History of the Flight
On 27 November 2010, an Ilyushin Il-76TD aircraft, registration 4L-GNI, operated by Sunway Air Carrier (Georgia), was conducting a flight from Jinnah International Airport (JIAP), Karachi, Pakistan, to Khartoum, Sudan, carrying humanitarian aid. The aircraft had arrived earlier that day from Fujairah, UAE, after flying from Kandahar. The crew, consisting of seven Ukrainian and one Russian national, rested for at least eight hours before the return flight. The aircraft was refuelled with 74 tons of fuel and loaded with 30.5 tons of cargo (tents). The total takeoff mass was 197 tons with a center of gravity at 30% MAC.
At 2048 UTC, the aircraft took off from runway 25L. According to radar data, it climbed to 600 feet, then began descending and disappeared from radar. The air traffic controller received no emergency call from the crew.
Injuries and Fatalities
The accident resulted in fatal injuries to all eight occupants on board: six crew members and two engineering support specialists. Additionally, three ground workers in a residential area were killed. The aircraft crashed in an under-construction residential area, damaging several houses.
Damage to Aircraft and Other Property
The aircraft was destroyed by impact and fire. Several under-construction houses on the ground were severely damaged.
Personnel Information
The flight crew included an Aircraft Commander (Captain), a First Officer, a Navigator, a Flight Engineer, a Flight Radio Operator, and a Flight Operator. The Captain held a valid license and medical certificate, with over 7,272 total flight hours, including 5,502 on the Il-76. The First Officer had 2,220 flight hours. All required pre-flight actions were performed.
Aircraft and Engine Information
The aircraft was an Il-76TD with four engines. The flight history of the mishap engine (Engine #4) is documented. The engine had been operated beyond its manufacturer's assigned life at a bearing of 070°.
Cause of the Accident
The investigation determined that the cause of the accident was an uncontained failure of the 2nd stage disk of the No. 4 engine low-pressure compressor during climb after takeoff. Debris from the failure damaged the right wing and flaps, leading to a fuel fire and loss of lateral control. The most probable cause of the engine failure was a fatigue fracture of the LP compressor second stage disk. Fatigue cracks developed due to fretting in the hole designed for holding the bushing for the LP compressor blade pin, as the engine was being used beyond its manufacturer's assigned life.