Controlled flight into terrain
Controlled Flight into or toward Terrain - German controlled flight into terrain or towards (usually short Controlled Flight into Terrain or CFIT ) - is a category of flight accidents in which a fully controllable aircraft isflownby the crew against the surface of the earth or against an obstacle . In general, the crew is not aware of the impending collision.
The International Civil Aviation Commission (ICAO) and the Commercial Aviation Safety Team define CFIT as the impact or near-collision of an aircraft in flight with a surface of land, water or an obstacle without any evidence that the aircraft has previously been lost control. A CFIT can take place under instrument flight conditions (IMC) as well as under visual flight weather conditions (VMC) and also includes cases in which the pilots are subject to optical deception or limited visibility, such as brownout or whiteout .
CFIT does not apply to situations in which the crew is aware of the dangerous situation but cannot avoid the collision. This is especially the case when technical or human error or adverse weather conditions lead to the loss of control of the aircraft. In this case one speaks of Loss of Control Inflight (LOC-I).
Also not covered by the term CFIT are aircraft accidents that occur in the following situations:
- Incidents when intended to fly at low altitude, such as agricultural flights , work flights near obstacles and SAR missions. These accidents are classified as Low Altitude Operations (LALT).
- Incidents during take-off and landing ( Collision With Obstacle (s) During Takeoff and Landing , CTOL)
- Suicides ( Security Related , SEC)
- Incidents with unmanned aircraft ( System / Component Failure or Malfunction (Non-Powerplant) , SCF-NP or Loss of Control-Inflight , LOC-I)
- Missing the runway ( Undershoot / Overshoot , USOS).
Between 1946 and 1955 there was an average of 3.5 cases each year in which an airworthy, controllable passenger aircraft was flown off-road. This accumulation of CFIT accidents led to the development and introduction of the ground proximity warning system GPWS in the 1970s . By 1980, despite the sharp increase in air traffic, the risk had been reduced to around two CFITs per year.
The further development of the Enhanced Ground Proximity Warning System (EGPWS), also known as the “Terrain awareness and warning system” (TAWS), enabled the number of accidents to be reduced even further. The current aircraft position is compared with an internal terrain database so that the crew can be visually informed and, if necessary, alerted much earlier than when using the radar altimeter .
Prevention of CFIT accidents
Several strategies are used to prevent such accidents.
In instrument flight and instrument landings, minimum flight altitudes apply, which must not be fallen below. On a VOR-DME approach, for example, cockpit instruments show the correct direction of the approach, as well as the distance to the airport. On an approach chart, the crew can read off at which distance and which altitude should be maintained.
A computer-aided warning is issued on the air traffic control side if the aircraft is flying too low. However, such monitoring only takes place in the vicinity of airports and only if air traffic control is appropriately equipped.
On the aircraft side, there are various techniques that are intended to prevent CFIT accidents.
- The radar altimeter warns if you are flying close to the ground without the flaps or landing gear extended. Far from an airport, however, it is still possible to collide with the terrain in a controlled "landing approach".
- The above technology is supplemented by the navigation system: A warning is issued if the flaps and landing gear are extended in low flight, but there is no airport nearby.
- The current state of the art (2010s) is EGPWS (Enhanced Ground Proximity Warning System) or TAWS (Terrain Awareness and Warning System): The warning system accesses a digital terrain database. Based on the satellite navigation , it is calculated whether the aircraft is on a collision course with the terrain. EGPWS includes the terrain, the direction of flight and the airspeed, and prompts the pilots to climb if there is a threat of a collision with the terrain within a certain time frame.
Examples of CFIT incidents
- August 15, 1939: In the Stuka accident in Neuhammer , 13 Junkers Ju 87s fell into the ground. The formation should plunge through a cloud cover; Due to an unexpectedly low cloud base, the pilots could only see the ground at a height of around 100 meters and could no longer intercept the aircraft in time.
- July 28, 1945: A B-25 bomber collided with the Empire State Building in thick fog .
- 2 August 1947: The crash of the Star Dust aircraft collided type Avro 691 Lancastrian 3 with the air vehicle registration G-AGWH on the flight with the number CS59 from Buenos Aires to Santiago de Chile in the Argentine Andes with the volcano Tupungato . While crossing the Andes, the crew was probably caught in a jet stream blowing towards the aircraft at high speed, which slowed the aircraft down considerably in terms of ground speed . Due to the weather, the crew believed they were already beyond the Andes due to the elapsed flight time and began to descend too early. The plane was lost for over 50 years before a group of mountaineers discovered the first wreckage at the foot of the mountain on January 23, 2000, which the glacier there had released after decades.
- November 3, 1950: A Lockheed L-749 Constellation of Air India crashed on the Air India Flight 245 on Mont Blanc Vorgipfel Rochers de la Tournette. All 48 people on board died. The novel "The Mountain of Temptation" by Henri Troyat is based on this accident , which in turn became the basis for the US film " The Mountain of Temptation " from 1956 with Spencer Tracy and Robert Wagner . Even decades after the accident, finds are still being made in the area of the Glacier des Bossons glacier, which flows down the northern flank of Mont Blanc, from this accident and that of Air India flight 101 on January 24, 1966.
- September 10, 1952: After a combat mission during the Korean War , a formation of seven Grumman F9F-4 "Panthers" could not land on the Pohang military airfield due to bad weather and avoided the Daegu base . 43 km southeast of the alternate airfield, the entire group flew into a mountain, killing all 7 pilots.
- June 26, 1969: The Belgian sub-lieutenant Roger Louis Joseph Marquillier flew too low with his RF-84F-25-RE Thunderflash as part of the Sky Blue exercise and collided with the terrain near Laufenselden im Taunus in poor visibility . Today, a memorial stone in the forest commemorates the accident, and parts of the aircraft can still be found here.
- May 12, 2010: After the landing approach was canceled due to a lack of ground visibility, an Airbus A330-202 crashed on Afriqiyah Airways flight 771 . The crew had misjudged the attitude after the go - around.
Incorrect perception of the position
- January 24, 1966: With Air India Flight 101 crashed into a Boeing 707 -437 in the final approach to Geneva about 60 meters below the summit with about 500 km / h of Mont Blanc and crashed, with all 117 people on board killed came and could not be recovered. At the time of the accident, it was the number of fatalities after the second-most serious aircraft accident on French soil. Even decades after the accident, finds are still being made in the area of the Glacier des Bossons glacier, which flows down on the northern flank of Mont Blanc, from this accident and that of Air India flight 245 on November 3, 1950.
- Air accident involving a Transall C-160 in Crete in 1975
- January 2, 1988: On the approach to Izmir, a Boeing 737 on Condor flight 3782 crashed into a mountain. The cause was a navigation error due to the reception of a side lobe from the instrument landing system . All 16 inmates died.
Incorrect perception of flight altitude
- On February 29, 1964, a Bristol Britannia (G-AOVO) flew on British Eagle flight 802 in poor visibility conditions on the approach to Innsbruck against Mount Glungezer . The pilots had fallen below the applicable, safe minimum flight altitude without having visual contact with the airport.
- May 20, 1965: A Boeing 720-040B on Pakistan International Airlines Flight 705 (AP-AMH) sank too early on its approach to Cairo International Airport and flew 20 kilometers south of the runway into the desert. Six passengers survived the accident, but a total of 121 people on board were killed, including 108 passengers and the entire crew of 13 people.
- December 29, 1972: On Eastern Air Lines flight 401, a Lockheed L-1011 TriStar collided with the bottom of the Everglades on its way from New York to Miami.
- September 28, 2005: The rescue helicopter Christoph 51 of the type BK 117 collided with the western slope of the Boßler while on an ambulance to Munich . All four inmates were killed.
Incorrect perception of the terrain
- May 9, 2012: In the accident of a Sukhoi Superjet 100 manufactured by the manufacturer, a Superjet (RA-97004) flew on a demonstration flight over Indonesia against Mount Gunung Salak . All 45 inmates were killed. The pilots had switched off the correctly functioning EGPWS , which would have warned of the mountains. They wrongly assumed that there was no such high mountain in the vicinity (see also the Sukhoi Superjet 100 accident in Indonesia in 2012 ) .
Deliberately falling below the minimum descent altitude
- On October 19, 1988, the pilots of a Boeing 737-200 from Indian Airlines (VT-EAH) fell below the minimum descent altitude on the approach to Ahmedabad airport in poor visibility . The machine brushed against a high-voltage pylon, crashed into a rice field, and went up in flames. Of the 135 people on board, 133 died (see also Indian Airlines flight 113 ) .
- November 24, 2001: On the approach to Zurich, an Avro RJ100 aircraft of the Swiss Crossair crashed after touching trees near Bassersdorf , Canton Zurich . The cause was deliberately falling below the minimum descent altitude. Of the 33 occupants, 24 died (see also Crossair flight 3597 ) .
Incorrect operation of the flight management system
- On February 14, 1990, 94 people died after the captain of an Airbus A320-200 operated by Indian Airlines (VT-EPN) , when approaching HAL Bangalore International Airport , set a target height (too low) instead of a rate of descent. The pilots noticed their mistake too late to be able to avert the impact on a golf course shortly before the destination airport (see also Indian Airlines flight 605 ) .
- On 20 December 1995 159 people were killed when a Boeing 757 of American Airlines (N651AA) near Cali , Colombia with a mountain of Andean collided. Several waypoints had previously been entered incorrectly in the flight management system, so that the aircraft was on a flight path that was not planned and led to significantly higher terrain than intended (see also American Airlines flight 965 ) .
- Controlled Flight Into Terrain. Flight Safety Foundation (English)
- Les accidents de type CFIT. Securite Aerienne (French)
- CAST / ICAO Common Taxonomy Team: Aviation Occurence Categories. Version 4.7, December 2017, p. 9 (PDF, English, accessed on February 14, 2019).
- Controlled Flight into Terrain. Flight Safety Foundation, accessed February 14, 2019.
- Nicholas Sabatini: Downward Pressure on the Accident Rate ( Memento of April 16, 2014 in the Internet Archive ). International Society of Air Safety Investigators, Federal Aviation Administration (Speech May 12, 2006).
- Accident report L-749 Constellation VT-CQP, November 3, 1950. Aviation Safety Network (English, accessed on August 4, 2014).
- Accident report B-720 AP-AMH, May 20, 1965. Aviation Safety Network (English, accessed on August 17, 2017).
- Accident report B-737-200 VT-EAH , Aviation Safety Network (English), accessed on February 22, 2019.
- accident report B 757-223 N651AA, 20 December 1995. Aviation Safety Network (English, accessed on February 8, 2016).