1973 DeKalb-Peachtree Airport Learjet 24 crash
Encyclopedia
On February 26, 1973, a private Learjet 24
crashed shortly after take-off from DeKalb-Peachtree Airport
in Chamblee, Georgia
, United States
. The aircraft, registration
N454RN, owned by a private corporation, struck birds
shortly after lifting off. Air traffic control
advised the flight crew of smoke trailing from their left engine; the crew said they would not be able to return to the airport. The aircraft impacted the roof of an apartment building and came to rest in a ravine. All five passengers and two crew members aboard the aircraft were killed; a person in the apartment building suffered severe burns.
A subsequent investigation by the National Transportation Safety Board
(NTSB) confirmed the aircraft had impacted birds during take-off. Due to loss of power in the left engine, the flight crew were unable to control their aircraft before it struck the roof of the apartment building. The investigation further determined the Federal Aviation Administration
(FAA) and officials at DeKalb-Peachtree Airport were aware of the danger of birds at the airport after a landfill
site had opened in the vicinity of the airport ten years before the accident.
, registration N454RN, used for the flight between Chamblee, Georgia
, and Miami, Florida
, had been manufactured in 1966, and had accumulated 4,041 flying hours. Powered by two General Electric CJ610-4
turbojet engines, the aircraft was registered to Machinery Buyers Corporation, an Atlanta firm. A spokesperson for the company later told the Daily Record
the aircraft was to pick up a customer in Miami. The flight crew consisted of captain
Ernest Sellfors, aged 31, and first officer David Phillips, aged 27. Sellfors was permitted to fly Learjet 24, Learjet 23
and Hawker Siddeley 125
aircraft, and had a total of 5,600 flying hours, of which 2,150 were in jet aircraft
. Phillips had begun flying in the Learjet 24 several weeks before the accident, and had accumulated a total of 4,000 flying hours in other aircraft.
The weather around the time of the accident was overcast
, with a ceiling
of 500 feet (152.4 m). Visibility was 4 miles (6.4 km), with a 4-knot wind at 60 degrees
. At 10:10 Eastern Standard Time
, air traffic control
cleared the aircraft to take off from Runway 20L of DeKalb-Peachtree Airport
. Witnesses told the NTSB the take-off path of the aircraft appeared to be normal, but it was trailing smoke when it crossed the airport perimeter. Controllers in the air traffic control tower observed the smoke and radioed the aircraft to notify them.
Witnesses also said they heard two explosive noises, the first as the aircraft "crossed the airport boundary and the second when the aircraft was about halfway between the airport and the crash site." Although most witnesses described the smoke as white or grey, two witnesses said black smoke and flames were visible at the rear of the aircraft. According to witness statements, the aircraft climbed to a height of between 250 feet (76.2 m) and 300 feet (91.4 m), before the nose began to rise. One said the aircraft was "wobbling" and another said they thought the aircraft had stalled
. The aircraft impacted with the roof of a three-storey apartment building before it crashed into a wooded ravine
approximately 2 miles (3.2 km) from a busy highway
. All five passengers and two crew members were killed in the accident, and an individual on the ground, standing in a parking lot
, sustained serious burns from aviation fuel
and remained in a critical condition
for a day after the accident. The apartment building was damaged, and several parked vehicles destroyed.
s and empennage
had separated from the fuselage
, which had largely been consumed by fire. It was clear to investigators the aircraft had encountered a bird strike
upon take-off. One pilot who landed at around the time the Learjet took off told the Gadsden Times, "Just as we came across the runway it was almost black with birds. They swarmed and parted as we went through them."
Analysis of the cockpit area found there was bird residue and feathers on the windshield
and center post. The remains of 15 cowbird
s were found within 150 feet (45.7 m) of the end of Runway 20L. These birds, the NTSB found, had collided with the aircraft structure. Examination of the two engines found evidence of foreign objects, which consisted of minute fragments of feathers. The objects had blocked cooling ports, and had damaged the rotor assembly inside the engine. It was found the left engine had encountered 14 separate bird strikes and the right engine had encountered five. When the birds entered the engine, they caused the compressors
to stall
; these were the two loud bangs the witnesses heard as the aircraft took off. As the aircraft passed over the perimeter fence, the left engine flamed out
, and the trail of smoke was unburned fuel
passing through the hot combustion and turbine sections. Investigators determined it was possible the flight crew had managed to restart the left engine.
To pass certification, the General Electric CJ610 turbojet engine underwent bird strike testing, during which chloroform
ed birds are passed through a test engine. However, the damage to both engines was, according to the NTSB, "considerably heavier" than it had been in the test engine. Because of the failure of the left engine, and the severe damage to the right engine, the aircraft was unable to remain airborne.
came under control of the DeKalb County
government in 1960 for use as a civil airport. The County government told the FAA they would "take action to restrict the use of land adjacent to or in the immediate vicinity of the airport to activities and purposes compatible with normal airport operations including landing and take-off of aircraft." However, in the summer of 1962, ten years before the accident, a sanitary landfill
site was opened in the vicinity of the airport. The NTSB report suggests birds were regularly attracted to the landfill site.
In 1970, the FAA contacted the County government and alerted them to the potential risk of a bird strike at the airport. "In February 1971, the FAA was advised by the County that the dump would be closed by August 1972," as stated in the NTSB accident report. However, the landfill site was not closed in 1972, and remained open at the time of the accident. Investigators concluded it was likely the dump was a factor in the accident: "There is little doubt that the municipal dump located adjacent to the airport property attracts birds which are a serious hazard to aircraft."
Furthermore, the NTSB concluded the FAA had not intervened to take action with regards to the dump. "In following up on the compliance requirements for airports developed or improved with Federal funds, the FAA did not take adequate measures, in accordance with existing statues, to assure that the hazard was removed from the vicinity of the airport." The NTSB was reportedly "concerned because responsible authorities had not taken due cognizance of the bird hazards to aircraft at the DeKalb-Peachtree Airport." The final report stated,
Learjet 24
|-See also:-References:* Taylor, John W. R. Jane's All The World's Aircraft 1976–77. London:Jane's Yearbooks, 1976. ISBN 0-354-00538-3.-External links:**...
crashed shortly after take-off from DeKalb-Peachtree Airport
DeKalb-Peachtree Airport
DeKalb-Peachtree Airport is a municipal general aviation airport located in Chamblee, Georgia, just northeast of Atlanta. It is operated by the local government of DeKalb County, Georgia, and is also known commonly as Peachtree-DeKalb Airport, or simply PDK. Other names include Peachtree...
in Chamblee, Georgia
Georgia (U.S. state)
Georgia is a state located in the southeastern United States. It was established in 1732, the last of the original Thirteen Colonies. The state is named after King George II of Great Britain. Georgia was the fourth state to ratify the United States Constitution, on January 2, 1788...
, United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
. The aircraft, registration
Aircraft registration
An aircraft registration is a unique alphanumeric string that identifies a civil aircraft, in similar fashion to a licence plate on an automobile...
N454RN, owned by a private corporation, struck birds
Bird strike
A bird strike—sometimes called birdstrike, avian ingestion , bird hit, or BASH —is a collision between an airborne animal and a man-made vehicle, especially aircraft...
shortly after lifting off. 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...
advised the flight crew of smoke trailing from their left engine; the crew said they would not be able to return to the airport. The aircraft impacted the roof of an apartment building and came to rest in a ravine. All five passengers and two crew members aboard the aircraft were killed; a person in the apartment building suffered severe burns.
A subsequent investigation by 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...
(NTSB) confirmed the aircraft had impacted birds during take-off. Due to loss of power in the left engine, the flight crew were unable to control their aircraft before it struck the roof of the apartment building. The investigation further determined the Federal Aviation Administration
Federal Aviation Administration
The 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...
(FAA) and officials at DeKalb-Peachtree Airport were aware of the danger of birds at the airport after a landfill
Landfill
A landfill site , is a site for the disposal of waste materials by burial and is the oldest form of waste treatment...
site had opened in the vicinity of the airport ten years before the accident.
Accident
The Learjet 24Learjet 24
|-See also:-References:* Taylor, John W. R. Jane's All The World's Aircraft 1976–77. London:Jane's Yearbooks, 1976. ISBN 0-354-00538-3.-External links:**...
, registration N454RN, used for the flight between Chamblee, Georgia
Georgia (U.S. state)
Georgia is a state located in the southeastern United States. It was established in 1732, the last of the original Thirteen Colonies. The state is named after King George II of Great Britain. Georgia was the fourth state to ratify the United States Constitution, on January 2, 1788...
, and Miami, 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...
, had been manufactured in 1966, and had accumulated 4,041 flying hours. Powered by two General Electric CJ610-4
General Electric CJ610
|-See also:-External links:*...
turbojet engines, the aircraft was registered to Machinery Buyers Corporation, an Atlanta firm. A spokesperson for the company later told the Daily Record
Daily Record (Washington)
The Daily Record is an American daily newspaper published in Ellensburg, Washington. The Record is published six days a week with an afternoon edition each Monday through Friday with a weekend edition delivered on Saturday mornings...
the aircraft was to pick up a customer in Miami. The flight crew consisted of captain
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...
Ernest Sellfors, aged 31, and first officer David Phillips, aged 27. Sellfors was permitted to fly Learjet 24, Learjet 23
Learjet 23
-References:* Taylor, John W. R. Jane's All The World's Aircraft 1965–1966. London:Sampson Low, Marston & Company, 1965.**-External links:*...
and Hawker Siddeley 125
British Aerospace BAe 125
The British Aerospace 125 is a twin-engined mid-size corporate jet, with newer variants now marketed as the Hawker 800. It was known as the Hawker Siddeley HS.125 until 1977...
aircraft, and had a total of 5,600 flying hours, of which 2,150 were in jet aircraft
Jet aircraft
A jet aircraft is an aircraft propelled by jet engines. Jet aircraft generally fly much faster than propeller-powered aircraft and at higher altitudes – as high as . At these altitudes, jet engines achieve maximum efficiency over long distances. The engines in propeller-powered aircraft...
. Phillips had begun flying in the Learjet 24 several weeks before the accident, and had accumulated a total of 4,000 flying hours in other aircraft.
The weather around the time of the accident was overcast
Overcast
Overcast or overcast weather, as defined by the World Meteorological Organization, is the meteorological condition of clouds obscuring all of the sky. Overcast, written as "OVC" in the METAR observation, is reported when the cloud cover is observed to equal eight oktas .Sometimes clouds can be...
, with a ceiling
Ceiling (aeronautics)
With respect to aircraft, a ceiling is the maximum density altitude an aircraft can reach under a set of conditions.The word ceiling can also refer to the height of the lowest obscuring cloud layer above the ground.-Service ceiling:...
of 500 feet (152.4 m). Visibility was 4 miles (6.4 km), with a 4-knot wind at 60 degrees
Degree (angle)
A degree , usually denoted by ° , is a measurement of plane angle, representing 1⁄360 of a full rotation; one degree is equivalent to π/180 radians...
. At 10:10 Eastern Standard Time
Eastern Standard Time
Eastern Standard Time may refer to:*North American Eastern Time Zone, UTC-5*Australian Eastern Standard Time, UTC+10*An album by Hip Hop group Kooley High...
, 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...
cleared the aircraft to take off from Runway 20L of DeKalb-Peachtree Airport
DeKalb-Peachtree Airport
DeKalb-Peachtree Airport is a municipal general aviation airport located in Chamblee, Georgia, just northeast of Atlanta. It is operated by the local government of DeKalb County, Georgia, and is also known commonly as Peachtree-DeKalb Airport, or simply PDK. Other names include Peachtree...
. Witnesses told the NTSB the take-off path of the aircraft appeared to be normal, but it was trailing smoke when it crossed the airport perimeter. Controllers in the air traffic control tower observed the smoke and radioed the aircraft to notify them.
| Tower: | Lear 454RN it appeared the left engine laid a pretty good layer of smoke out of the left side there for approximately 300 or 400 feet. |
| N454RN: | We just hit some birds. |
| Tower: | Roger, [are] you returning to land? |
| N454RN: | Don't believe we're gonna make it. |
Witnesses also said they heard two explosive noises, the first as the aircraft "crossed the airport boundary and the second when the aircraft was about halfway between the airport and the crash site." Although most witnesses described the smoke as white or grey, two witnesses said black smoke and flames were visible at the rear of the aircraft. According to witness statements, the aircraft climbed to a height of between 250 feet (76.2 m) and 300 feet (91.4 m), before the nose began to rise. One said the aircraft was "wobbling" and another said they thought the aircraft had stalled
Stall (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...
. The aircraft impacted with the roof of a three-storey apartment building before it crashed into a wooded ravine
Ravine
A ravine is a landform narrower than a canyon and is often the product of streamcutting erosion. Ravines are typically classified as larger in scale than gullies, although smaller than valleys. A ravine is generally a fluvial slope landform of relatively steep sides, on the order of twenty to...
approximately 2 miles (3.2 km) from a busy highway
Highway
A highway is any public road. In American English, the term is common and almost always designates major roads. In British English, the term designates any road open to the public. Any interconnected set of highways can be variously referred to as a "highway system", a "highway network", or a...
. All five passengers and two crew members were killed in the accident, and an individual on the ground, standing in a parking lot
Parking lot
A parking lot , also known as car lot, is a cleared area that is intended for parking vehicles. Usually, the term refers to a dedicated area that has been provided with a durable or semi-durable surface....
, sustained serious burns from aviation fuel
Aviation fuel
Aviation fuel is a specialized type of petroleum-based fuel used to power aircraft. It is generally of a higher quality than fuels used in less critical applications, such as heating or road transport, and often contains additives to reduce the risk of icing or explosion due to high temperatures,...
and remained in a critical condition
Critical Condition
Critical condition is a medical state.Critical Condition may also be:* Critical Condition , an episode of the television series Sex and the City* Critical Condition , a 1987 comedy film...
for a day after the accident. The apartment building was damaged, and several parked vehicles destroyed.
Bird strikes
Upon reaching the accident site, investigators from the NTSB found both engines, the wingWing
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 and 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...
had separated from the fuselage
Fuselage
The fuselage is an aircraft's main body section that holds crew and passengers or cargo. In single-engine aircraft it will usually contain an engine, although in some amphibious aircraft the single engine is mounted on a pylon attached to the fuselage which in turn is used as a floating hull...
, which had largely been consumed by fire. It was clear to investigators the aircraft had encountered a bird strike
Bird strike
A bird strike—sometimes called birdstrike, avian ingestion , bird hit, or BASH —is a collision between an airborne animal and a man-made vehicle, especially aircraft...
upon take-off. One pilot who landed at around the time the Learjet took off told the Gadsden Times, "Just as we came across the runway it was almost black with birds. They swarmed and parted as we went through them."
Analysis of the cockpit area found there was bird residue and feathers on the windshield
Windshield
The windshield or windscreen of an aircraft, car, bus, motorbike or tram is the front window. Modern windshields are generally made of laminated safety glass, a type of treated glass, which consists of two curved sheets of glass with a plastic layer laminated between them for safety, and are glued...
and center post. The remains of 15 cowbird
Cowbird
Cowbirds are birds belonging to the genus Molothrus in the family Icteridae. They are brood parasitic New World birds which are unrelated to the Old World cuckoos, one of which, the Common Cuckoo, is the best-known brood parasitic bird....
s were found within 150 feet (45.7 m) of the end of Runway 20L. These birds, the NTSB found, had collided with the aircraft structure. Examination of the two engines found evidence of foreign objects, which consisted of minute fragments of feathers. The objects had blocked cooling ports, and had damaged the rotor assembly inside the engine. It was found the left engine had encountered 14 separate bird strikes and the right engine had encountered five. When the birds entered the engine, they caused the compressors
Jet engine compressors
As the name suggests, Jet engine compressors provide the compression part of the jet engine thermodynamic cycle.There are three basic categories of jet engine compressor:#Axial compressor#Centrifugal compressor#Mixed flow compressor...
to stall
Compressor stall
A compressor stall is a situation of abnormal airflow resulting from a stall of the aerofoils within the compressor of a jet engine. Stall is found in dynamic compressors, particularly axial compressors, as used in jet engines and turbochargers for reciprocating engines.Compressor stalls result in...
; these were the two loud bangs the witnesses heard as the aircraft took off. As the aircraft passed over the perimeter fence, the left engine flamed out
Flameout
A flameout refers to the failure of a jet engine caused by the extinction of the flame in the combustion chamber. It can be caused by a number of factors, including fuel exhaustion; compressor stall; insufficient oxygen supply; foreign object damage ; severe inclement weather; and mechanical...
, and the trail of smoke was unburned fuel
Aviation fuel
Aviation fuel is a specialized type of petroleum-based fuel used to power aircraft. It is generally of a higher quality than fuels used in less critical applications, such as heating or road transport, and often contains additives to reduce the risk of icing or explosion due to high temperatures,...
passing through the hot combustion and turbine sections. Investigators determined it was possible the flight crew had managed to restart the left engine.
To pass certification, the General Electric CJ610 turbojet engine underwent bird strike testing, during which chloroform
Chloroform
Chloroform is an organic compound with formula CHCl3. It is one of the four chloromethanes. The colorless, sweet-smelling, dense liquid is a trihalomethane, and is considered somewhat hazardous...
ed birds are passed through a test engine. However, the damage to both engines was, according to the NTSB, "considerably heavier" than it had been in the test engine. Because of the failure of the left engine, and the severe damage to the right engine, the aircraft was unable to remain airborne.
The airport
Formerly a military base, DeKalb-Peachtree AirportDeKalb-Peachtree Airport
DeKalb-Peachtree Airport is a municipal general aviation airport located in Chamblee, Georgia, just northeast of Atlanta. It is operated by the local government of DeKalb County, Georgia, and is also known commonly as Peachtree-DeKalb Airport, or simply PDK. Other names include Peachtree...
came under control of the DeKalb County
DeKalb County, Georgia
DeKalb County is a county located in the U.S. state of Georgia. The population of the county was 691,893 at the 2010 census. Its county seat is the city of Decatur. It is bordered to the west by Fulton County and contains roughly 10% of the city of Atlanta...
government in 1960 for use as a civil airport. The County government told the FAA they would "take action to restrict the use of land adjacent to or in the immediate vicinity of the airport to activities and purposes compatible with normal airport operations including landing and take-off of aircraft." However, in the summer of 1962, ten years before the accident, a sanitary landfill
Landfill
A landfill site , is a site for the disposal of waste materials by burial and is the oldest form of waste treatment...
site was opened in the vicinity of the airport. The NTSB report suggests birds were regularly attracted to the landfill site.
In 1970, the FAA contacted the County government and alerted them to the potential risk of a bird strike at the airport. "In February 1971, the FAA was advised by the County that the dump would be closed by August 1972," as stated in the NTSB accident report. However, the landfill site was not closed in 1972, and remained open at the time of the accident. Investigators concluded it was likely the dump was a factor in the accident: "There is little doubt that the municipal dump located adjacent to the airport property attracts birds which are a serious hazard to aircraft."
Furthermore, the NTSB concluded the FAA had not intervened to take action with regards to the dump. "In following up on the compliance requirements for airports developed or improved with Federal funds, the FAA did not take adequate measures, in accordance with existing statues, to assure that the hazard was removed from the vicinity of the airport." The NTSB was reportedly "concerned because responsible authorities had not taken due cognizance of the bird hazards to aircraft at the DeKalb-Peachtree Airport." The final report stated,
Conclusions
The final NTSB accident report concluded the probable cause of the accident was the loss of power due to a bird strike to both engines. The risk of bird strikes was, the Board found, magnified by the landfill site located adjacent to the airport. The FAA and airport authorities were both aware of the danger, and did not act on the information. The final report stated,Recommendations
In the aftermath of the accident, the NTSB made several recommendations. They recommended the FAA "develop and implement a procedure for more stringent and continued surveillance" of airports which develop properties adjacent to the flight paths of aircraft, and "impose timely sanctions against operators of facilities which receive Federal aid and do not fully comply with the requirements imposed upon them." They also advised the FAA to circulate material around airports warning authorities of the dangers posed by landfill sites in the vicinity of runways.See also
- Air safetyAir safetyAir 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.-United...
- List of accidents and incidents involving commercial aircraft
- 1973 in aviation1973 in aviationThis is a list of aviation-related events from 1973:- Events :*Don Taylor attempts round-the-world trip in his homebuilt Thorp T-18, ended by a spate of really bad weather between northern Japan and the Aleutian Islands. His next attempt in the summer of 1976 is successful.-January:* U.S...