made from thin sheets of wood veneer. It is one of the most widely used wood products. It is flexible, inexpensive, workable, re-usable, and can usually be locally manufactured...
in their construction.
Stalling
StallStall (flight)
In fluid dynamics, a stall is a reduction in the lift coefficient generated by a foil as angle of attack increases. This occurs when the critical angle of attack of the foil is exceeded...
ing an aircraft (increasing the angle of attack
Angle of attack
Angle of attack is a term used in fluid dynamics to describe the angle between a reference line on a lifting body and the vector representing the relative motion between the lifting body and the fluid through which it is moving...
to a point at which the wings fail to produce enough lift
Lift (force)
A fluid flowing past the surface of a body exerts a surface force on it. Lift is the component of this force that is perpendicular to the oncoming flow direction. It contrasts with the drag force, which is the component of the surface force parallel to the flow direction...
), is dangerous and can result in a crash if the pilot fails to quickly react in the proper manner. The only way to recover with a minimum loss of altitude, is to lower the nose (reduces the angle of attack of the wings, so that the boundary layer
Boundary layer
In physics and fluid mechanics, a boundary layer is that layer of fluid in the immediate vicinity of a bounding surface where effects of viscosity of the fluid are considered in detail. In the Earth's atmosphere, the planetary boundary layer is the air layer near the ground affected by diurnal...
re-attaches to the wing), while commanding maximum power from the engines. If the pilot delays initiating that kind of response, a crash is inevitable if the plane is not high enough above all terrain, when the stall occurs.
Devices have been developed to warn the pilot when the plane's speed is coming close to the stall speed. These include stall warning horns (now standard on virtually all powered aircraft), stick shaker
Stick shaker
A stick shaker is a mechanical device to rapidly and noisily vibrate the control yoke of an aircraft to warn the pilot of an imminent stall...
s and voice warnings. Most stalls are a result of the pilot allowing the plane to go too slow for the particular weight and configuration at the time. The stall speed is higher on virtually all aircraft, if ice or even frost has attached to the wings and/or horizontal tail stabilizer. The more severe the icing, the higher will be the stall speed, not only because smooth airflow over the wings becomes increasingly more difficult, but also because of the added weight of the accumulated ice.
"High speed stalls" are also possible, if a pilot tries to pull out of a dive so quickly that he increases the angle of attack to the point of boundary layer separation of the airflow over the wings. Again, the only solution is to lower the nose somewhat, even though the plane is already diving at high speed, and then to resume the pull-out with a less severe angle of attack.
Crashes, caused by a full stall of the airfoils include:
- British European Airways Flight 548British European Airways Flight 548British European Airways Flight 548 was a Hawker Siddeley Trident 1C airliner, registration G-ARPI, operating as a British European Airways scheduled commercial passenger flight from London Heathrow Airport to Brussels, Belgium...
(1972) - United Airlines Flight 553United Airlines Flight 553United Airlines Flight 553 was a Boeing 737-222 that crashed on approach to Chicago Midway International Airport at 2:28 p.m. CST, on December 8, 1972. After the crew was told to go around and abort their first landing attempt on runway 31L at Midway Airport, the aircraft struck trees and then...
(1972) - Aeroflot Flight 7425Aeroflot Flight 7425Aeroflot Flight 7425 refers to a Tupolev Tu-154B-2, registration CCCP-85311, that was operating a domestic scheduled Tashkent–Karshi–Orenburg–Leningrad passenger service under the airline's Uzbekistan division, that crashed near Uchkuduk, Uzbek SSR, Soviet Union, while en route its second leg...
(1985) - Arrow Air Flight 1285Arrow Air Flight 1285Arrow Air Flight 1285 was a McDonnell Douglas DC-8-63CF jetliner, registered N950JW, which operated as an international charter flight carrying U.S. troops from Cairo, Egypt, to their home base in Fort Campbell, Kentucky, via Cologne, Germany and Gander, Newfoundland...
(1985) - Northwest Airlines Flight 255Northwest Airlines Flight 255Northwest Airlines Flight 255 was a flight that originated at MBS International Airport in Saginaw, Michigan, and was scheduled to terminate at John Wayne Airport in Orange County, California, with intermediate stops at Detroit Metropolitan Wayne County Airport in Romulus, Michigan, near Detroit,...
(1987) - The Paul WellstonePaul WellstonePaul David Wellstone was a two-term U.S. Senator from the state of Minnesota and member of the Democratic-Farmer-Labor Party, which is affiliated with the national Democratic Party. Before being elected to the Senate in 1990, he was a professor of political science at Carleton College...
crash (2002) - Colgan Air Flight 3407Colgan Air Flight 3407Colgan Air Flight 3407, marketed as Continental Connection under a codeshare agreement with Continental Airlines, was a daily U.S. regional airline commuter flight from Newark Liberty International Airport in New Jersey to Buffalo Niagara International Airport in New York State.A Bombardier...
(2009)
Fire
Toxicity
Toxicity is the degree to which a substance can damage a living or non-living organisms. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a substructure of the organism, such as a cell or an organ , such as the liver...
of smoke
Smoke
Smoke is a collection of airborne solid and liquid particulates and gases emitted when a material undergoes combustion or pyrolysis, together with the quantity of air that is entrained or otherwise mixed into the mass. It is commonly an unwanted by-product of fires , but may also be used for pest...
. When the tests fail, they fail on a prototype in an engineering laboratory, rather than in an aircraft.
Fire on board the aircraft, and more especially the toxic smoke generated, have been the cause of accidents. An electrical fire on Air Canada Flight 797
Air Canada Flight 797
Air Canada Flight 797 was a scheduled trans-border flight that flew on a Dallas/Fort Worth-Toronto-Montreal route. On , the aircraft developed an in-flight fire behind the washroom that spread between the outer skin and the inner decor panels, filling the plane with toxic smoke...
in 1983 caused the deaths of 23 of the 46 passengers, resulting in the introduction of floor level lighting to assist people to evacuate a smoke-filled aircraft. Two years later a fire on the runway caused the loss of 55 lives, 48 from the effects of incapacitating and subsequently lethal toxic gas and smoke, in the 1985 British Airtours
British Airtours
British Airtours was a UK charter airline with flight operations out of London Gatwick and Manchester Airport.Originally established as BEA Airtours in 1969, it became a wholly owned subsidiary of then state-owned British Airways following the British European Airways — British Overseas Airways...
Flight 28M
British Airtours Flight 28M
British Airtours Flight 28M was an international passenger flight on 22 August 1985 which originated from Manchester International Airport's Runway 24 in Manchester, England en-route to Corfu International Airport on the Greek island of Corfu. The aircraft, previously named "Goldfinch" but at the...
. That accident raised serious concerns relating to survivability, something that prior to 1985 had not been studied in such detail. The swift incursion of the fire into the fuselage and the layout of the aircraft impaired passengers' ability to evacuate, with areas such as the forward galley area becoming a bottle-neck for escaping passengers, with some dying very close to the exits. A large amount of research into evacuation and cabin and seating layouts was carried at Cranfield Institute
Cranfield Institute
The Cranfield Institute for Safety, Risk and Reliability is a part of Cranfield University in the UK. It is primarily a teaching and research facility, but also offers safety-related consultancy to businesses.- Facilities :The Cranfield Institute has several simulators designed for risk and hazard...
to try to measure what makes a good evacuation route, which led to the seat layout by Overwing exits
Overwing exits
Overwing exits are found on passenger aircraft to provide a means of passenger evacuation onto the wing, where they either continue off the trailing edge by sliding down the extended flaps or by using an evacuation slide that deploys when the exit is opened....
being changed by mandate and the examination of evacuation requirements relating to the design of galley areas. The use of smoke hood
Smoke hood
A smoke hood is a protective device similar in concept to a gas mask. A translucent airtight bag seals around the head of the wearer while an air filter held in the mouth connects to the outside atmosphere and is used to breathe...
s or misting systems were also examined although both were rejected.
South African Airways Flight 295
South African Airways Flight 295
South African Airways Flight 295 was a commercial flight that suffered a catastrophic in-flight fire in the cargo area and crashed into the Indian Ocean east of Mauritius on 28 November 1987, killing everyone on board...
was lost in the Indian Ocean in 1987 after an in-flight fire in the cargo hold could not be suppressed by the crew. The cargo holds of most airliners are now equipped with automated halon
Halomethane
Halomethane compounds are derivatives of methane with one or more of the hydrogen atoms replaced with halogen atoms . Halomethanes are both naturally occurring, especially in marine environments, and man-made, most notably as refrigerants, solvents, propellants, and fumigants...
fire extinguishing
Fire extinguisher
A fire extinguisher or extinguisher, flame entinguisher is an active fire protection device used to extinguish or control small fires, often in emergency situations...
systems to combat a fire that might occur in the baggage holds. In May 1996 ValuJet Airlines
ValuJet Airlines
ValuJet Airlines was an American low-cost carrier, headquartered in unincorporated Clayton County, Georgia, that operated regularly scheduled domestic and international flights in the Eastern United States and Canada during the 1990s...
Flight 592
ValuJet Flight 592
ValuJet Flight 592 was a scheduled domestic passenger flight between Miami International Airport, Miami, Florida, and William B. Hartsfield Atlanta International Airport, Atlanta, Georgia...
crashed into the Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
Everglades
Everglades
The Everglades are subtropical wetlands in the southern portion of the U.S. state of Florida, comprising the southern half of a large watershed. The system begins near Orlando with the Kissimmee River, which discharges into the vast but shallow Lake Okeechobee...
a few minutes after takeoff after a fire broke out in the forward cargo hold. All 110 aboard were killed.
At one time fire fighting
Fire fighting
Firefighting is the act of extinguishing fires. A firefighter fights fires to prevent loss of life, and/or destruction of property and the environment...
foam path
Foam path
A foam path is the aviation safety practice of spreading a layer of fire suppression foam on an airport runway prior to an emergency landing. Originally, it was thought this would prevent fires, but the practice is now discouraged....
s were laid down before an emergency landing, but the practice was considered only marginally effective, and concerns about the depletion of fire fighting capability due to pre-foaming led the United States FAA to withdraw its recommendation in 1987.
One possible cause of fires in airplanes are wiring problems that involve intermittent faults, such as wires with breached insulation touching each other, having water dripping on them, or short circuits. These are difficult to detect once the plane is on the ground. However, there are methods, such as spread-spectrum time-domain reflectometry
Spread-spectrum time-domain reflectometry
Spread-spectrum time-domain reflectometry is a measurement technique to identify faults, usually in electrical wires, by observing reflected spread spectrum signals. SSTDR is a type of time-domain reflectometry that can be advantageous to other systems due to the ability to use SSTDR in high-noise...
, that can feasibly test live wires on aircraft during flight.
Bird strike
Bird strike is an aviation term for a collision between a bird and an aircraft. Fatal accidents have been caused by both engine failure following bird ingestion and bird strikes breaking cockpit windshields.Modern jet engines have the capability of surviving an ingestion of a bird. Small fast planes, such as military jet fighters
Fighter aircraft
A fighter aircraft is a military aircraft designed primarily for air-to-air combat with other aircraft, as opposed to a bomber, which is designed primarily to attack ground targets...
, are at higher risk than heavy multi-engine ones. This is due to the fact that the fan of a high-bypass turbofan
Turbofan
The turbofan is a type of airbreathing jet engine that is widely used for aircraft propulsion. A turbofan combines two types of engines, the turbo portion which is a conventional gas turbine engine, and the fan, a propeller-like ducted fan...
engine, typical on transport aircraft, acts as a centrifugal separator to force ingested materials (birds, ice, etc.) to the outside of the fan's disc. As a result, such materials go through the relatively unobstructed bypass duct
Bypass duct
A bypass duct is an annular passage that allows some of a turbofan's airflow to bypass the engine core, or gas generator. If the turbofan is unmixed, the bypass duct will terminate at the bypass nozzle...
, rather than through the core of the engine, which contains the smaller and more delicate compressor blades. Military aircraft
Military aircraft
A military aircraft is any fixed-wing or rotary-wing aircraft that is operated by a legal or insurrectionary armed service of any type. Military aircraft can be either combat or non-combat:...
designed for high-speed flight typically have pure turbojet, or low-bypass turbofan engines, increasing the risk that ingested materials will get into the core of the engine to cause damage.
The highest risk of the bird strike is during the takeoff and landing
Landing
thumb|A [[Mute Swan]] alighting. Note the ruffled feathers on top of the wings indicate that the swan is flying at the [[Stall |stall]]ing speed...
, in low altitude
Altitude
Altitude or height is defined based on the context in which it is used . As a general definition, altitude is a distance measurement, usually in the vertical or "up" direction, between a reference datum and a point or object. The reference datum also often varies according to the context...
s, which is in the vicinity of the airport
Airport
An airport is a location where aircraft such as fixed-wing aircraft, helicopters, and blimps take off and land. Aircraft may be stored or maintained at an airport...
s. Some airports use active countermeasures, ranging from a person with a shotgun
Shotgun
A shotgun is a firearm that is usually designed to be fired from the shoulder, which uses the energy of a fixed shell to fire a number of small spherical pellets called shot, or a solid projectile called a slug...
through recorded sounds of predators to employing falconer
Falconry
Falconry is "the taking of wild quarry in its natural state and habitat by means of a trained raptor". There are two traditional terms used to describe a person involved in falconry: a falconer flies a falcon; an austringer flies a hawk or an eagle...
s. Poisonous grass can be planted that is not palatable to birds, nor to insects that attract insectivorous
Insectivore
An insectivore is a type of carnivore with a diet that consists chiefly of insects and similar small creatures. An alternate term is entomophage, which also refers to the human practice of eating insects....
birds. Passive countermeasures involve sensible land-use management, avoiding conditions attracting flocks of birds to the area (e.g. landfill
Landfill
A landfill site , is a site for the disposal of waste materials by burial and is the oldest form of waste treatment...
s). Another tactic found effective is to let the grass at the airfield grow taller (approximately 12 inches (30.5 cm)) as some species of birds won't land if they cannot see one another.
Ground damage
Aircraft are occasionally damaged by ground equipmentGround Support Equipment
Ground support equipment is the support equipment found at an airport, usually on the ramp, the servicing area by the terminal. This equipment is used to service the aircraft between flights. As its name implies, GSE is there to support the operations of aircraft on the ground...
at the airport. In the act of servicing the aircraft between flights a great deal of ground equipment must operate in close proximity to the fuselage and wings. Occasionally the aircraft gets bumped or worse.
Damage may be in the form of simple scratches in the paint or small dents in the skin. However, because aircraft structures (including the outer skin) play such a critical role in the safe operation of a flight, all damage is inspected, measured and possibly tested to ensure that any damage is within safe tolerances.
An example of this problem was the depressurization incident on Alaska Airlines
Alaska Airlines
Alaska Airlines is an airline based in the Seattle suburb of SeaTac, Washington in the United States. The airline originated in 1932 as McGee Airways. After many mergers with and acquisitions of other airlines, including Star Air Service, it became known as Alaska Airlines in 1944...
Flight 536 in 2005. During ground services a baggage handler
Baggage handler
In the airline industry, a baggage handler is a person who loads and unloads baggage , and other cargo for transport via aircraft...
hit the side of the aircraft with a tug towing a train of baggage cart
Baggage cart
Baggage carts, luggage carts or trolleys are small vehicles pushed by travelers to carry individual luggage, mostly suitcases. There are two major sizes: One for big luggage and one for small luggage...
s. This damaged the metal skin of the aircraft. This damage was not reported and the plane departed. Climbing through 26000 feet (7,924.8 m) the damaged section of the skin gave way due to the growing difference in pressure between the inside of the aircraft and the outside air. The cabin depressurized
Cabin pressurization
Cabin pressurization is the pumping of compressed air into an aircraft cabin to maintain a safe and comfortable environment for crew and passengers when flying at altitude.-Need for cabin pressurization:...
with a bang necessitating a rapid descent back to denser (breathable) air and an emergency landing. Post landing examination of the fuselage revealed a 12 in (30.5 cm) hole on the right side of the airplane.
Volcanic ash
Plumes of volcanic ashVolcanic ash
Volcanic ash consists of small tephra, which are bits of pulverized rock and glass created by volcanic eruptions, less than in diameter. There are three mechanisms of volcanic ash formation: gas release under decompression causing magmatic eruptions; thermal contraction from chilling on contact...
near active volcano
Volcano
2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...
es can damage propeller
Propeller (aircraft)
Aircraft propellers or airscrews convert rotary motion from piston engines or turboprops to provide propulsive force. They may be fixed or variable pitch. Early aircraft propellers were carved by hand from solid or laminated wood with later propellers being constructed from metal...
s, engines
Aircraft engine
An aircraft engine is the component of the propulsion system for an aircraft that generates mechanical power. Aircraft engines are almost always either lightweight piston engines or gas turbines...
and cockpit windows.
In 1982, British Airways Flight 9
British Airways Flight 9
British Airways Flight 9, sometimes referred to by its callsign Speedbird 9 or Jakarta incident, was a scheduled British Airways flight from London Heathrow to Auckland, with stops in Bombay, Madras, Kuala Lumpur, Perth, and Melbourne....
flew through an ash cloud and temporarily lost power from all four engines.
Prior to 2010 the general approach taken by airspace regulators was that if the ash concentration rose above zero, then the airspace was considered unsafe and was consequently closed.
Volcanic Ash Advisory Center
Volcanic Ash Advisory Center
A Volcanic Ash Advisory Center is a group of experts responsible for coordinating and disseminating information on atmospheric volcanic ash clouds that may endanger aviation. As of 2010, there are nine Volcanic Ash Advisory Centers located around the world, each one focusing on a particular...
s enable liaison between meteorologist
Meteorology
Meteorology is the interdisciplinary scientific study of the atmosphere. Studies in the field stretch back millennia, though significant progress in meteorology did not occur until the 18th century. The 19th century saw breakthroughs occur after observing networks developed across several countries...
s, volcanologist
Volcanology
Volcanology is the study of volcanoes, lava, magma, and related geological, geophysical and geochemical phenomena. The term volcanology is derived from the Latin word vulcan. Vulcan was the ancient Roman god of fire....
s, and the aviation industry.
Human factors
Human factors
Human factors science or human factors technologies is a multidisciplinary field incorporating contributions from psychology, engineering, industrial design, statistics, operations research and anthropometry...
including pilot error
Pilot error
Pilot error is a term used to describe the cause of an accident involving an airworthy aircraft where the pilot is considered to be principally or partially responsible...
are another potential danger, and currently the most common factor of aviation crashes. Much progress in applying human factors to improving aviation safety was made around the time of World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
by people such as Paul Fitts
Paul Fitts
Paul M. Fitts was a psychologist at Ohio State University . He developed a model of human movement, Fitts's law, based on rapid, aimed movement, which went on to become one of the most highly successful and well studied mathematical models of human motion...
and Alphonse Chapanis
Alphonse Chapanis
Alphonse Chapanis was a pioneer in the field of industrial design, and is widely considered one of the fathers of ergonomics or human factors - the science of ensuring that design takes account of human characteristics...
. However, there has been progress in safety throughout the history of aviation, such as the development of the pilot's checklist
Checklist
A checklist is a type of informational job aid used to reduce failure by compensating for potential limits of human memory and attention. It helps to ensure consistency and completeness in carrying out a task...
in 1937. Pilot error and improper communication are often factors in the collision
Collision
A collision is an isolated event which two or more moving bodies exert forces on each other for a relatively short time.Although the most common colloquial use of the word "collision" refers to accidents in which two or more objects collide, the scientific use of the word "collision" implies...
of aircraft. This can take place in the air
Mid-air collision
A mid-air collision is an aviation accident in which two or more aircraft come into contact during flight. Owing to the relatively high velocities involved and any subsequent impact on the ground or sea, very severe damage or the total destruction of at least one of the aircraft involved usually...
(1978 Pacific Southwest Airlines
Pacific Southwest Airlines
Pacific Southwest Airlines was a United States airline headquartered in San Diego, California, that operated from 1949 to 1988. It was one of the first large discount airlines in the United States and is considered a precursor to Southwest Airlines...
Flight 182
PSA Flight 182
Pacific Southwest Airlines Flight 182, registration N533PS, was a Boeing 727-214 commercial airliner that collided with a private Cessna 172 over San Diego, California on September 25, 1978. Pacific Southwest Airlines' first accident involving fatalities, the death toll of 144 makes it the...
) (TCAS) or on the ground (1977 Tenerife disaster
Tenerife disaster
The Tenerife airport disaster occurred on March 27, 1977, when two Boeing 747 passenger aircraft collided on the runway of Los Rodeos Airport on the Spanish island of Tenerife, one of the Canary Islands...
) (RAAS
Runway Awareness and Advisory System
The Runway Awareness and Advisory System is an electronic detection system developed by Honeywell. It provides aircraft flight crews with information concerning the aircraft's position relative to an airport's runway .-Operation:RAAS functions by providing audible alerts to confirm runway...
). The ability of the flight crew to maintain situational awareness is a critical human factor in air safety. Human factors training is available to general aviation pilots and called single pilot resource management training.
Failure of the pilots to properly monitor the flight instruments resulted in the crash of Eastern Air Lines
Eastern Air Lines
Eastern Air Lines was a major United States airline that existed from 1926 to 1991. Before its dissolution it was headquartered at Miami International Airport in unincorporated Miami-Dade County, Florida.-History:...
Flight 401
Eastern Air Lines Flight 401
Eastern Air Lines Flight 401 was a Lockheed L-1011 Tristar 1 jet that crashed into the Florida Everglades on the night of December 29, 1972, causing 101 fatalities...
in 1972 controlled flight into terrain
Controlled flight into terrain
Controlled flight into terrain describes an accident in which an airworthy aircraft, under pilot control, is unintentionally flown into the ground, a mountain, water, or an obstacle. The term was coined by engineers at Boeing in the late 1970s...
(CFIT), and error during take-off and landing can have catastrophic consequences, for example cause the crash of Prinair
Prinair
Prinair was a Puerto Rican airline. It was Puerto Rico's domestic and international flag carrier airline for almost two decades.- History :Services began in 1966, under the name Aerolíneas de Ponce , with Aero Commanders...
Flight 191
Prinair Flight 191
Prinair Flight 191 was a Prinair flight from Luis Muñoz Marín International Airport in San Juan, Puerto Rico, to Mercedita Airport in Ponce, Puerto Rico. At approximately 11:15pm on 24 June 1972, the aircraft crashed while attempting to land at Mercedita Airport...
on landing, also in 1972.
Rarely, flight crew members are arrested or subject to disciplinary action for being intoxicated
Drunkenness
Alcohol intoxication is a physiological state that occurs when a person has a high level of ethanol in his or her blood....
on the job. In 1990, three Northwest Airlines
Northwest Airlines
Northwest Airlines, Inc. was a major United States airline founded in 1926 and absorbed into Delta Air Lines by a merger approved on October 29, 2008, making Delta the largest airline in the world...
crew members were sentenced to jail for flying to Minneapolis
Minneapolis-Saint Paul International Airport
Minneapolis-Saint Paul International Airport is the largest and busiest airport in the five-state upper Midwest region of Minnesota, Iowa, South Dakota, North Dakota, and Wisconsin.-Overview:...
while drunk. In 2001, Northwest fired a pilot who failed a breathalyzer
Breathalyzer
A breathalyzer or breathalyser is a device for estimating blood alcohol content from a breath sample...
test after a flight. In July 2002, two America West Airlines
America West Airlines
America West Airlines corporate offices were in Tempe, Arizona and the main hub was at Phoenix Sky Harbor International Airport. The airline became part of the US Airways Group after a merger in 2005....
pilots were arrested just before they were scheduled to fly because they had been drinking alcohol
Alcohol
In chemistry, an alcohol is an organic compound in which the hydroxy functional group is bound to a carbon atom. In particular, this carbon center should be saturated, having single bonds to three other atoms....
. The pilots have been fired from America West and the FAA revoked their pilot's licenses. As of 2005 they await trial in a Florida court. The incident created a public relations problem and America West has become the object of many jokes about drunk pilots. At least one fatal airliner accident involving drunk pilots has occurred when Aero Flight 311
Aero Flight 311
Aero Flight 311 , often referred to as the Koivulahti air disaster, was a scheduled domestic passenger flight operated by Aero O/Y between Kronoby , Finland and Vaasa. The aircraft, a Douglas DC-3C, crashed near Kvevlax on January 3, 1961, killing all twenty-five people on board...
crashed killing all 25 on board in 1961, which underscores the role that poor human choices can play in air accidents.
Human factors incidents are not limited to errors by the pilots. The failure to close a cargo door properly on Turkish Airlines
Turkish Airlines
Turkish Airlines is the national flag carrier airline of Turkey, headquartered in the Turkish Airlines General Management Building on the grounds of Atatürk Airport in Yeşilköy, Bakirköy district, Istanbul...
Flight 981
Turkish Airlines Flight 981
Turkish Airlines Flight 981 was a McDonnell Douglas DC-10, registered TC-JAV and named the Ankara, that crashed in Fontaine-Chaalis, Oise, France, outside Senlis, on 3 March 1974...
in 1974 resulted in the loss of the aircraft - however the design of the cargo door latch was also a major factor in the accident. In the case of Japan Airlines Flight 123
Japan Airlines Flight 123
Japan Airlines Flight 123 was a Japan Airlines domestic flight from Tokyo International Airport to Osaka International Airport on August 12, 1985. The Boeing 747-146SR that made this route, registered , suffered mechanical failures 12 minutes into the flight and 32 minutes later crashed into two...
, improper maintenance led to explosive decompression of the cabin, which in turn destroyed the vertical stabilizer
Vertical stabilizer
The vertical stabilizers, vertical stabilisers, or fins, of aircraft, missiles or bombs are typically found on the aft end of the fuselage or body, and are intended to reduce aerodynamic side slip. It is analogical to a skeg on boats and ships.On aircraft, vertical stabilizers generally point upwards...
and the integrity of all four hydraulic systems, which powered all the flight controls.
Controlled flight into terrain
Controlled flight into terrain is a class of accident in which an aircraft is flown, under control, into terrain or man-made structures. CFIT accidents typically are a result of pilot error or of navigational system error. Failure to protect Instrument Landing System critical areaCritical area
-Aviation:In aviation, a critical area refers to a designated area of an airport that all aircraft must remain clear of when another aircraft is inbound on an ILS approach. The critical area should be avoided when the weather is less than or equal to 2 miles visibility or less than or equal to...
s can also cause CFIT accidents. One of the most notable CFIT accidents was in December 1995 in which American Airlines flight 965
American Airlines Flight 965
American Airlines Flight 965, a Boeing 757 registered , was a scheduled flight from Miami International Airport in Miami, Florida to Alfonso Bonilla Aragón International Airport in Cali, Colombia, which crashed into a mountain in Buga, Colombia on December 20, 1995, killing 151 passengers and 8...
tracked off course while approaching Calí, Colombia and hit a mountainside despite a ground proximity warning system
Ground Proximity Warning System
A ground proximity warning system is a system designed to alert pilots if their aircraft is in immediate danger of flying into the ground or an obstacle. The United States Federal Aviation Administration defines GPWS as a type of terrain awareness warning system...
terrain warning in the cockpit and desperate pilot attempt to gain altitude after that warning. Crew position awareness and monitoring of navigational systems are essential to the prevention of CFIT accidents. As of February, 2008, over 40,000 aircraft had the Enhanced version of the GPWS system installed, and they had flown over 800 million hours without a single CFIT accident.
Another anti-CFIT tool is the Minumum Safe Altitude Warning (MSAW) system avaiable near many airports. It monitors the altitudes transmitted by aircraft transponders and compares that with the system's defined minimum safe altitudes for a given area. When the system determines the aircraft is lower, or will soon be lower, than the minimum safe altitude (MSA), the air traffic controller receives an acoustic and visual warning and then alerts the pilot that his aircraft is too low.
Electromagnetic interference
The use of certain electronic equipment is partially or entirely prohibited as it may interfere with aircraft operation, such as causing compassCompass
A compass is a navigational instrument that shows directions in a frame of reference that is stationary relative to the surface of the earth. The frame of reference defines the four cardinal directions – north, south, east, and west. Intermediate directions are also defined...
deviations. Use of personal electronic devices and calculator
Calculator
An electronic calculator is a small, portable, usually inexpensive electronic device used to perform the basic operations of arithmetic. Modern calculators are more portable than most computers, though most PDAs are comparable in size to handheld calculators.The first solid-state electronic...
s may be prohibited when an aircraft is below 10,000', taking off, or landing. The American Federal Communications Commission
Federal Communications Commission
The Federal Communications Commission is an independent agency of the United States government, created, Congressional statute , and with the majority of its commissioners appointed by the current President. The FCC works towards six goals in the areas of broadband, competition, the spectrum, the...
(FCC) prohibits the use of a cell phone
Mobile phone
A mobile phone is a device which can make and receive telephone calls over a radio link whilst moving around a wide geographic area. It does so by connecting to a cellular network provided by a mobile network operator...
on most flights, because in-flight usage creates problems with ground-based cells. There is also concern about possible interference with aircraft navigation systems, although that has never been proven to be a non-serious risk on airliners. A few flights now allow use of cell phones, where the aircraft have been specially wired and certified to meet both FAA and FCC regulations.
Runway safety
Types of runway safety incidents include:- Runway excursion - an incident involving only a single aircraft, where it makes an inappropriate exit from the runway.
- Runway overrun - a type of excursion where the aircraft is unable to stop before the end of the runway (e.g. Air France Flight 358Air France Flight 358Air France Flight 358, a flight from Paris, France, to Toronto, Canada, using an Airbus A340 airliner, departed Paris without incident at 11:53 UTC 2 August 2005, later touching down on runway 24L-06R at Toronto Pearson International Airport at 20:01 UTC...
). - Runway incursionRunway incursionA runway incursion is an incident where an unauthorized aircraft, vehicle or person is on a runway. This adversely affects runway safety, as it creates the risk that an airplane taking off or landing will collide with the object...
- an incident involving incorrect presence of a vehicle, person or another aircraft on the runway (e.g. Tenerife disaster). - Runway confusion - an aircraft makes uses the wrong runway for landing or take-off (e.g. Comair Flight 191).
Terrorism
Aircrew are normally trained to handle hijackAircraft hijacking
Aircraft hijacking is the unlawful seizure of an aircraft by an individual or a group. In most cases, the pilot is forced to fly according to the orders of the hijackers. Occasionally, however, the hijackers have flown the aircraft themselves, such as the September 11 attacks of 2001...
situations. Since the September 11, 2001 attacks
September 11, 2001 attacks
The September 11 attacks The September 11 attacks The September 11 attacks (also referred to as September 11, September 11th or 9/119/11 is pronounced "nine eleven". The slash is not part of the pronunciation...
, stricter airport
Airport security
Airport security refers to the techniques and methods used in protecting airports and aircraft from crime.Large numbers of people pass through airports. This presents potential targets for terrorism and other forms of crime due to the number of people located in a particular location...
and airline security
Airline security
Airline security refers to the procedures and infrastructure designed to avoid security problems aboard aircraft. A related area is airport security. Security for air travel is primarily based in airports...
measures are in place to prevent terrorism
Terrorism
Terrorism is the systematic use of terror, especially as a means of coercion. In the international community, however, terrorism has no universally agreed, legally binding, criminal law definition...
.
Deliberate aircrew action
Although most air crews are screened for psychological fitness, some may take suicidal actions. In the case of EgyptAir Flight 990EgyptAir Flight 990
EgyptAir Flight 990 was a regularly scheduled flight from Los Angeles International Airport, California to Cairo International Airport, Egypt, with a stop at John F. Kennedy International Airport, New York...
, it appears that the first officer deliberately dived his aircraft into the Atlantic Ocean
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
while the captain was away from his station, in 1999 off Nantucket, Massachusetts
Nantucket, Massachusetts
Nantucket is an island south of Cape Cod, Massachusetts, in the United States. Together with the small islands of Tuckernuck and Muskeget, it constitutes the town of Nantucket, Massachusetts, and the coterminous Nantucket County, which are consolidated. Part of the town is designated the Nantucket...
. Motivations are unclear, but recorded inputs from the black boxes
Black Box (transportation)
The term black box is a placeholder name used casually to refer to a collection of several different recording devices used in transportation: the flight recorders in aircraft, the event recorder in railway locomotives, the event data recorder in automobiles, message case in ships, and other...
showed no mechanical problem, no other aircraft in the area, and was corroborated by the cockpit voice recorder
Cockpit voice recorder
A cockpit voice recorder , often referred to as a "black box", is a flight recorder used to record the audio environment in the flight deck of an aircraft for the purpose of investigation of accidents and incidents...
.
In 1982, Japan Airlines Flight 350
Japan Airlines Flight 350
Japan Airlines Flight 350 was a McDonnell Douglas DC-8-61, aircraft registration , on a domestic scheduled passenger flight from Fukuoka, Japan, to Tokyo. The airplane crashed 9 February 1982 on approach to Tokyo Haneda Airport in Tokyo Bay...
crashed while on approach to the Tokyo Haneda Airport, killing 24 of the 174 onboard. The official investigation found the mentally ill captain had attempted suicide by placing the inboard engines into reverse thrust, while the plane was close to the runway. The first officer did not have enough time to countermand his actions, before the plane stalled and crashed.
In 1997, SilkAir Flight 185
SilkAir Flight 185
SilkAir Flight 185, a Boeing 737-36N, registration 9V-TRF, was a scheduled passenger flight from Jakarta, Indonesia to Singapore, which crashed on 19 December 1997 into the Musi River after abruptly plunging from its 35,000-foot cruise altitude, killing all 97 passengers and 7 crew on board.The...
suddenly went into a high dive from its cruising altitude. The speed of the dive was so high that the plane began to break apart before it finally crashed near Palembang
Palembang
Palembang is the capital city of the South Sumatra province in Indonesia. Palembang is one of the oldest cities in Indonesia, and has a history of being a capital of a maritime empire. Located on the Musi River banks on the east coast of southern Sumatra island, it has an area of 400.61 square...
, Sumatra
Sumatra
Sumatra is an island in western Indonesia, westernmost of the Sunda Islands. It is the largest island entirely in Indonesia , and the sixth largest island in the world at 473,481 km2 with a population of 50,365,538...
. After three years of investigation, the Indonesian autorities declared that the cause of the accident can not be determined. However, the US NTSB concluded that deliberate suicide by the Captain, was the only reasonable explanation for the cause of that crash.
Attack by a hostile country
Aircraft, whether passenger planes or military aircraft, are sometimes attacked in both peacetime and war. Examples of this include:- In 1973 Israeli F-4 Phantom IIF-4 Phantom IIThe McDonnell Douglas F-4 Phantom II is a tandem two-seat, twin-engined, all-weather, long-range supersonic jet interceptor fighter/fighter-bomber originally developed for the United States Navy by McDonnell Aircraft. It first entered service in 1960 with the U.S. Navy. Proving highly adaptable,...
s shot down Libyan Arab Airlines Flight 114Libyan Arab Airlines Flight 114Libyan Arab Airlines Flight 114 was a regularly scheduled flight from Tripoli to Cairo via Benghazi shot down by Israeli fighter jets in 1973....
. - In 1983 the Soviet Air Defence Forces shot down Korean Air Lines Flight 007.
- In 1988 the United States NavyUnited States NavyThe United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...
shot down Iran Air Flight 655Iran Air Flight 655Iran Air Flight 655 was a civilian jet airliner shot down by U.S. missiles on 3 July 1988, over the Strait of Hormuz, toward the end of the Iran–Iraq War...
. - In 2001 the Ukrainian Air ForceUkrainian Air ForceThe Ukrainian Air Force is a part of the Armed Forces of Ukraine. Ukrainian Air Force Command and headquarters are located in the city of Vinnytsia....
shot down Siberia Airlines Flight 1812Siberia Airlines Flight 1812Siberia Airlines Flight 1812 crashed over the Black Sea on 4 October 2001, en route from Tel Aviv, Israel to Novosibirsk, Russia. The plane, a Soviet-made Tupolev Tu-154, carried an estimated 66 passengers and 12 crew members. No one on board survived...
.
Accident survivability
Airport design
Airport design and location can have a big impact on air safety, especially since some airports such as Chicago Midway International Airport were originally built for propeller planes and many airports are in congested areas where it is difficult to meet newer safety standards. For instance, the FAA issued rules in 1999 calling for a runway safety areaRunway safety area
A runway safety area or runway end safety area is defined as "the surface surrounding the runway prepared or suitable for reducing the risk of damage to airplanes in the event of an undershoot, overshoot, or excursion from the runway."Past standards called for the RSA to extend only 60m from the...
, usually extending 500 feet (152.4 m) to each side and 1000 feet (304.8 m) beyond the end of a runway. This is intended to cover ninety percent of the cases of an aircraft leaving the runway by providing a buffer space free of obstacles. Since this is a recent rule, many airports do not meet it. One method of substituting for the 1000 feet (304.8 m) at the end of a runway for airports in congested areas is to install an Engineered materials arrestor system
Engineered Materials Arrestor System
An engineered materials arrestor system or engineered materials arresting system is a bed of engineered materials built at the end of a runway. Engineered materials are defined in FAA Advisory Circular No 150/5220-22A as "high energy absorbing materials of selected strength, which will reliably...
, or EMAS. These systems are usually made of a lightweight, crushable concrete that absorbs the energy of the aircraft to bring it to a rapid stop. They have stopped three aircraft (as of 2005) at JFK Airport
John F. Kennedy International Airport
John F. Kennedy International Airport is an international airport located in the borough of Queens in New York City, about southeast of Lower Manhattan. It is the busiest international air passenger gateway to the United States, handling more international traffic than any other airport in North...
.
Emergency airplane evacuations
National Transportation Safety Board
The National Transportation Safety Board is an independent U.S. government investigative agency responsible for civil transportation accident investigation. In this role, the NTSB investigates and reports on aviation accidents and incidents, certain types of highway crashes, ship and marine...
, emergency aircraft evacuation
Emergency aircraft evacuation
Emergency aircraft evacuation refers to emergency evacuation from an aircraft which may take place on the ground, in water, or mid-flight. There are standard evacuation procedures and special evacuation equipment.-Commercial airplanes:...
s happen about once every 11 days in the U.S. While some situations are extremely dire, such as when the plane is on fire, in many cases the greatest challenge for passengers can be the use of the airplane slide
Evacuation slide
An evacuation slide is an inflatable slide used to evacuate an aircraft quickly. An escape slide is required on all commercial aircraft where the door sill height is such that, in the event of an evacuation, passengers would be unable to "step down" from the door uninjured An evacuation slide is...
. In a TIME article on the subject, Amanda Ripley reported that when a new supersized Airbus A380 underwent mandatory evacuation tests in 2006, 33 of the 873 evacuating volunteers got hurt. While the evacuation was generally considered a success, one volunteer suffered a broken leg, while the remaining 32 received slide burns. Such accidents are common. In her article, Ripley provides tips on how to make it down the airplane slide without injury.
Accidents and incidents
- List of airship accidents
- Lists of aviation accidents and incidents
- Aviation accidents and incidentsAviation accidents and incidentsAn aviation accident is defined in the Convention on International Civil Aviation Annex 13 as an occurrence associated with the operation of an aircraft which takes place between the time any person boards the aircraft with the intention of flight and all such persons have disembarked, in which a...
- Flight recorderFlight recorderA flight recorder is an electronic recording device placed in an aircraft for the purpose of facilitating the investigation of an aircraft accident or incident. For this reason, flight recorders are required to be capable of surviving the conditions likely to be encountered in a severe aircraft...
, includes flight data recorder and cockpit voice recorder
Statistics
There are three main statistics which may be used to compare the safety of various forms of travel:| Deaths per billion passenger-journeys | Deaths per billion passenger-hours | Deaths per billion passenger-kilometres |
|---|---|---|
| Bus Bus A bus is a road vehicle designed to carry passengers. Buses can have a capacity as high as 300 passengers. The most common type of bus is the single-decker bus, with larger loads carried by double-decker buses and articulated buses, and smaller loads carried by midibuses and minibuses; coaches are... : 4.3 |
Bus Bus A bus is a road vehicle designed to carry passengers. Buses can have a capacity as high as 300 passengers. The most common type of bus is the single-decker bus, with larger loads carried by double-decker buses and articulated buses, and smaller loads carried by midibuses and minibuses; coaches are... : 11.1 |
Air: 0.05 |
| Rail Rail transport Rail transport is a means of conveyance of passengers and goods by way of wheeled vehicles running on rail tracks. In contrast to road transport, where vehicles merely run on a prepared surface, rail vehicles are also directionally guided by the tracks they run on... : 20 |
Rail Rail transport Rail transport is a means of conveyance of passengers and goods by way of wheeled vehicles running on rail tracks. In contrast to road transport, where vehicles merely run on a prepared surface, rail vehicles are also directionally guided by the tracks they run on... : 30 |
Bus Bus A bus is a road vehicle designed to carry passengers. Buses can have a capacity as high as 300 passengers. The most common type of bus is the single-decker bus, with larger loads carried by double-decker buses and articulated buses, and smaller loads carried by midibuses and minibuses; coaches are... : 0.4 |
| Van Van A van is a kind of vehicle used for transporting goods or groups of people.In British English usage, it can be either specially designed or based on a saloon or sedan car, the latter type often including derivatives with open backs... : 20 |
Air: 30.8 | Rail: 0.6 |
| Car Čar Čar is a village in the municipality of Bujanovac, Serbia. According to the 2002 census, the town has a population of 296 people.-References:... : 40 |
Water Ship transport Ship transport is watercraft carrying people or goods . Sea transport has been the largest carrier of freight throughout recorded history. Although the importance of sea travel for passengers has decreased due to aviation, it is effective for short trips and pleasure cruises... : 50 |
Van Van A van is a kind of vehicle used for transporting goods or groups of people.In British English usage, it can be either specially designed or based on a saloon or sedan car, the latter type often including derivatives with open backs... : 1.2 |
| Foot Walking Walking is one of the main gaits of locomotion among legged animals, and is typically slower than running and other gaits. Walking is defined by an 'inverted pendulum' gait in which the body vaults over the stiff limb or limbs with each step... : 40 |
Van Van A van is a kind of vehicle used for transporting goods or groups of people.In British English usage, it can be either specially designed or based on a saloon or sedan car, the latter type often including derivatives with open backs... : 60 |
Water Ship transport Ship transport is watercraft carrying people or goods . Sea transport has been the largest carrier of freight throughout recorded history. Although the importance of sea travel for passengers has decreased due to aviation, it is effective for short trips and pleasure cruises... : 2.6 |
| Water Ship transport Ship transport is watercraft carrying people or goods . Sea transport has been the largest carrier of freight throughout recorded history. Although the importance of sea travel for passengers has decreased due to aviation, it is effective for short trips and pleasure cruises... : 90 |
Car Čar Čar is a village in the municipality of Bujanovac, Serbia. According to the 2002 census, the town has a population of 296 people.-References:... : 130 |
Car Čar Čar is a village in the municipality of Bujanovac, Serbia. According to the 2002 census, the town has a population of 296 people.-References:... : 3.1 |
| Air: 117 | Foot Walking Walking is one of the main gaits of locomotion among legged animals, and is typically slower than running and other gaits. Walking is defined by an 'inverted pendulum' gait in which the body vaults over the stiff limb or limbs with each step... : 220 |
Bicycle Bicycle A bicycle, also known as a bike, pushbike or cycle, is a human-powered, pedal-driven, single-track vehicle, having two wheels attached to a frame, one behind the other. A person who rides a bicycle is called a cyclist, or bicyclist.... : 44.6 |
| Bicycle Bicycle A bicycle, also known as a bike, pushbike or cycle, is a human-powered, pedal-driven, single-track vehicle, having two wheels attached to a frame, one behind the other. A person who rides a bicycle is called a cyclist, or bicyclist.... : 170 |
Bicycle Bicycle A bicycle, also known as a bike, pushbike or cycle, is a human-powered, pedal-driven, single-track vehicle, having two wheels attached to a frame, one behind the other. A person who rides a bicycle is called a cyclist, or bicyclist.... : 550 |
Foot Walking Walking is one of the main gaits of locomotion among legged animals, and is typically slower than running and other gaits. Walking is defined by an 'inverted pendulum' gait in which the body vaults over the stiff limb or limbs with each step... : 54.2 |
| Motorcycle Motorcycle A motorcycle is a single-track, two-wheeled motor vehicle. Motorcycles vary considerably depending on the task for which they are designed, such as long distance travel, navigating congested urban traffic, cruising, sport and racing, or off-road conditions.Motorcycles are one of the most... : 1640 |
Motorcycle Motorcycle A motorcycle is a single-track, two-wheeled motor vehicle. Motorcycles vary considerably depending on the task for which they are designed, such as long distance travel, navigating congested urban traffic, cruising, sport and racing, or off-road conditions.Motorcycles are one of the most... : 4840 |
Motorcycle Motorcycle A motorcycle is a single-track, two-wheeled motor vehicle. Motorcycles vary considerably depending on the task for which they are designed, such as long distance travel, navigating congested urban traffic, cruising, sport and racing, or off-road conditions.Motorcycles are one of the most... : 108.9 |
It is necessary to mention that first two statistics are computed for typical travels for respective forms of transport, so they cannot be used directly to compare risks related to different forms of transport in a particular travel "from A to B". For example: according to statistics, a typical flight from Los Angeles to New York will carry a larger risk factor than a typical car travel from home to office. But a car travel from Los Angeles to New York would not be typical. It would be as large as several dozens of typical car travels, and associated risk will be larger as well. Because the journey would take a much longer time, the overall risk associated by making this journey by car will be higher than making the same journey by air, even if each individual hour of car travel can be less risky than an hour of flight. In the same vein, when considering the "deaths per billion passenger journeys" statistic, it is important to consider that airliners, buses and trains will carry far more passengers than a car, or bicycle for example.
It is therefore important to use each statistic in a proper context. When it comes to a question about risks associated with a particular long-range travel from one city to another, the most suitable statistic is the third one, thus giving a reason to name air travel as the safest form of long-range transportation.
It is worth noting that the air industry's insurers base their calculations on the number of deaths per passenger-journey statistic while the industry itself generally uses the number of deaths per passenger-kilometre statistic in press releases.
Investigators
- Australian Transport Safety BureauAustralian Transport Safety BureauThe Australian Transport Safety Bureau is Australia’s national transport safety investigator. The ATSB is the federal government body responsible for investigating transport-related accidents and incidents within Australia. It covers air, sea and rail travel. The Australian Transport Safety...
- Flugunfalluntersuchungsstelle im BMVIT (Austria)
- Transportation Safety Board of CanadaTransportation Safety Board of CanadaThe Transportation Safety Board of Canada , officially the Canadian Transportation Accident Investigation and Safety Board is the agency of the Government of Canada responsible for maintaining...
- Air Accidents Investigation InstituteAir Accidents Investigation InstituteAir Accidents Investigation Institute is the Czech Republic government agency investigating aviation accidents and incidents. It is headquartered in Prague.-External links:* *...
(Czech Republic) - Danish Aircraft Accident Investigation Board
- Bureau d'Enquêtes et d'Analyses pour la sécurité de l'Aviation CivileBureau d'Enquêtes et d'Analyses pour la sécurité de l'Aviation CivileThe Bureau d'Enquêtes et d'Analyses pour la Sécurité de l'Aviation Civile is an agency of the French government, responsible for investigating aviation accidents and making safety recommendations based on what is learned from those investigations. It is headquartered in Building 153 on the grounds...
(France) - Bundesstelle für FlugunfalluntersuchungBundesstelle für FlugunfalluntersuchungThe German Federal Bureau of Aircraft Accidents Investigation is the German federal agency responsible for air accident investigation.The purpose of BFU is to find out the causes of air accidents and how they can be prevented. The BFU facility is located in Braunschweig, Lower Saxony...
(Germany) - Air Accident Investigation UnitAir Accident Investigation UnitThe Air Accident Investigation Unit is part of the Department of Transport, Tourism and Sport of the Republic of Ireland, and is responsible for the investigation of aircraft accidents and serious incidents within Ireland and in some cases to Irish registered aircraft elsewhere.The Air Accident...
(Ireland) - Aircraft and Railway Accidents Investigation CommissionAircraft and Railway Accidents Investigation CommissionThe was a commission belonging to the Ministry of Land, Infrastructure and Transport. Commission members are appointed by the transport minister to research causes of aircraft and railway accidents and to suggest improvements to prevent similar accidents in future...
(Japan) - Civil Aviation Authority of New ZealandCivil Aviation Authority of New ZealandThe Civil Aviation Authority of New Zealand is the government agency tasked with establishing civil aviation safety and security standards in New Zealand....
- Transport Accident Investigation CommissionTransport Accident Investigation CommissionThe Transport Accident Investigation Commission is a transport safety body of New Zealand. It has its headquarters on the 16th floor of the AXA Centre in Wellington.It was established by Act of the Parliament of New Zealand on 1 September 1990...
(New Zealand) - Comisión de Investigación de Accidentes e Incidentes de Aviación Civil (Spain)
- Swedish Accident Investigation BoardSwedish Accident Investigation BoardThe Swedish Accident Investigation Board is a Swedish government agency tasked with investigating all types of serious civil or military accidents that can occur on land, on the sea or in the air...
- Aircraft Accident Investigation BureauAircraft Accident Investigation BureauAircraft Accident Investigation Bureau is the Switzerland bureau of aircraft accident investigation. The bureau is headquartered on the grounds of Payerne Airport and in Payerne.-External links:* *...
(Switzerland) - Air Accidents Investigation BranchAir Accidents Investigation BranchThe Air Accidents Investigation Branch investigates air accidents in the United Kingdom. It is a branch of the Department for Transport and is based on the grounds of Farnborough Airport near Aldershot, Rushmoor, Hampshire.-History:...
(UK) - National Transportation Safety BoardNational Transportation Safety BoardThe National Transportation Safety Board is an independent U.S. government investigative agency responsible for civil transportation accident investigation. In this role, the NTSB investigates and reports on aviation accidents and incidents, certain types of highway crashes, ship and marine...
(USA) - European Co-ordination Center for Aircraft Incident Reporting Systems (ECCAIRS)
- International Civil Aviation Organisation
Safety Improvement Initiatives
The Safety Improvement Initiatives are aviation safety partnerships between regulators, manufacturers, operators and professional unions, research organisations, international organisations to further enhance safety.The major Safety initiatives worldwide are:
- Commercial Aviation Safety Team (CAST) in the US. The Commercial Aviation Safety Team (CAST) was founded in 1998 with a goal to reduce the commercial aviation fatality rate in the United States by 80 percent by 2007.
- European Strategic Safety Initiative (ESSI) . The European Strategic Safety Initiative (ESSI) is an aviation safety partnership between EASA, other regulators and the industry. The initiative objective is to further enhance safety for citizens in Europe and worldwide through safety analysis, implementation of cost effective action plans, and coordination with other safety initiatives worldwide.
Regulation
- Civil Aviation Authority (United KingdomUnited KingdomThe United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
) - Department of Infrastructure, Transport, Regional Development and Local Government (AustraliaAustraliaAustralia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
) - European Aviation Safety AgencyEuropean Aviation Safety AgencyThe European Aviation Safety Agency is an agency of the European Union with offices in Cologne, Germany, which has been given regulatory and executive tasks in the field of civilian aviation safety. It was created on 15 July 2002, and it reached full functionality in 2008, taking over functions...
- Federal Aviation AdministrationFederal Aviation AdministrationThe Federal Aviation Administration is the national aviation authority of the United States. An agency of the United States Department of Transportation, it has authority to regulate and oversee all aspects of civil aviation in the U.S...
(United StatesUnited StatesThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
)- Federal Aviation RegulationsFederal Aviation RegulationsThe Federal Aviation Regulations, or FARs, are rules prescribed by the Federal Aviation Administration governing all aviation activities in the United States. The FARs are part of Title 14 of the Code of Federal Regulations...
- Federal Aviation Regulations
- Irish Aviation AuthorityIrish Aviation AuthorityThe Irish Aviation Authority is a commercial semi state company employing approximately 700 people at six locations around Ireland. The IAA has two main functions; the provision of air traffic management & related services in Irish controlled airspace and the safety regulation of the civil...
- Transport CanadaTransport CanadaTransport Canada is the department within the government of Canada which is responsible for developing regulations, policies and services of transportation in Canada. It is part of the Transportation, Infrastructure and Communities portfolio...
See also
- Aerospace engineeringAerospace engineeringAerospace engineering is the primary branch of engineering concerned with the design, construction and science of aircraft and spacecraft. It is divided into two major and overlapping branches: aeronautical engineering and astronautical engineering...
- AircraftAircraftAn aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...
- Aircraft hijackingAircraft hijackingAircraft hijacking is the unlawful seizure of an aircraft by an individual or a group. In most cases, the pilot is forced to fly according to the orders of the hijackers. Occasionally, however, the hijackers have flown the aircraft themselves, such as the September 11 attacks of 2001...
- Airport securityAirport securityAirport security refers to the techniques and methods used in protecting airports and aircraft from crime.Large numbers of people pass through airports. This presents potential targets for terrorism and other forms of crime due to the number of people located in a particular location...
- AviationAviationAviation is the design, development, production, operation, and use of aircraft, especially heavier-than-air aircraft. Aviation is derived from avis, the Latin word for bird.-History:...
- Aviation archaeologyAviation archaeologyAviation archaeology is a recognized sub-discipline within archaeology and underwater archaeology as a whole. It is an activity practiced by both enthusiasts and academics in pursuit of finding, documenting, recovering, and preserving sites important in aviation history...
- Aviation historyAviation historyThe history of aviation has extended over more than two thousand years from the earliest attempts in kites and gliders to powered heavier-than-air, supersonic and hypersonic flight.The first form of man-made flying objects were kites...
- Aviation Safety NetworkAviation Safety Network-External links:**...
- Aviation Safety Reporting SystemAviation Safety Reporting SystemThe Aviation Safety Reporting System, or ASRS, is the US Federal Aviation Administration's voluntary system that allows pilots and other airplane crew members to confidentially report near misses and close calls in the interest of improving air safety...
- Charlie Victor RomeoCharlie Victor RomeoCharlie Victor Romeo is a 1999 play whose script consists of almost-verbatim transcripts from six real-life aviation accidents and incidents. "Charlie Victor Romeo," or CVR, derived from the NATO phonetic alphabet, is aviation lingo for cockpit voice recorder...
- CrashworthinessCrashworthinessCrashworthiness is the ability of a structure to protect its occupants during an impact. This is commonly tested when investigating the safety of aircraft and vehicles. Depending on the nature of the impact and the vehicle involved, different criteria are used to determine the crashworthiness of...
- Flight planningFlight planningFlight planning is the process of producing a flight plan to describe a proposed aircraft flight. It involves two safety-critical aspects: fuel calculation, to ensure that the aircraft can safely reach the destination, and compliance with air traffic control requirements, to minimise the risk of...
- Flight trainingFlight trainingFlight training is a course of study used when learning to pilot an aircraft. The overall purpose of primary and intermediate flight training is the acquisition and honing of basic airmanship skills....
- Health hazards of air travelHealth hazards of air travel-Infection:On an airplane, people sit in a confined space for extended periods of time, which increases the risk of transmission of airborne infections. For this reason, airlines place restrictions on the travel of passengers with known airborne contagious diseases...
- Hazard analysisHazard analysisA hazard analysis is used as the first step in a process used to assess risk. The result of a hazard analysis is the identification of risks. Preliminary risk levels can be provided in the hazard analysis. The validation, more precise prediction and acceptance of risk is determined in the Risk...
- Human reliabilityHuman reliabilityHuman reliability is related to the field of human factors engineering and ergonomics, and refers to the reliability of humans in fields such as manufacturing, transportation, the military, or medicine...
- IATA Operational Safety AuditIATA Operational Safety AuditThe IATA Operational Safety Audit programme is an internationally recognised and accepted evaluation system designed to assess the operational management and control systems of an airline. IOSA uses internationally recognised quality audit principles and is designed to conduct audits in a...
- Jet Airliner Crash Data Evaluation CentreJACDECJACDEC stands for the Germany's Jet Airliner Crash Data Evaluation Centre. The German authors Jan-Arwed Richter and Christian Wolf provide under that term social research as a service, detailed informations about an airline are with costs. The JACDEC Safety Index was developed from their collected...
- Lasers and aviation safetyLasers and aviation safetyUnder certain conditions, laser light or other bright lights directed at aircraft can be a hazard. The most likely scenario is when a bright visible laser light causes distraction or temporary flash blindness to a pilot, during a critical phase of flight such as landing or takeoff...
- Mid-air collisionMid-air collisionA mid-air collision is an aviation accident in which two or more aircraft come into contact during flight. Owing to the relatively high velocities involved and any subsequent impact on the ground or sea, very severe damage or the total destruction of at least one of the aircraft involved usually...
- Pilot errorPilot errorPilot error is a term used to describe the cause of an accident involving an airworthy aircraft where the pilot is considered to be principally or partially responsible...
- Road traffic safety
- Safety of emergency medical services flightsSafety of emergency medical services flightsThe safety of emergency medical services flights has become a topic of public interest in the United States, with the expansion of emergency medical services aviation operations, such as air ambulance and MEDEVAC, and the increasing frequency of related accidents.-Background:Emergency medical...
- SKYbrarySKYbrarySKYbrary is a wiki created by the European Organisation for the Safety of Air Navigation, International Civil Aviation Organization, and the Flight Safety Foundation to create a comprehensive source of aviation safety information freely available online. It was launched in May 2008 on a platform...
- Swiss cheese modelSwiss cheese modelThe Swiss cheese model is a organizational model, proposed by James Reason of the University of Manchester and Dante Orlandella, used to analyze the causes of systematic failures or accidents, commonly used in the fields of aviation, engineering and healthcare...
- Tombstone mentalityTombstone mentalityTombstone mentality is an aviation informal term that notes air safety is often improved only after somebody has died, which points out a fatal defect....
- Uncontrolled decompression
- Wind shearWind shearWind shear, sometimes referred to as windshear or wind gradient, is a difference in wind speed and direction over a relatively short distance in the atmosphere...
- Zonal Safety AnalysisZonal safety analysisZonal Safety Analysis is one of three analytical methods which, taken together, form a Common Cause Analysis in aircraft safety engineering under SAE ARP4761. The other two methods are Particular Risks Analysis and Common Mode Analysis . Aircraft system safety requires the independence of...
External links
- Safety Behaviours, a guide for pilots (comprehensive human factors information)
- NASA Aviation Safety Reporting System (ASRS)
- Airdisaster - Database of Airborne Accidents
- Latest Aviation Safety Occurrences at the Aviation Safety Network
- Aviation Safety: Advancements Being Pursued to Improve Airliner Cabin Occupant Safety and Health, 2003