 Over half of the 840 aircraft built between 1966 and 1984 were lost to crashes.When in afterburner, the engine operates very close to its surge line and the ingestion of even a small bird can lead to an engine surge/seizure and flame out.On 11 December 2013, India's second-generation supersonic jet fighter, MiG-21FL was decommissioned after being in service for 50 years.