Turkish Airlines Flight 634
Istanbul Atatürk Airport, Istanbul , Turkey | |
Destination | Diyarbakır Airport, Diyarbakır, Turkey |
---|---|
Occupants | 80 |
Passengers | 75 |
Crew | 5 |
Fatalities | 75 |
Injuries | 3 |
Survivors | 5 |
Turkish Airlines Flight 634 was a scheduled domestic passenger flight from
Background
Aircraft
The aircraft involved in the accident was a 1993-built
Crew and passengers
The
Accident
Flight 634 departed
When the flight was 8 nautical miles (15 km) from runway 34 and at an altitude of 5,000 feet (1,500 m), air traffic control instructed the crew to continue the approach and report as soon as they had established visual contact with the runway. The crew acknowledged the call and prepared the aircraft for landing, deploying the landing gear and extending the flaps. Continuing to descend, the aircraft reached its minimum descent altitude (MDA) of 2,800 feet (850 m) – the lowest altitude to which descent is authorized on final approach or during circle-to-land maneuvering in execution of a standard instrument approach procedure where no electronic glideslope is provided (the airport was not equipped with an instrument landing system) – but both pilots said that they still had no visual reference to the runway or its approach lighting system because of the thick fog. One pilot discerned some lights in the distance but was not sure what exactly they belonged to.[2][8]
Nonetheless, violating standard procedures, the captain decided to continue the approach to as close as 1 mile (1.6 km) to the runway and descended further to 500 feet (150 m) and beyond, well below the MDA. At 1 mile (1.6 km) off the threshold of the runway and at an altitude of 200 feet (60 m) (which in this case constituted the decision height), the ground proximity warning system (GPWS) started to trigger aural alarms. Eight seconds later, the crew decided to abort the landing and initiated a go-around, but before being able to execute the command, the airplane struck the ground with the undersurface of the fuselage and the landing gear at 20:19 EET (18:19 UTC), 900 metres (3,000 ft) off the threshold of runway 34 and 30 metres (100 ft) off the approach lights at a speed of around 131 knots (243 km/h; 151 mph).[2][9]
The aircraft slid on the ground for about 200 metres (660 ft) while starting to disintegrate. Eventually, it hit a slope, broke up into three major pieces, exploded and caught fire; most of the bodies and parts of the wreckage were burnt. The debris was spread out in an area of about 800 square metres (8,600 sq ft).[2][10]
The impact instantly killed both pilots, the three flight attendants and 69 of the 75 passengers. Six passengers survived, one of whom however later succumbed to his injuries in hospital.[2]
Immediate response
Since the crash site was within the boundaries of the airport, search and rescue teams of the
Investigation
This section needs additional citations for verification. (January 2019) |
The investigation into the accident was carried out by Turkey's
According to records, Captain Yunak and First Officer Ulusu were found to have been properly trained, qualified and experienced. They had sufficient rest before reporting for duty on the day of the accident. Drug and alcohol tests returned negative results.
Investigators also turned their attention to the aircraft, but were not able to detect any abnormalities. All maintenance checks were completed properly. Close examination of the engines revealed that they were operating normally at the time of the accident. The aircraft was properly configured for landing – the flaps and the landing gear were extended properly and the altimeter was set correctly – and the ground proximity warning system (GPWS) also produced alarms which could be easily heard on the CVR recordings.
Search and rescue teams who immediately rushed to the site to respond to the crash reported thick fog at the crash site and complained about the lack of visibility which according to their account was as low as 1 metre (3 ft) at times. This clearly contradicts the weather report the air traffic controller at Diyarbakır Airport had relayed to the crew minutes before the crash. According to them, the fire could not even be seen until arriving on the scene.
Analysis of the FDR and the CVR revealed that at the moment the aircraft struck the ground it was at a heading of 339° (north-northwest, in line with the runway centerline) and 900 metres (3,000 ft) short of the threshold of runway 34 at a positive pitch angle of five degrees (which corresponds to a slight nose-up position). The autopilot was found to have been activated up until a short time before the accident.
Final report
The investigation was completed around two years later in April 2005 and concluded that:[2]
- The crew failed to properly respond to the warnings produced by the GPWS and instead insisted on landing despite insufficient visual reference to the runway and its environment
- Thick fog contributed to the cause of the accident.
The Turkish Airline Pilots Association stated that an instrument landing system might have prevented the accident.[12]
See also
- Crossair Flight 3597 – An Avro RJ100 which crashed in similar circumstances.
- 2010 Polish Air Force Tu-154 crash– A crash of the Polish presidential airplane while the pilots were trying to establish a visual contact in an unfamiliar airport in thick fog.
- Air China Flight 129
- American Airlines Flight 965
- Trigana Air Flight 267
- Santa Barbara Airlines Flight 518
- Alitalia Flight 404
- PIA Flight 268
- Thai Airways International Flight 311
References
- ^ "Hava Aracı Kazası Nihai Raporu" [Aircraft Accident Final Report] (PDF) (in Turkish). Directorate General of Civil Aviation. 1 April 2005. Archived from the original (PDF) on 27 March 2014. Retrieved 25 August 2016.
- ^ a b c d e f g "Kaza Kırım" [Accident Crimea] (in Turkish). Directorate General of Civil Aviation. 25 October 2004. Archived from the original on 14 June 2008. Retrieved 25 August 2016.
- ^ "Accident Avro RJ100 TC-THG,". aviation-safety.net. Retrieved 26 May 2024.
- ^ "Scot killed in Turkey air crash". BBC News. BBC. 9 January 2003. Retrieved 28 December 2008.
- ^ "Diyarbakır'daki Uçak Kazasında Ölen 75 Kişiden 61'i Teşhis edildi" [61 of 75 people killed in plane crash in Diyarbakır were diagnosed] (in Turkish). Haber Vitrini. Archived from the original on 20 July 2011. Retrieved 29 December 2008.
- ^ "Tutanak" [Minutes] (PDF) (in Turkish). Grand National Assembly of Turkey. 9 September 2005. Retrieved 25 August 2016.
- ^ "TBMM Başkanlığına" [To the Presidency of the Parliament] (PDF) (in Turkish). Grand National Assembly of Turkey. 21 July 2005. Retrieved 25 August 2016.
- ^ "MİLLİYET İNTERNET – GÜNCEL HABERLER" [MİLLİYET INTERNET - CURRENT NEWS]. www.milliyet.com.tr (in Turkish). Retrieved 23 August 2016.
- ^ "Kaza Değil İntihar" [Suicide, Not Accident] (in Turkish). Retrieved 23 August 2016.
- ^ a b "Diyarbakır'da THY uçağı düştü" [THY plane crashes in Diyarbakır]. NTV MSNBC (in Turkish). 9 January 2003. Retrieved 28 December 2008.
- ^ "Turkish Airlines plane crashes, 75 dead, 5 survivors". CNN. 8 January 2003. Retrieved 29 December 2008.
- ^ "ILS olsaydı kaza riski en aza inerdi" [The risk of accidents would be minimized if ILS was] (in Turkish). NTV MSNBC. 9 January 2003. Retrieved 28 December 2008.