DETROIT — Federal transportation officials say a military vehicle aboard an overloaded plane in Afghanistan broke free, likely leading to the 2013 crash that killed all seven crew members.
The National Transportation Safety Board said Tuesday an improperly secured Mine Resistant Ambush Protected vehicle went through the bulkhead. It disabled two hydraulic systems, rendering the aircraft uncontrollable.
The Dubai-bound Boeing 747-400 plane was operated by National Air Cargo Group Inc. when it crashed just after takeoff from Bagram Air Base on April 29, 2013. The crash killed six crew members from Michigan and one from Kentucky.
NTSB officials found “critical safety deficiencies,” including a failure by National Air Cargo, which does business as National Airlines, to restrain cargo. It found inadequate Federal Aviation Administration oversight of cargo operator procedures and inspector training.
The Associated Press left a message seeking comment from National Airlines.