Accident Overview
On an evening flight from Frunze Airport, Kirghizistan, to Leninabad, Tajikistan, a Yakovlev Yak-40 aircraft crashed into a mountain, resulting in the destruction of the aircraft and the deaths of all 21 people on board. The flight carried 18 passengers and 3 crew members.
Flight History
The aircraft departed Frunze at 2024LT under good weather conditions. The crew climbed to the assigned altitude of 5,700 meters. During the en route phase, the crew failed to notice that the aircraft had deviated westward from the prescribed flight path. They incorrectly reported to ATC that they had passed over the cities of Namangan and Kokand. At 2121LT, the Leninabad-based ATC cleared the crew to descend to 3,300 meters and then to 2,100 meters, unaware of the aircraft's exact position. In darkness, while flying at 500 km/h, the aircraft struck the slope of Mount Airy Tash, which has an elevation of 2,300 meters. The mountain is located roughly 90 kilometers northeast of Leninabad. The impact caused the aircraft to disintegrate.
Investigation Findings
The official investigation concluded that the accident was a controlled flight into terrain. The crew's poor flight planning, incorrect in-flight decisions, and navigation errors led to the aircraft being off course. Several contributing factors were identified:
- ATC assistance was lacking, as controllers failed to verify the aircraft's position before clearing it to descend to 2,100 meters over mountainous terrain.
- ATC did not properly utilize available navigational aids, and overall ATC coverage was inadequate.
- Both pilots had limited experience on the Yak-40, having recently qualified on the type.
- They lacked experience in instrument flight rules (IFR) operations and night flying.
- The captain had a prior disciplinary record for serious flight rule violations but had recently been permitted to conduct passenger-carrying night flights on the Yak-40.
This was the first accident involving a Yak-40.
Probable Cause
The official probable cause states: "Poor flight planning, erroneous in-flight decisions and navigation errors on part of the flying crew caused the aircraft to be off-course at the time of the accident, resulting in a controlled flight into terrain." The following contributing factors were reported: - Lack of ATC assistance who failed to properly check the exact position of the aircraft before clearing the crew to descent to 2,100 meters over mountains terrain, - ATC failed to use properly the different navaids, poor ATC coverage, - Both pilots were relatively inexperienced on this type of aircraft as they were recently qualified on Yak-40 type, - Lack of experience in IFR flight and by night, - Despite the fact that the captain had already been disciplined for serious violations of flight rules, he had recently been allowed to fly with passengers on night flights on this type of aircraft.