Controlled flight into terrain

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"CFIT" redirects here. For the IQ test, see Cattell Culture Fair III. For the Canadian radio station, see CFIT-FM.
A piece of the 25 year old remains of Air New Zealand Flight 901, which impacted Mount Erebus in 1979. All 257 people on the plane were killed making it the fourth largest loss of life in a single crash when it occurred.[1]

Controlled flight into terrain (CFIT) describes an accident in which an airworthy aircraft, under pilot control, is unintentionally flown into the ground, a mountain, water, or an obstacle.[2] The pilots are generally unaware of the danger until it is too late. The term was coined by engineers at Boeing in the late 1970s.[3] Accidents where an aircraft is already damaged and uncontrollable at the time of the collision (also known as uncontrolled flight into terrain) are not considered CFIT.

According to Boeing, CFIT is a leading cause of airplane accidents involving the loss of life, causing over 9,000 deaths since the beginning of the commercial jet age.[4] CFIT was identified as a cause of 25% of USAF Class A Mishaps between 1993 and 2002.[5]


Animation of the descent of Korean Air Flight 801 in Guam in 1997 (NTSB)

While there are many reasons why a plane might crash into terrain, including bad weather and navigation equipment problems, pilot error is the most common factor found in CFIT accidents.[2]

And, the most common type of pilot error in CFIT accidents, is the failure of the pilot(s) to know at all times what their position is, and how their actual position relates to the altitude of the surface of the Earth below and immediately ahead, on the course they are flying (a loss of situational awareness). Fatigue can cause even highly experienced professionals to make significant errors, which culminate in a CFIT accident.[6]

CFIT accidents frequently involve a collision with terrain such as hills or mountains during conditions of reduced visibility, while conducting an approach to landing at the destination airport. Sometimes, a contributing factor can be subtle navigation equipment malfunctions which, if not detected by the crew, may mislead them into improperly guiding the aircraft, despite other information received from properly functioning equipment.


Prior to the installation of the first electronic warning systems, pilot simulator training, traditional procedures, crew resource management (CRM) and radar surveillance by air traffic services were the only defenses against CFIT. While those factors undoubtedly reduced the total amount of CFIT accidents, they did not eliminate them entirely. To prevent the continued occurrence of CFIT accidents, manufacturers developed terrain awareness and warning systems (TAWS). The first generation of those systems was known as a ground proximity warning system (GPWS), which used a radar altimeter to assist in calculating terrain closure rates. That system was further improved with the addition of a GPS terrain database and is now known as an enhanced ground proximity warning system (EGPWS). When combined with mandatory pilot simulator training, which emphasizes proper responses to any caution or warning event, the system has proved very effective in preventing further CFIT accidents.[7]

Smaller aircraft often use a GPS database of terrain to provide terrain warning. The GPS database contains a database of nearby terrain and will present terrain that is near the aircraft in red or yellow depending on its distance from the aircraft.[8]

Statistics show that aircraft fitted with a second-generation EGPWS have not suffered a CFIT accident[9] if TAWS or EGPWS are properly handled (there are at least two CFIT accidents of planes with EGPWS/TAWS: 2010 Polish Air Force Tu-154 crash and the Mirosławiec air accident). As of 2007, 5% of the world's commercial airlines still lack a TAWS, leading to a prediction of two CFIT accidents in 2009.[9] In the case of Mount Salak Sukhoi Superjet 100 crash, the TAWS was working but the pilot intentionally turned it off.[10]

Notable accidents[edit]

Many notable accidents have been ascribed to CFIT.

TWA Flight 3January 16, 1942Fifteen minutes after takeoff from Las Vegas, the plane hit a sheer cliff on Potosi Mountain, 32 miles from the airport, at an elevation of 7,770 ft. No survivors among the 19 passengers and 3 crew on board, including movie star Carole Lombard and her mother. Cause was the deviation from the safe airway route, during a nighttime flight.
BSAA Star DustAugust 2, 1947Due to a misjudgment of position, the flight crew appear to have believed that the aircraft was approaching the airport of Santiago, when in fact it was still above Tupungato mountain in the Andes. The plane vanished shortly after its last transmission estimating the time of its arrival at Santiago. Its wreckage was discovered fifty years later.
Superga air disasterMay 4, 1949Collision with the hill of Superga, near Turin.
Pan Am Flight 151June 21, 1951Collision with hill, Liberia, Africa
United Airlines Flight 610June 30, 1951Crashed into Crystal Mountain, CO, after failing to make a required left turn, to remain on the flight planned course to Denver.
British Commonwealth Pacific Airlines Flight 304October 29, 1953Premature descent while intercepting ILS for SFO airport
TWA Flight 260February 19, 1955Crashed into Sandia Mountains, near Albuquerque, NM, while in instrument flight conditions. Suspected failure of a critical navigation instrument.
United Airlines Flight 409October 6, 1955Unexplained deviation from flight plan course; hit Medicine Bow Peak, CO
Trans-Canada Air Lines Flight 810December 9, 1956
1958 Bristol Britannia 312 crashDecember 24, 1958
American Airlines Flight 320February 3, 1959
Piedmont Airlines Flight 349October 30, 1959
TAA Fokker Friendship disasterJune 10, 1960
Alitalia Flight 771July 7, 1962
Aero Flight 217November 8, 1963DC-3. Crashed into a knoll on landing approach at Mariehamn, Finland. The root cause was a malfunctioning altimeter.
United Airlines Flight 389August 16, 1965
American Airlines Flight 383November 8, 1965
TABSO Flight 101November 24, 1966Crashed Bratislava, Slovakia, killing all 82 on board
Iberia Airlines Flight 062November 4, 1967
TWA Flight 128November 20, 1967Crashed short of the runway, after descending below the minimum descent altitude (MDA), in non-visual conditions, while conducting a non-precision approach to the Cincinnati airport.
South African Airways Flight 228April 20, 1968Failure by crew to maintain a safe airspeed and altitude and a positive climb by not observing flight instruments during take-off.
Southern Airways Flight 932November 14, 1970Crashed near Huntington, West Virginia, killing all 75 on board
Alaska Airlines Flight 1866September 4, 1971Flew into the side of a canyon on approach to Juneau, Alaska. 111 fatalities (104 passengers, 7 crew)
Uruguayan Air Force Flight 571October 13, 1972Known less formally as the Andes flight disaster, October 13, 1972 to December 23, 1972, during which stranded snow-bound survivors resorted to cannibalism. The incident became the subject of feature films and best-selling books.
Braathens SAFE Flight 239December 23, 1972
Eastern Air Lines Flight 401December 29, 1972The cockpit crew became fixated on a faulty landing gear light and had failed to realize that the autopilot had been switched off. The distracted crew did not recognize the plane's slow descent and the otherwise completely airworthy aircraft struck swampy ground in the Everglades, killing 101 out of 176 passengers and crew. This accident became the subject of books and made-for-television movies.
Delta Air Lines Flight 723July 31, 1973
TWA Flight 514December 1, 1974
Turkish Airlines Flight 452September 19, 1976Crashed into a hill 60 miles off the destination airport killing all 154 people on board.
Air New Zealand Flight 901November 28, 1979Crashed into Mount Erebus, Antarctica on November 28, 1979. There is still disagreement over the exact causes of the crash, but it is commonly accepted that a changing of pre-programmed coordinates without informing the pilots, the pilots' loss of situational awareness and whiteout conditions at the time were contributory factors leading to the crash. All 257 people on the plane were killed.
Dan-Air Flight 1008April 25, 1980Crashed into high terrain in Tenerife after turning the wrong way in a holding pattern. All 146 people aboard were killed.
Inex-Adria Aviopromet Flight 1308December 1, 1981Struck Corsica's Mt. San Pietro and crashed shortly before it was scheduled to land. All 180 people on board were killed.
VASP Flight 168June 8, 1982Highest death toll of aviation accidents in Brazil for 24 years.
Avianca Flight 011November 27, 1983
1984 Biman Bangladesh Airlines Fokker F27 crashAugust 5, 1984Worst air disaster in history of Bangladeshi aviation.[11][12]
Eastern Air Lines Flight 980January 1, 1985Struck Mount Illimani in Bolivia at an altitude of 19,600 feet. The flight took off from Silvio Pettirossi International Airport in Asunción, Paraguay, and intended to reach El Alto International Airport in La Paz, Bolivia. All 19 passengers and 10 crew were killed on impact.
1986 Mozambican Tupolev Tu-134 crashOctober 19, 1986President Machel of Mozambique and 33 others die when their off course plane descends and flies into the Lebombo Mountains.
Avianca Flight 410March 17, 1988
Air France Flight 296June 26, 1988Crashed into trees while performing a flyover for an airshow at Mulhouse-Habsheim Airport. Out of 130 passengers and six crew members, three passengers died in the post-impact fire.
Indian Airlines Flight 113October 19, 1988The aircraft hit an electric mast in Ahmedabad, India, five miles (eight km) out on approach in poor visibility. All six crew members and 124 of 129 passengers were killed.
Independent Air Flight 1851February 8, 1989
Flying Tiger Line Flight 66February 19, 1989
Flying Tigers 747
The aircraft was on an international cargo flight from Singapore to Kuala Lumpur, Malaysia, and crashed shortly before landing. The crew descended below approach altitude and crashed into a hill. All four crew members were killed.
Surinam Airways Flight 764June 7, 1989
Indian Airlines Flight 605February 14, 1990Crashed short of the runway during final approach to Bangalore, killing 92 on board.
Death of Stevie Ray Vaughan, East Troy, WisconsinAugust 27, 1990Bell 206B Jet Ranger helicopter flown into the side of a hill in heavy fog.
Alitalia Flight 404, ZurichNovember 14, 1990DC-9-32 flown into side of mountain on landing approach due to defective ILS gear, killing all 40 passengers and 6 crew. Lack of proper crew resource management has been identified as contributing cause.
Air Inter Flight 148January 20, 1992Crashed into Mt. Ste. Odile in the Vosges Mountains whilst on approach into Strasbourg Entzheim Airport.
Thai Airways International Flight 311July 31, 1992Crashed on approach to Kathmandu. All 113 people on board were killed, 59 days before the PIA Flight 268 accident at Kathmandu.
PIA Flight 268September 28, 1992
Wreckage Of PIA Flight 268.
Crashed on approach to Kathmandu. The approach to Kathmandu is difficult, as the airport is located in an oval-shaped valley surrounded by mountains. Flight 268 was approximately 900 feet below the designated approach path and crashed into a steep cloud-covered hillside. All 167 people on the plane were killed.
SAM Colombia Flight 501May 19, 1993Crashed near Mt. Panamo Frontino, killing all 132 people on board the Boeing 727-100
Asiana Airlines Flight 733July 26, 1993While approaching in bad weather, a Boeing 737-500 crashed into a mountain near Mokpo, South Korea. 68 of 106 on board were killed.
Ansett New Zealand Flight 703June 5, 1995
American Airlines Flight 1572November 12, 1995
American Airlines Flight 965December 20, 1995Crashed into a mountain near Buga, Colombia. The crew failed to recognize a series of navigational errors they had made, and forgot that they had deployed the air brakes. All eight crew members and 151 of the 155 passengers were killed.
1996 Croatia USAF CT-43 crashApril 3, 1996A modified Boeing 737 crashed into a mountain in Croatia.
Vnukovo Flight 2801August 29, 1996All 141 people aboard a Tupolev Tu-154M were killed, when the aircraft crashed into Operafjellet during approach to Svalbard Airport, Longyear, Svalbard, Norway. This airport does not provide any approach service.
1996 New Hampshire Learjet crashDecember 24, 1996Found November 13, 1999
Korean Air Flight 801August 6, 1997A Boeing 747-300 crashed into Nimitz Hill on approach to Guam, killing 228 of 254 people aboard. The fatigued crew were following outdated flight maps, while ATC had modified its MSAW system to eliminate false alarms.
Garuda Indonesia Flight 152September 26, 1997An Airbus A300, registered PK-GAI, crashed in Pancur Batu, Pematang Siantar, North Sumatera, becoming the worst air disaster in Indonesian aviation history.
Kenya Airways Flight 431January 30, 2000Impacted ocean after takeoff from Félix Houphouët-Boigny International Airport, killing all 10 crew and 159 out of 169 passengers. The pilots put the plane into a descent in response to an erroneous stall warning.
Air Philippines Flight 541April 19, 2000Crashed in Island Garden City of Samal, Davao del Norte, killing all 131 people on board. It is also currently the deadliest air disaster in the Philippines.
Crossair Flight 3597November 24, 2001Flight from Berlin to Zurich that crashed during its landing approach, killing 24 people.
Air China Flight 129April 15, 2002
Kam Air Flight 904February 3, 2005
2006 Slovak Air Force Antonov An-24 crashJanuary 19, 2006
Armavia Flight 967May 3, 2006
Atlasjet Flight 4203November 30, 2007
Santa Bárbara Airlines Flight 518February 21, 2008
2010 Polish Air Force Tu-154 crashApril 10, 2010Polish president Lech Kaczyński was among those killed the crash.
Airblue Flight 202July 28, 2010Crashed into the Margalla Hills near Islamabad, Pakistan
RusAir Flight 9605June 20, 2011Crashed near Petrozavodsk Airport (PES, ULPB). Tu-134 RA-65691.
First Air Flight 6560August 20, 2011Was an internal Canadian charter flight from Yellowknife Airport, Northwest Territories, to Resolute Bay Airport, Nunavut. It crashed approximately 2 km (1.2 mi) east of the Resolute Bay, Airport runway, in poor weather attempting a go-around after a failed ILS landing. 12 of the 15 people on board were killed.
Royal Norwegian Air Force C-130JMarch 15, 2012Crashed into Kebnekaise, Sweden en route to Kiruna Airport, killing the 5 officers on board. C-130J-30 'Siv'.
Mount Salak Sukhoi Superjet 100 crashMay 9, 2012Aircraft crashed while on a demonstration flight, killing all 45 on board. The pilots had intentionally turned off the terrain warning system and were speaking to potential customers when the impact occurred.

See also[edit]


  1. ^
  2. ^ a b "Boeing: Commercial Airplanes - Jetliner Safety - Industry's Role in Aviation Safety". Archived from the original on June 29, 2011. Retrieved June 2013. 
  3. ^ [1][dead link]
  4. ^ Boeing Training Aid Addresses Leading Accident Cause, Feb. 20, 1997
  5. ^ Air Force Magazine, February 2004, Published by Air Force Association, 1501 Lee Highway, Arlington, VA 22209-1198, USA.
  6. ^ (Parmet, AJ and Ercoline, WR, Chapter 6, Spatial Orientation in Flight. In Fundamentals of Aerospace Medicine, 4th Edition, 2008, Davis, Johnson, Stepanek and Fogarty, Eds. Lippincott Williams & Wilkins)
  7. ^ Honeywell Aerospace EGPWS Website
  8. ^ [2]
  9. ^ a b David Learmount (January 13, 2009). "Forecasts 2009 - Safety and security are in the doldrums". Flight International. Retrieved 2009-11-04. 
  10. ^
  11. ^ Accident description for S2-ABJ at the Aviation Safety Network
  12. ^ "AROUND THE WORLD; 49 Die in Bangladesh As Plane Plunges". The New York Times. 6 August 1984. Retrieved 2 September 2014. 

External links[edit]