Investigation Summary
The accident occurred during a night approach to Diyarbakir Airport's Runway 34, which was not equipped with an Instrument Landing System (ILS). The crew was performing a VOR/DME approach in visibility conditions that had deteriorated to 3,500 metres according to the weather report, though conditions at the threshold were described as dense fog. Investigation of the flight data and cockpit voice recorders revealed that the crew failed to initiate a go-around after reaching the Minimum Descent Altitude (MDA) of 2,800 feet without having the runway environment in sight. Instead, they continued the descent into the fog. The aircraft struck the ground on a slope 900 metres south of the runway, dragged for 200 metres, and was destroyed by impact forces and a post-crash fire. The investigation highlighted a lack of adherence to standard operating procedures regarding non-precision approaches and minimum altitudes.
Final Conclusions
The primary cause of the accident was the flight crew's decision to continue the approach and descent below the Minimum Descent Altitude (MDA) without establishing the required visual reference with the runway or its lights. Contributing factors included the presence of dense fog and the lack of an Instrument Landing System (ILS) at Diyarbakır Airport at the time of the accident.
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Crew Experience
Captain
Former Turkish Air Force pilot, joined Turkish Airlines in 1995.
First Officer
Joined Turkish Airlines in 1998.
Systems & Failure Modes
VOR/DME
A non-precision radio navigation system used for the approach; it provides bearing and distance but no vertical guidance.
Minimum Descent Altitude (MDA)
The altitude below which descent must not be made during a non-precision approach unless the required visual reference is established.
Interesting Facts
- 01The accident is the deadliest involving the British Aerospace 146 / Avro RJ aircraft family.
- 02The aircraft was named 'Konya'.
- 03Runway 34 at Diyarbakır was not equipped with an Instrument Landing System (ILS) at the time of the crash.
- 04The aircraft broke into three pieces upon impact and a post-crash fire broke out, which was a primary factor in the high fatality rate.
- 05Initially, six passengers survived the impact, but one child later died from injuries in the hospital.
- 06The wreckage was spread over an area of approximately 800 metres.
Safety Actions & Advisories
Approach Discipline Training
The accident reinforced the necessity for pilot training to emphasize strict adherence to Minimum Descent Altitudes (MDA) and the requirement for immediate go-arounds if visual references are not met.