Unknown
2021-MAR-04 · Near Tatvan, Bitlis Province, Turkey

Turkish Air Force — Flight Unknown

A Turkish Air Force Eurocopter AS532UL Cougar (serial 95-0445) crashed into a hillside near Tatvan, Bitlis Province, during a flight from Bingöl. The accident resulted in the deaths of 11 Turkish servicemen, including Lieutenant General Osman Erbaş. The investigation concluded that the helicopter encountered sudden, severe weather conditions including thick fog and snow, leading to spatial disorientation. While two personnel survived the impact, the aircraft was destroyed.

Aircraft
Eurocopter AS532UL Cougar
Registration
Phase
Cause
Souls on Board
13
Fatalities
11
Origin → Dest
Bingöl, Turkey → Tatvan, Bitlis, Turkey
Report

Investigation Summary

The helicopter departed Bingöl at 13:55 local time for a routine transit to Tatvan. Approximately 30 minutes into the flight, the crew encountered a sudden deterioration in weather, characterized by heavy clouds and snow that reduced visibility to near zero. The investigation by the Ministry of National Defence (MSB) found no technical malfunctions in the aircraft's engines or systems. Instead, the crash was attributed to 'spatial disorientation' caused by the abrupt loss of visual references in the mountainous terrain. The crash site was located near the village of Çekmece. This event marked the fourth major crash of an AS532 Cougar in Turkish service, prompting a national debate regarding the suitability of the aircraft for the region's high-altitude and volatile weather conditions.

Final Conclusions

The investigation by the Turkish Ministry of National Defence concluded that the crash was caused by spatial disorientation resulting from a sudden and severe deterioration in weather conditions. The crew encountered unexpected thick fog and snow while transiting mountainous terrain, which led to a loss of visual reference. Technical examinations of the wreckage and maintenance records confirmed that there were no mechanical failures or malfunctions in the engines or flight systems prior to impact.

Video Analysis

No video analysis linked for this case file yet.

Airframe & Maintenance

Engines
Turbomeca Makila

Systems & Failure Modes

i

Turbomeca Makila

The helicopter was powered by two Turbomeca Makila turboshaft engines.

i

Anti-missile Defense Systems

Following a 1997 shootdown of the same type, Turkish Cougars were historically scrutinized regarding their defensive suites, though no evidence of hostile fire was reported in this 2021 event.

Interesting Facts

  • 01The crash killed Lieutenant General Osman Erbaş, commander of the Turkish Army's 8th Corps.
  • 02Visibility at the time of the crash was reported as poor due to thick clouds and snow.
  • 03The aircraft was a Eurocopter AS532UL Cougar, a model that entered the Turkish inventory in 1996.
  • 04This was the fourth fatal crash of a Cougar helicopter in Turkish military service.
  • 05Two servicemen survived the accident and were treated for injuries.

Safety Actions & Advisories

Weather Monitoring and Flight Planning

Source ↗

The Turkish Ministry of National Defence emphasized the need for stricter adherence to weather minimums in mountainous regions following the determination that sudden fog caused spatial disorientation.

Fleet Review

Source ↗

Following the accident, the Turkish military conducted a comprehensive technical review of the AS532 Cougar fleet, though no grounding order was issued as no technical faults were found to have contributed to the crash.

Location

Near Tatvan, Bitlis Province, Turkey · 38.5022, 42.2814

Case File History

  1. Final reportUpdated final conclusions.
  2. Status changeUpdated report status, probable cause, investigation summary, event timeline and safety actions.

Related Cases

Case ID · taf-as532-2021Last updated · Filed

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