Harriman State Park plane crash
Encyclopedia
The Harriman State Park plane crash was a fatal crash of a Boeing 727
which took place on December 1, 1974 near Stony Point, New York
. The flight, designated Northwest Airlines
flight 6231, had been chartered to pick up the Baltimore Colts
football team in Buffalo, New York
. All three crew members aboard were killed when the aircraft struck the ground following a stall
and rapid descent caused by the crew's reaction to erroneous airspeed
readings caused by atmospheric icing
. The icing occurred due to failure to turn on pitot heat at the beginning of the flight.
football team in Buffalo, New York after the aircraft for the team's originally chartered flight was grounded by a snowstorm in Detroit.
The Northwest Airlines
Boeing 727-251, tail number N274US, departed John F. Kennedy International Airport
at 19:14 for a ferry flight to Buffalo. As the craft climbed past 16,000 feet, the overspeed warning horn sounded, followed 10 seconds later by a stick shaker
stall warning. The aircraft leveled at 24,800 feet until it started to descend out of control in a spin
, reaching a vertical acceleration of +5g until it struck the ground in a slightly nose down and right wing-down attitude at 19:26. The aircraft had descended from 24000 feet to 1090 feet in 83 seconds.
led the accident investigation and released its final report on August 13, 1975. Parties to the investigation included the Federal Aviation Administration
, Northwest Airlines, The Boeing Company
, Air Line Pilots Association
, International Association of Machinists and Aerospace Workers
, and Pratt & Whitney
.
Investigators found that the pitot
heads had ice
damage which caused the crew to receive the wrong readings. The crew, believing the readings were true, raised their nose and pulled back on the control column, which caused the plane to stall.
From the NTSB report's abstract:
When investigators found the 727's voice recorder, the recording revealed that the pilots believed that the shaking of the stick shaker
mechanism was caused by the plane reaching the speed of sound
, and not a warning that the plane was going into a stall.
In that manner, this crash resembles the one of Air France Flight 447
(June 1st, 2009), where the pilots were warned of unreliable airspeed, but failed to perform the necessary procedures.
Tail section of a similar 727.
Boeing 727
The Boeing 727 is a mid-size, narrow-body, three-engine, T-tailed commercial jet airliner, manufactured by Boeing. The Boeing 727 first flew in 1963, and for over a decade more were built per year than any other jet airliner. When production ended in 1984 a total of 1,832 aircraft had been produced...
which took place on December 1, 1974 near Stony Point, New York
Stony Point, New York
Stony Point is a triangle-shaped town in Rockland County, United States. Rockland County is part of the New York Metropolitan Area. The town is located north of the town of Haverstraw, east and south of Orange County, New York, and west of the Hudson River and Westchester County. The population...
. The flight, designated 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...
flight 6231, had been chartered to pick up the Baltimore Colts
Indianapolis Colts
The Indianapolis Colts are a professional American football team based in Indianapolis. They are currently members of the South Division of the American Football Conference in the National Football League ....
football team in Buffalo, New York
Buffalo, New York
Buffalo is the second most populous city in the state of New York, after New York City. Located in Western New York on the eastern shores of Lake Erie and at the head of the Niagara River across from Fort Erie, Ontario, Buffalo is the seat of Erie County and the principal city of the...
. All three crew members aboard were killed when the aircraft struck the ground following a stall
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...
and rapid descent caused by the crew's reaction to erroneous airspeed
Airspeed
Airspeed is the speed of an aircraft relative to the air. Among the common conventions for qualifying airspeed are: indicated airspeed , calibrated airspeed , true airspeed , equivalent airspeed and density airspeed....
readings caused by atmospheric 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...
. The icing occurred due to failure to turn on pitot heat at the beginning of the flight.
Accident
The flight was chartered to pick up the Baltimore ColtsIndianapolis Colts
The Indianapolis Colts are a professional American football team based in Indianapolis. They are currently members of the South Division of the American Football Conference in the National Football League ....
football team in Buffalo, New York after the aircraft for the team's originally chartered flight was grounded by a snowstorm in Detroit.
The 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...
Boeing 727-251, tail number N274US, departed John F. Kennedy International 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...
at 19:14 for a ferry flight to Buffalo. As the craft climbed past 16,000 feet, the overspeed warning horn sounded, followed 10 seconds later by a 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...
stall warning. The aircraft leveled at 24,800 feet until it started to descend out of control in a spin
Spin (flight)
In aviation, a spin is an aggravated stall resulting in autorotation about the spin axis wherein the aircraft follows a corkscrew downward path. Spins can be entered intentionally or unintentionally, from any flight attitude and from practically any airspeed—all that is required is sufficient yaw...
, reaching a vertical acceleration of +5g until it struck the ground in a slightly nose down and right wing-down attitude at 19:26. The aircraft had descended from 24000 feet to 1090 feet in 83 seconds.
Crew
The plane had three crewmembers aboard. The pilot, Capt. John B. Lagario, had worked for Northwest for eight years. First officer Walter A. Zadra and second officer James F. Cox Jr. had each been with the airline for six years.Aftermath
The crash site was located the day after the accident. Police described the site as a heavily wooded marshy area and accessibility was hampered by winter weather conditions including wind and a rain-snow mix.Investigation
The National Transportation Safety BoardNational 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...
led the accident investigation and released its final report on August 13, 1975. Parties to the investigation included 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...
, Northwest Airlines, The Boeing Company
Boeing
The Boeing Company is an American multinational aerospace and defense corporation, founded in 1916 by William E. Boeing in Seattle, Washington. Boeing has expanded over the years, merging with McDonnell Douglas in 1997. Boeing Corporate headquarters has been in Chicago, Illinois since 2001...
, Air Line Pilots Association
Air Line Pilots Association, International
The Air Line Pilots Association, International , is the collective bargaining representative for over 59,000 pilots of 39 U.S. and Canadian airlines. ALPA was formed in 1931 and is a member of the AFL-CIO and the Canadian Labour Congress...
, International Association of Machinists and Aerospace Workers
International Association of Machinists and Aerospace Workers
The International Association of Machinists and Aerospace Workers is an AFL-CIO/CLC trade union representing approx. 646,933 workers as of 2006 in more than 200 industries.-Formation and early history:...
, and Pratt & Whitney
Pratt & Whitney
Pratt & Whitney is a U.S.-based aerospace manufacturer with global service operations. It is a subsidiary of United Technologies Corporation . Pratt & Whitney's aircraft engines are widely used in both civil aviation and military aviation. Its headquarters are in East Hartford, Connecticut, USA...
.
Investigators found that the pitot
Pitot tube
A pitot tube is a pressure measurement instrument used to measure fluid flow velocity. The pitot tube was invented by the French engineer Henri Pitot Ulo in the early 18th century and was modified to its modern form in the mid-19th century by French scientist Henry Darcy...
heads had ice
Ice
Ice is water frozen into the solid state. Usually ice is the phase known as ice Ih, which is the most abundant of the varying solid phases on the Earth's surface. It can appear transparent or opaque bluish-white color, depending on the presence of impurities or air inclusions...
damage which caused the crew to receive the wrong readings. The crew, believing the readings were true, raised their nose and pulled back on the control column, which caused the plane to stall.
From the NTSB report's abstract:
...the probable cause of this accident was the loss of control of the aircraft because the flightcrew failed to recognize and correct the aircraft's high angle of attackAngle of attackAngle 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...
, low-speed stallStallIn 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...
and its descending spiral. The stall was precipitated by the flightcrew's improper reaction to erroneous airspeed and MachMach numberMach number is the speed of an object moving through air, or any other fluid substance, divided by the speed of sound as it is in that substance for its particular physical conditions, including those of temperature and pressure...
indications which had resulted from a blockage of the pitot heads by atmospheric icing.
When investigators found the 727's voice recorder, the recording revealed that the pilots believed that the shaking of the 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...
mechanism was caused by the plane reaching the speed of sound
Speed of sound
The speed of sound is the distance travelled during a unit of time by a sound wave propagating through an elastic medium. In dry air at , the speed of sound is . This is , or about one kilometer in three seconds or approximately one mile in five seconds....
, and not a warning that the plane was going into a stall.
In that manner, this crash resembles the one of Air France Flight 447
Air France Flight 447
Air France Flight 447 was a scheduled airline flight from Rio de Janeiro-Galeão to Paris-Roissy involving an Airbus A330-200 aircraft that crashed into the Atlantic Ocean on 1 June 2009, killing all 216 passengers and 12 aircrew. The investigation is still ongoing, and the cause of the...
(June 1st, 2009), where the pilots were warned of unreliable airspeed, but failed to perform the necessary procedures.
Photos
An example of a Pitot tube which froze on this flight.Tail section of a similar 727.
See also
- Air France Flight 447Air France Flight 447Air France Flight 447 was a scheduled airline flight from Rio de Janeiro-Galeão to Paris-Roissy involving an Airbus A330-200 aircraft that crashed into the Atlantic Ocean on 1 June 2009, killing all 216 passengers and 12 aircrew. The investigation is still ongoing, and the cause of the...
, which is also believed to have crashed due to the pitot tubes freezing
External links
- Final Accident Report - 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...