The weight shift alone did not cause the flight crew to lose control of the Boeing 747 freighter when a military vehicle being carried as cargo tore free of its tie-down straps in the aft cargo hold on initial climb from Bagram Air Base in Afghanistan.
The airplane actually was rendered uncontrollable when the unrestrained vehicle smashed through the aft pressure bulkhead and destroyed components of the hydraulic systems and horizontal stabilizer drive.
The 747 pitched up, stalled, rolled into a rapid descent and exploded when it struck the ground in a nose-down and nearly wings-level attitude. All seven crewmembers were killed in the crash, which was captured on the dashboard-mounted video camera of a vehicle travelling nearby.
The U.S. National Transportation Safety Board (NTSB) investigation of the April 29, 2013, accident concluded that the probable cause was the air cargo airline’s “inadequate procedures for restraining special cargo loads, which resulted in the loadmasterâ…
