Controlled flight into terrain

Wreckage from Air New Zealand Flight 901, a CFIT accident that occurred in 1979 in Antarctica

A controlled flight into terrain (CFIT, usually pronounced "see-fit") is an accident in which an airworthy aircraft, under pilot control, is unintentionally flown into the ground, a mountain, a body of water or an obstacle.^[1] In a typical CFIT scenario, the crew is unaware of the impending disaster until too late. The term was coined by engineers at Boeing in the late 1970s.^[2]

Accidents where the aircraft is out of control at the time of impact, because of mechanical failure or pilot error, are not considered CFIT (they are known as uncontrolled flight into terrain), nor are accidents resulting from the deliberate action of the person at the controls, such as acts of terrorism or suicide by pilot.

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.^[3] CFIT was identified as a cause of 25% of USAF Class A Mishaps between 1993 and 2002.^[4]

Causes

Reconstruction of the final moments of Korean Air Flight 801, which crashed into a hill in Guam in 1997

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.^[1]

The most common type of pilot error in CFIT accidents is the failure of pilots 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.^[5]

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.

Solutions

Prior to the installation of the first electronic warning systems, the only defenses against CFIT were pilot simulator training, traditional procedures, crew resource management (CRM) and radar surveillance by air traffic services. While those factors undoubtedly reduced the total number 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.^[6]

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.^[7]

Statistics show that aircraft fitted with a second-generation EGPWS have not suffered a CFIT accident^[8] 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 disaster). As of 2007, 5% of the world's commercial airlines still lack a TAWS, leading to a prediction of two CFIT accidents in 2009.^[8] In the case of Mount Salak Sukhoi Superjet 100 crash, the TAWS was working but the pilot intentionally turned it off.^[9]

Notable accidents

Many notable accidents have been ascribed to CFIT.

Flight	Date	Comments
TWA Flight 3	January 16, 1942	Fifteen 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 Dust	August 2, 1947	Due 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 disaster	May 4, 1949	Collision with the hill of Superga, near Turin.
Pan Am Flight 151	June 21, 1951	Collision with hill, Liberia, Africa
United Airlines Flight 610	June 30, 1951	Crashed into Crystal Mountain, CO, after failing to make a required left turn, to remain on the flight planned course to Denver.
Air France Flight 178	September 1, 1953	Crashed into the Pelat Massif in the French Alps
British Commonwealth Pacific Airlines Flight 304	October 29, 1953	Premature descent while intercepting ILS for SFO airport
US Navy SNB-4 67260	January 9, 1955	Crashed into Cajon Mountain, near San Bernardion, CA, while in instrument flight conditions. Attempted instrument approach into Norton AFB while NDB at Norton was reported to be unusable. Crew of two and one passenger killed.
TWA Flight 260	February 19, 1955	Crashed into Sandia Mountains, near Albuquerque, NM, while in instrument flight conditions. Suspected failure of a critical navigation instrument.
United Airlines Flight 409	October 6, 1955	Unexplained deviation from flight plan course; hit Medicine Bow Peak, CO
Trans-Canada Air Lines Flight 810	December 9, 1956	Crashed into a mountain after crew deviated from a known flight path; a fire alarm in one engine and icing of the wings were contributing causes.
1958 Bristol Britannia 312 crash	December 24, 1958	Poor weather and a poorly-designed altimeter led to the crew overestimating their altitude by 10,000 feet.
American Airlines Flight 320	February 3, 1959	Crashed in New York City's East River on a night approach, due largely to a combination of poor cockpit management, improper use of the autopilot, and lack of situational awareness.
1959 Air Charter Turkey crash	April 23, 1959	Crew failed to notice that strong winds had made the flight drift into mountainous terrain.
Piedmont Airlines Flight 349	October 30, 1959	Navigational error led to the flight impacting a hill short of the airport.
TAA Fokker Friendship disaster	June 10, 1960	No cause was ever established; theories include altimeter malfunction or interference by a child visiting the cockpit.
Alitalia Flight 771	July 7, 1962	Navigational error and lack of situational awareness led pilot to descend prematurely.
Aero Flight 217	November 8, 1963	DC-3. Crashed into a knoll on landing approach at Mariehamn, Finland. The root cause was a malfunctioning altimeter.
Linjeflyg Flight 277	November 20, 1964	Crash killed 31 of 43 people on board, making it the deadliest aviation accident in Sweden.
United Airlines Flight 389	August 16, 1965	No official cause determined, but a leading theory was misinterpretation of a problematic 3-pointer altimeter.
American Airlines Flight 383	November 8, 1965	Poor weather and misreading of a drum-type altimeter may have led to an improperly-early descent.
TABSO Flight 101	November 24, 1966	Crashed Bratislava, Slovakia, killing all 82 on board
Iberia Airlines Flight 062	November 4, 1967	No official cause determined, but it was noted that the plane had the 3-pointer style of altimeter that had been suspected of contributing to a number of other accidents.
TWA Flight 128	November 20, 1967	Crashed 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 228	April 20, 1968	Failure by crew to maintain a safe airspeed and altitude and a positive climb by not observing flight instruments during take-off.
Scandinavian Airlines System Flight 933	January 13, 1969	Failure by crew to monitor rate of descent, resulting in a water landing near LAX
Prinair Flight 277	March 5, 1969	Crashed in mountainous terrain near Fajardo, Puerto Rico, killing all 19 occupants. The air traffic controller at Isla Verde International Airport in San Juan incorrectly thought the flight was near San Juan and instructed it to land.
Southern Airways Flight 932	November 14, 1970	Crashed near Ceredo, West Virginia, killing all 75 on board. The flight was chartered by Marshall University and the passengers consisted of players, coaches, and boosters of the football team returning from a game against East Carolina.
Alaska Airlines Flight 1866	September 4, 1971	Flew into the side of a canyon on approach to Juneau, Alaska. 111 fatalities (104 passengers, 7 crew)
Uruguayan Air Force Flight 571	October 13, 1972	Known 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 239	December 23, 1972	Faulty ILS signals and a distracted crew led to an impact miles from the runway.
Eastern Air Lines Flight 401	December 29, 1972	The 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 723	July 31, 1973	Crew misprogrammed flight director and failed to maintain control of glidepath during final approach.
Texas International Airlines Flight 655	September 27, 1973	Continued VFR flight into instrument meteorological conditions; poor navigation resulting in loss of situational awareness; captain ordered descent below minimum safe altitudes. Aircraft impacted Black Fork Mountain, Arkansas.
TWA Flight 514	December 1, 1974	Bad weather and poor communications between the crew and ATC led to an improper descent.
Turkish Airlines Flight 452	September 19, 1976	Crashed into a hill 60 miles off the destination airport killing all 154 people on board.
Air New Zealand Flight 901	November 28, 1979	Crashed 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 1008	April 25, 1980	Crashed into high terrain in Tenerife after turning the wrong way in a holding pattern. All 146 people aboard were killed.
Inex-Adria Aviopromet Flight 1308	December 1, 1981	Struck Corsica's Mt. San Pietro and crashed shortly before it was scheduled to land. All 180 people on board were killed.
VASP Flight 168	June 8, 1982	Highest death toll of aviation accidents in Brazil for 24 years. Sensory illusion during a night approach led to the captain descending below minimum safe altitude, despite warnings from the plane's automated systems and the first officer.
Avianca Flight 011	November 27, 1983	Pilot/navigational error led to premature descent into hilly terrain.
1984 Biman Bangladesh Airlines Fokker F27 crash	August 5, 1984	Worst air disaster in history of Bangladeshi aviation.[10][11]
Eastern Air Lines Flight 980	January 1, 1985	Struck 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 crash	October 19, 1986	President Machel of Mozambique and 33 others die when their off-course plane descends and flies into the Lebombo Mountains.
Avianca Flight 410	March 17, 1988	Failure to maintain a sterile cockpit coupled with pressure from a delayed departure led to the aircraft impacting a mountain minutes after lift-off.
Air France Flight 296	June 26, 1988	Crashed 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 113	October 19, 1988	The 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 1851	February 8, 1989	Crew failed to request clarification of faulty information given to them by a trainee ATC.
Flying Tiger Line Flight 66	February 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 764	June 7, 1989	Captain knowingly initiated the wrong type of approach that relied on faulty ground equipment.
Indian Airlines Flight 605	February 14, 1990	Crashed short of the runway during final approach to Bangalore, killing 92 on board.
Death of Stevie Ray Vaughan, East Troy, Wisconsin	August 27, 1990	Bell 206B Jet Ranger helicopter flown into the side of a hill in heavy fog.
Alitalia Flight 404, Zurich	November 14, 1990	DC-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.
Royal Air Force Tornado ZA392	17/01/1991	Tornado GR1 crashed into the ground 16 km (9.9 mi) after delivering a JP233 munition. Both crewmembers were killed.
Air Inter Flight 148	January 20, 1992	Crashed into Mt. Ste. Odile in the Vosges Mountains whilst on approach into Strasbourg Entzheim Airport.
Thai Airways International Flight 311	July 31, 1992	Crashed on approach to Kathmandu. All 113 people on board were killed, 59 days before the PIA Flight 268 accident at Kathmandu.
PIA Flight 268	September 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 501	May 19, 1993	Crashed near Mt. Panamo Frontino, killing all 132 people on board the Boeing 727-100
Asiana Airlines Flight 733	July 26, 1993	While 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 703	June 5, 1995	A landing gear malfunction led to loss of situational awareness and descent below minimum safe altitude. Questions were raised about whether improper painting may have prevented the ground proximity warning system from functioning correctly.
American Airlines Flight 1572	November 12, 1995	Failure to update an altimeter setting and control the plane's descent led to impact with trees short of the runway.
American Airlines Flight 965	December 20, 1995	Crashed 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 crash	April 3, 1996	A modified Boeing 737 crashed into a mountain in Croatia.
Vnukovo Flight 2801	August 29, 1996	All 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; this circumstance thus leads to higher risks at landing.
1996 New Hampshire Learjet crash	December 24, 1996	Found November 13, 1999
Korean Air Flight 801	August 6, 1997	A 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 ATCO had modified its MSAW system to eliminate false alarms.
Garuda Indonesia Flight 152	September 26, 1997	An Airbus A300, registered PK-GAI, crashed in Pancur Batu, Pematang Siantar, North Sumatra, becoming the worst air disaster in Indonesian aviation history.
Cebu Pacific Flight 387	February 2, 1998	A DC-9-32, registered RP-C1507, crashed on the slopes of Mount Sumagaya in Claveria, Misamis Oriental, killing all 104 people on board.
Kenya Airways Flight 431	January 30, 2000	Impacted 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 541	April 19, 2000	Crashed 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 3597	November 24, 2001	Flight from Berlin to Zurich that crashed during its landing approach, killing 24 people.
Air China Flight 129	April 15, 2002	Crew failed to execute a timely missed approach.
Kam Air Flight 904	February 3, 2005	No official cause has been determined, although the plane flew into the area's worst snowstorm in five years.
2005 Loganair Islander accident	March 15, 2005	Pilot continued descent past minimum altitude for procedure turn. Factors included fatigue, workload, lack of recent flying time, and possible disorientation, distraction, or subtle incapacitation.
2006 Slovak Air Force Antonov An-24 crash	January 19, 2006	Aircraft strayed from the planned course and descended below the MDA prior to impact.
Armavia Flight 967	May 3, 2006	Bad weather, spatial disorientation, and loss of situational awareness coupled with failure to follow communications procedures between ATC, the ground meteorologist, and the crew led to improper flight inputs and impact with the Black Sea.
Atlasjet Flight 4203	November 30, 2007	While no official cause could be determined, investigators have theorized that the pilot suffered spatial disorientation before impact with a mountain.
Santa Bárbara Airlines Flight 518	February 21, 2008	The pilots took off without conducting the mandatory pre-flight procedures and used an unauthorized departure route, which led to impact with a mountainside within minutes of departure.
2010 Polish Air Force Tu-154 crash	April 10, 2010	Polish president Lech Kaczyński was among those killed in the crash.
Airblue Flight 202	July 28, 2010	Crashed into the Margalla Hills near Islamabad, Pakistan
RusAir Flight 9605	June 20, 2011	Crashed near Petrozavodsk Airport (PES, ULPB). Tu-134 RA-65691.
First Air Flight 6560	August 20, 2011	Was 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-130J	March 15, 2012	Crashed into Kebnekaise, Sweden en route to Kiruna Airport, killing the 5 officers on board. C-130J-30 'Siv'.
Mount Salak Sukhoi Superjet 100 crash	May 9, 2012	Aircraft 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

• Acronyms and abbreviations in avionics
• Air safety
• Minimum Safe Altitude Warning (MSAW)
• Traffic Collision Avoidance System (TCAS)

References

External links

• CFIT articles in SKYbrary: The single point of reference in the network of aviation safety knowledge
• Aviation occurrence categories: Definitions and usage notes (CAST/ICAO)