What happened
On 21 October 2009, a Boeing 707-330C cargo aircraft, registration ST-AKW, operated by Azza Air Transport, crashed during its departure from Sharjah International Airport. Shortly after takeoff, the aircraft lost control and impacted the ground approximately 1.6 kilometers from the end of runway 30. The impact was severe, causing the aircraft to be completely destroyed and subsequently consumed by fire. There were 6 fatal injuries, as all six crew members on board perished in the accident.
The investigation
The GCAA Air Accident Investigation Sector led the inquiry, coordinating with representatives from the Sudan Civil Aviation Authority, the NTSB, the FAA, Boeing, and Pratt & Whitney. Investigators examined the wreckage, flight recorders, and engine components to reconstruct the final moments of the flight. A significant portion of the technical analysis focused on the condition of the No. 4 engine's thrust reverser mechanism and the physical forces acting on the powerplant during the high-impact ground contact.
Findings
Technical analysis of the No. 4 engine revealed that while the thrust reverser was in the stowed position at the moment of impact, the extreme forces of the crash caused the mechanism to shift. The investigation established that the aircraft struck the ground in a nose-down and right-wing-down attitude. This impact drove the engine's translating sleeve past its stowed position into an over-stowed state, which subsequently caused the failure of various internal linkages, including the fracture of the upper and lower left drag links. The heavy loading during the crash also caused the engine's actuator rods to experience significant stress, though the lack of buckling in the lower rods suggested the thrust reverser had not been deployed prior to the impact.