According to Wired’s “Danger Room” blog, “A camera outside of the Bagram Air Field in Afghanistan caught footage of Monday’s horrific crash of a civilian cargo plane, which left seven people dead:”
The plane, a contractor-operated Boeing 747-400 carrying vehicles and other cargo, does not appear to be under any attack in the video. On its ascent, it’s shown pitching at a terrifying angle before unexpectedly — and terrifyingly — crashing outside the massive airbase, a major logistical hub for the U.S.’ longest war.
Pentagon officials today huddled around computers in the public-affairs office to watch the video, which appeared on YouTube and LiveLeak, while covering their mouths in astonishment and horror. The military command in Afghanistan is “looking into the authenticity of the video,” according to Navy Cmdr. Bill Speaks.
No cause of the crash has been determined yet. No missile or any other object is shown in the video approaching the 747-400. A takeoff stall is something all pilots train for regularly, especially commercial pilots, so it’s highly unlikely the accident is a result of pilot error.
The cargo load shifting within the plane is being investigated as a possible cause:
Some early reports are saying the crew mentioned the cargo had shifted. That’s a much more likely reason for the stall than pilot error. A mechanical problem with the flight controls, in particular the elevator trim known as a “runaway trim” is another, though less likely scenario.
Any airplane must be carefully loaded to maintain the center of gravity within a carefully designed and tested zone of the airplane. Cargo aircraft are always loaded so light things are far away from the “CG” and heavier things are closer to the CG. If the cargo inside the 747 were to break loose during take off, it would slide towards the tail, dramatically shifting the center of gravity to the back of the airplane. This would cause the nose to rise dramatically, and without sufficient power to overcome the extremely high angle of attack (the angle between the wing and the flow of air), the air flowing over the wings would “detach” from its normal flow, causing a stall where the wings can no longer generate enough lift to keep the airplane airborne.
“It does not appear from the video that anyone on the ground was injured, although the plane crashes near trucks on the base’s perimeter,” the Wired post adds. “Whomever shot the video — and it seems shot from a security vehicle, and an accent that sounds Australian is audible — does not scream or exclaim as the plane crashes. The video is eerily quiet; at one point, something sounding like a dog whines.”