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.
The term was coined by Boeing in the late 1970s.The pilots are generally unaware of the danger until it is too late. Accidents where an aircraft is damaged and uncontrollable (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.
While there are many reasons why a plane might crash into terrain, including bad weather and navigation equipment problems, it is claimed that pilot error is the single biggest factor leading to a CFIT incident.
Even highly experienced professionals may commit CFIT due to fatigue, loss of situational awareness, or disorientation. CFIT is considered to be caused by spatial disorientation, where the pilot(s) do not correctly perceive their position and orientation with respect to the Earth\’s surface.
The incidents often involve a collision with 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.
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. 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.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.
Statistics show that aircraft fitted with a second-generation EGPWS have not suffered a CFIT accident. if TAWS or EGPWS are properly handled (there are at least three CFIT accidents of planes with EGPWS/TAWS: Garuda Indonesia Flight 200, 2010 Polish Air Force Tu-154 crash, 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. In the case of Mount Salak Sukhoi Superjet 100 crash, the TAWS was working but the pilot intentionally turned it off.
Polish Air Force Tu-154M crash
occurred on 10 April 2010 when a Tupolev Tu-154M aircraft of the Polish Air Force crashed near the city of Smolensk, Russia, killing all 96 people on board. These included president Lech Kaczyński and other senior Polish government officials. The pilots attempted to land at Smolensk North Airport, a former military airbase, in thick fog that reduced visibility to about 500 metres (1,600 ft). The aircraft was too low as it approached the runway. Striking trees in the fog, it rolled upside down, impacted the ground, broke apart, and eventually came to rest 200 metres short of the runway in a wooded area. Altough the pilots were obtaining GPWS signals, they continued descent, being pushed to land by the head of Administration of the President.
RusAir Flight 9605. June 20, 2011 Crashed near Petrozavodsk Airport. Tu-134.
The aircraft crashed onto the A133 highway while on final approach to Petrozavodsk Airport, about 1,200 m (3,900 ft) short of the runway. The cause of the crash was not immediately clear. The crash happened about midnight local time in reportedly poor weather, including heavy fog. According to airport officials, the plane was flying off-course by about 200 metres (660 ft) and started its descent much earlier than appropriate. Petrozavodsk ground control said they recommended the pilots take a second approach due to the low visibility and bad weather conditions. The pilot, according to the official, replied that he would attempt the first approach and said he could land the plane.
The Mount Salak Sukhoi Superjet 100 (SSJ-100) crash
occurred on 9 May 2012 when an SSJ-100 aircraft crashed on a demonstration flight operating from Halim Perdanakusuma Airport, Jakarta, Indonesia. On 10 May, the wreckage of the Sukhoi Superjet was spotted on a cliff in Mount Salak, a volcano in the province of West Java. Due to the widespread debris field where the aircraft hit the mountain, rescuers concluded that the aircraft directly impacted the rocky side of the mountain and that there was no chance of survival. The final report, released 18 December 2012, indicated that the accident was caused by crew members ignoring terrain warnings that they had incorrectly attributed to a database problem. The crew had turned off the terrain warning system and were unaware that they were operating in close proximity to mountains. The crew, including the captain, were engaging in conversation with potential customers as the aircraft impacted the ground.