Investigation Summary
The accident took place during a large-scale operation in the Eranga Valley. Ground commandos from the Mountain Commando Group (GCP) had engaged Islamic State insurgents and requested air support as night fell. The mission involved a total of five helicopters: two Gazelle attack helicopters and one Cougar transport helicopter (callsign Celtic) arriving first from Ménaka, followed by two Tiger attack helicopters (including callsign Gazelle 1) from Gao. Two Mirage 2000 jets were also in the area. At the time of the collision, moon illumination was less than 1%, creating a 'complete darkness' environment. The Tiger (Gazelle 1) and the Cougar (Celtic) were maneuvering at approximately 1,000 meters (3,300 feet) when they collided. The investigation by the BEA-É found that the crews had erroneous situational awareness of each other's positions. The lack of automated collision avoidance systems meant the pilots relied entirely on 'see and avoid' procedures, which were rendered ineffective by the darkness and dust from the ground combat.
Final Conclusions
The French military air accident investigation bureau (BEA-É) released its final report (T-2019-15-A) on 30 January 2021. The report ruled out mechanical failure and enemy fire. The primary cause was attributed to organizational and human factors, specifically the failure of the crews to detect converging trajectories in a degraded visual environment while focused on high-intensity ground combat. The report highlighted that the helicopters were not equipped with collision avoidance systems, which could have alerted the pilots to the impending disaster.
Video Analysis
No video analysis linked for this case file yet.
Systems & Failure Modes
Collision Avoidance System
The investigation noted that the absence of these systems forced pilots to rely on visual 'see and avoid' techniques, which failed in the dark, dusty environment.
Night Vision / Visual Environment
Crews operated in a 'degraded visual environment' due to near-zero moon illumination and dust kicked up by ground operations.
TACAN (Tactical Air Navigation)
A system providing distance between aircraft; the investigation found it was neglected by the Cougar crew who were focused on the tactical mission.
Optronics / Thermal Camera
The Cougar crew took on an image intelligence mission using this system despite lacking specific Crew Resource Management (CRM) training for its use during tactical maneuvers, contributing to their mental load and distraction.
Interesting Facts
- 01The accident was the deadliest incident for the French military since the 1983 Beirut barracks bombings.
- 02Moon illumination at the time of the crash was less than 1%.
- 03Neither helicopter was equipped with an automated collision avoidance system.
- 04The collision occurred at an altitude of approximately 1,000 meters (3,300 feet).
- 05All 13 service members on board both aircraft were killed instantly.
Safety Actions & Advisories
Equipment Review
Source ↗The BEA-É report emphasized the need for collision avoidance systems on military helicopters to prevent similar accidents in high-intensity, low-visibility combat zones.
Communication Procedures
Source ↗The BEA-É recommended that the French Army define clear rules and procedures for aircraft collision avoidance and ensure these are reviewed during pre-mission briefings.
CRM Training
Source ↗The investigation highlighted the need for Crew Resource Management (CRM) training for crews operating specialized equipment like thermal cameras during tactical flight phases.
Known Controversies & Unanswered Questions
Islamic State Claim of Responsibility
Reference ↗Three days after the crash, the Islamic State in West Africa claimed their fire caused the helicopters to collide. This was officially denied by the French Chief of Staff, who stated there was no jihadist fire directed at the aircraft.