The flight was intended to carry humanitarian aid from Karachi (Pakistan), and was on its way to Khartoum (Sudan). After successfully getting airborne from Jinnah International Airport (JIAP), Karachi, the aircraft Engine # 4 and adjacent right wing area caught fire. The flight could not be sustained and it crashed about 2 NM from the JIAP Karachi, fatally injuring all souls on board. The cause of the accident was uncontained failure of 2nd stage disk of Engine # 4 Low Pressure(LP) compressor during climb after takeoff. The debris from engine failure damaged the right wing and flaps in the vicinity of Engine # 4. Consequent to the damage, the fuel in the right wing caught fire and resulted in loss of lateral control. The most probable cause of the engine failure was the fatigue fracture of LP compressor second stage disk. The fatigue cracks developed due to fretting in the hole, designed for holding the bushing for LP compressor blade pin as the mishap engine was being used beyond its manufacturer’s assigned life at bearing of 070°.
