This animation shows what may have happened aboard the Boeing 747 that crashed after take off from Bagram

May 01 2013 - 17 Comments

The following video shows what may have caused the crash of a National Air Cargo Boeing 747-400 shortly after take off from Bagram Airfield, in Afghanistan, on Apr. 29.

As we reported on our first article on the accident, there are rumours that radio frequency monitors listened a crew report according to which the load had shifted just prior to the crash.

Bagram crash animation

A sudden and violent shift of the CG (Center of Gravity) during initial climb, might have induced the impressive nose high attitude that is clearly visible in the shocking video recorded by a car dash camera.

At that speed and altitude, the aircrew could do nothing to recover the situation.

The animation below points towards the engine stall as the root cause of the crash; however, the wings stalled (they would stall even if the engines were working properly) and the aircraft almost fell from the sky like a stone.

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  • R.Lopaka

    The engines stalled……Ignorant media strikes again.

    • BadgerMk1

      Agreed, if you don’t know what you’re talking about, please refrain from talking about it. Of course, that never stops people.

    • Dragon029

      Engines can and do suffer from compressor stall.

    • Hug H

      The wings stalled… ignorant commenter. You can hear the engines screaming before impact.

    • Joe V

      With the airplane at such an abnormally high nose up attitude it’s possible that the flow of air into one or more engines was inhibited. This causes the flow of air going backwards through the compressor to momentarily stop or even reverse, however the compressor itself doesn’t stop rotating. The engine will momentarily lose power, sometimes you will hear a popping sound and flame will sometimes come out the front of the engine. Occasionally a severe enough compressor stall can cause a flame-out.

      It’s more likely here that the load shifted causing the plane to go nose up. The compressor stall(s) were secondary effects. Unlike a fighter plane the intakes on a 747 are not designed to take in air at a high angle of attack like this plane experienced.

  • Nightcomer

    Terrible :/

  • Nicholas Martin

    I am now dumber having seen that…

  • WonderingGeologist

    Engines don’t stall, wings do. Idiot.

    • cencio4

      Actually, engines stall. More correctly, they suffer compressor stalls when airflow at the air intake is disrupted.
      Here you can find a description of that kind of stall:
      http://theaviationist.com/2011/08/22/flameout/

    • Dragon029

      Wrong, engines can have compressor stalls, which this plane would have been vulnerable to in that vector.

  • http://ideiasvazias.tumblr.com/ Tiago Jeronimo Lopes

    Would just one vehicle be enough to cause a critical change in the CG?

    • A sad loadmaster

      30,000 pounds, which is roughly the weight of an MRAP, would indeed be enough, particularly the load was already toward the aft end of the CG envelope. I don’t know where it was for this aircraft, but I ran some numbers and found that in some cases, as little as 1 vehicle shifting only 6 feet was enough to throw it out of limitations. With a CG load right in the middle of the envelope, 15-20 feet could.

  • M

    The correct term for a compressor not getting enough air to operate correctly is called surging. symptons of surging: loud bangs, violent vibrations, loss of power.

  • pilot ron

    the engines didn’t stall. they were at full power. the wing stalled.

  • BigD

    Classic nose high aerodynamic stall. One wing will always stall first (down wind wing usually) and the plane will roll that direction. The reason for the nose high attitude will take the cvr and dfdr to be analyzed to be sure. The Emery dash 8 that crashed the same way out of Mather airfield in Sacramento was initially called a cargo shift but they found that improperly installed bolts on the control rods was the cause. Most cargo planes are loaded slightly aft CG anyways for fuel savings (less drag) so if it was load shift it didn’t take much to be out of limits. If the pilots don’t react fast enough (and what pilot would instinctively put full nose down stick on takeoff) then it was too late.

  • loodaufo46

    i think the cargo is the cause of the crash the plane stall when its nose was very hi and maybe he shutdown the engin to prevent the hi climb and try to liviling the plane agine after all i think the pilot did all he can to avoid the crash but the ground was very near to him

  • AF guy

    I was there for this (several of my coworkers were on that jet before it took off as well). Was a really bad day. The engines didn’t stall out, the pilot actually gunned the engines to get his air speed up because one of the MRAPs it was carrying broke loose and went the the back of the jet and caused a COG shift. We think it got loose while the jet was rolling down the runway. After the investigation, they bulldozed the site and put all the steel into a pile and gave it the the Afghanis for scrap.