It wasn’t pilot error but a possible lapse during the aircraft upgrade process that led to the 1 February Mirage 2000 crash at the Hindustan Aeronautics Limited (HAL) airport in Bengaluru, the court of inquiry (CoI) has found. Two Indian Air Force (IAF) pilots testing the upgraded Mirage 2000, Squadron Leader Samir Abrol and Squadron Leader Siddhartha Negi, were killed in the crash. According to the CoI, the crash was caused by an “uninitiated control input” — or a software glitch — during the jet’s user acceptance trial. The CoI has also faulted the arrester barrier at the HAL airport runway, saying it failed to intercept the aircraft’s slide after it crashed. The arrester barrier is a net with two hydraulic jacks that is installed at the end of runways to ensure an aircraft does not overshoot it.