Investigation Summary
Flight 2137 was a chartered flight transporting high-level aviation officials and engineers from Ukraine and Russia to Isfahan for the rollout ceremony of the HESA IrAn-140, a licensed version of the Antonov An-140. The aircraft performed a refueling stop in Trabzon, Turkey, before continuing toward central Iran. During the night-time descent into Isfahan International Airport, the crew encountered difficulties with their navigation. The Interstate Aviation Committee (IAC) investigation revealed that the pilots were using the aircraft's GPS in a manner that breached operational requirements and their specific ratings. Crucially, when the GPS failed to provide a realistic distance measuring equipment (DME) readout, the crew did not cross-check with other available navigation aids or abort the approach. This loss of situational awareness led the aircraft to impact high terrain near Ardestan, approximately 70 kilometers from the destination airport.
Final Conclusions
The primary cause was determined to be procedural navigation errors by the flight crew. Contributing factors included poor crew resource management (CRM), failure to apply standard approach procedures, and the incorrect use of the satellite navigation system (GPS) for the approach. The crew failed to seek an alternative approach or utilize traditional navigation equipment when the GPS data became unreliable.
Photographic Evidence (1)
Video Analysis
No video analysis linked for this case file yet.
Systems & Failure Modes
GPS (Global Positioning System)
The crew used the satellite navigation system incorrectly during the approach, in violation of operational requirements.
DME (Distance Measuring Equipment)
The crew failed to obtain a realistic distance readout from the GPS and did not verify their position using other equipment.
Interesting Facts
- 01The passengers included top aviation designers and officials from the Antonov Design Bureau and other Russian/Ukrainian aerospace firms.
- 02The crash occurred in mountainous terrain during a night-time approach.
- 03The aircraft involved, UR-14003, was extremely new, having recorded only 71 airframe hours and 27 landings.
- 04The flight was specifically organized for the inauguration of the Iranian-assembled An-140 (IrAn-140).
- 05While most official reports list 44 fatalities, some secondary sources have reported up to 46 people on board.
Safety Actions & Advisories
Crew Training and GPS Certification
The investigation emphasized the need for strict adherence to GPS operational ratings and the requirement for crews to cross-verify satellite data with traditional ground-based navigation aids.