A piece of the remains of Air New Zealand Flight 901, which crashed in 1979. All 257 people on the plane were killed.
Controlled flight into terrain (CFIT) describes an accident in which an airworthyaircraft, under pilot control, is unintentionally flown into the ground, a mountain, water, or an obstacle.[1] The term was coined by engineers at Boeing in the late 1970s.[2] The pilots are generally unaware of the danger until it is too late.
According to Boeing, CFIT "is a leading cause of airplane accidents involving the loss of life. There have been more than 9,000 deaths due to this since the beginning of the commercial jet age."[1]
Causes
According to Boeing, "there are many reasons why a plane might crash into terrain, including bad weather, imprecise navigation, and pilot error. In fact, pilot error is the single biggest factor leading to a CFIT incident."[1] Pilots with any level of experience, even highly experienced professionals, may commit CFIT. Pilot fatigue, loss of situational awareness, or disorientation may play a role. The incidents often involve a collision with significantly raised terrain such as hills or mountains, and may occur in conditions of clouds or otherwise reduced visibility. CFIT often occurs during aircraft descent to landing, near an airport. CFIT may be associated with subtle equipment malfunctions. If the malfunction occurs in a piece of navigational equipment and it is not detected by the crew, it may mislead the crew into improperly guiding the aircraft despite other information received from all properly functioning equipment, or despite clear sky visibility that should have allowed the crew to easily notice ground proximity (compare tunnel vision).
Solutions
Traditionally adequate procedures and crew coordination and communication (CRM) as well as control or surveillance by air traffic services may reduce the likelihood of CFIT.
In order to prevent the occurrence of CFIT accidents, manufacturers and safety regulators developed terrain awareness and warning systems (TAWS). The first generation of these TAWS systems is known as a ground proximity warning system (GPWS), which uses a radar altimeter to assist in calculating terrain closure rates. This system has now been further improved with the addition of a GPS terrain database and is known as an enhanced ground proximity warning system (EGPWS). This and the older system have mandatory pilot procedures and actions following any caution or warning event.[3]
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. [4]
Statistics show that aircraft fitted with a second-generation EGPWS have not suffered a CFIT accident.[5] As of 2007, 5% of the world's commercial airlines still lack a TAWS, leading to a prediction of two CFIT accidents in 2009.[5]
Notable accidents
Many notable accidents have been ascribed to CFIT.
The crash of the Star Dust airliner on 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.
The Superga air disaster, May 4, 1949, in which almost the entire Torino A.C. football team was killed in a collision with the hill of Superga, near Turin.
Uruguayan Air Force Flight 571 — known less formally as the Andes flight disaster, October 13, 1972 to December 23, 1972, during which stranded snow-bound survivors resorted to cannibalism. File:Accidente 1972.jpgSurvivors amongst the wreckage of Uruguayan Air Force Flight 571 The incident became the subject of feature films and best-selling books.
The crash of Eastern Air Lines Flight 401 near Miami, Florida on 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.
The crash of Air New Zealand Flight 901 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 preprogrammed coordinates, 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.
Mt. San Pietro disaster — December 1, 1981. Inex-Adria Aviopromet Flight 1308, flying from Ljubljana, Slovenia, to Ajaccio, Corsica, crashed into mountains shortly before it was scheduled to land. All 180 people on board were killed.
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.
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.
The crash of Pakistan International Airlines Flight 268 on approach to Kathmandu on September 28, 1992. 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.
American Airlines Flight 965 — December 20, 1995. Crashed into a mountain near Cali, 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 152 of the 156 passengers were killed.
Garuda Indonesia Flight 152 - An Airbus A300, registered PK-GAI, crashed in Pancur Batu, Pematang Siantar, North Sumatera. Became the worst air disaster in Indonesian aviation history.
