Follow-up: Bagram Air Base 747F Crash - Stall on Departure

[sardak]

This is a follow up to the now closed thread on the 747 freighter that crashed on takeoff from Bagram Air Base: http://www.captalk.net/index.php?topic=17322
Link to the video of the crash (the one in the thread is dead): https://www.youtube.com/watch?v=-MB9JDBe4wA

The crash occurred in Afghanistan, so the Afghan government had the responsibility for the investigation. Instead, Afghanistan turned the investigation over to the NTSB, which just released its docket of factual information obtained during the investigation, but it has not yet published the probable cause.   http://dms.ntsb.gov/pubdms/search/hitlist.cfm?docketID=57043&CFID=470429&CFTOKEN=71331616

The primary load was five Mine Resistant Ambush Protected (MRAP) vehicles, two weighing 28,000 lbs each, loaded as forward most and aft most, and three 40,000 lb units in between them. From the Flight Data Recorder (FDR) analysis:
"The FDR data show a normal takeoff was performed from OAI (Bagram), but just after lift-off, the FDR recording stopped [as did the cockpit voice recorder at almost the same moment] with the airplane approximately 33 feet above the ground. Video of the airplane (see link above) just after liftoff at a low altitude over the runway shows an extremely high pitch attitude before experiencing a stall and impacting the ground at a nose-down pitch attitude. The available FDR data, Cockpit Voice Recorder (CVR) data, and physical evidence (video, airplane component analysis), with additional support from simulation analysis, suggest that around lift-off, at least one MRAP (aft-most) broke loose of its restraints, shifted aft and damaged the FDR/CVR before penetrating the aft pressure bulkhead. The MRAP's aft movement was determined to have compromised at least Hydraulic Systems #1 and #2 (of four) and may have contacted the stabilizer jackscrew assembly." http://dms.ntsb.gov/public%2F57000-57499%2F57043%2F567192.pdf

The imprint of the rear mounted spare tire of the MRAP was on the ruptured bulkhead, and there was orange paint, similar in color to that on the FDR and CVR on the MRAP. The FDR and CVR were located in a compartment between the MRAP and the bulkhead. An NTSB analysis could not positively conclude the orange paint was the same. The CVR (and FDR) stopped just after the crew made the call sequence of V1, rotate, positive climb and gear up. Pieces of the airplane were found on the runway well before the impact point.

After landing at Bagram on the inbound leg, the crew is heard on the CVR talking about a load strap breaking and some shifting of cargo. The sections of the NTSB report on the whole process of how the aircraft was loaded are interesting to say the least. 

Mike 

[JeffDG]

I remember when I saw the video, my first thought was load-shift and way out of envelope aft CG.

[Live2Learn]

I remember when I saw the video, my first thought was load-shift and way out of envelope aft CG.

+1

The video is a painful reminder of how weight and balance works.  Visual, visceral, and graphic.

[JeffDG]

I remember when I saw the video, my first thought was load-shift and way out of envelope aft CG.

+1

The video is a painful reminder of how weight and balance works.  Visual, visceral, and graphic.

Especially when you consider that the flight crew on that plane knew, basically from the moment the load broke loose, that their aircraft, with them on it, was doomed.  As soon as the nose went up and full forward deflection didn't change it, they knew they were going to crash very soon.

[SarDragon]

There's a video out there of a Navy C-2 doing essentially the same thing after a carrier launch. It had an aircraft engine a ship size generatorin the cargo area, which broke loose, and did the aft CG trick. No one made it out of that one, either. 15 December 1970.

https://www.youtube.com/watch?v=OlDmMwI9cik

[PHall]

Who in the heck secures large rolling stock like a MRAP with straps anyway?  That's why you have 10,000 pound and 25,000 pound tiedown chains.
And I'm willing to bet that they didn't protect those straps from the sharp metal edges like you find on the tie down points on vehicles like the MRAP either.
Not saying that it made a difference, but unlike regular military airlift aircraft like the C-5 and C-17 which carry the loadmasters that load and unload the aircraft, the folks who loaded and secured this cargo on this aircraft were not flying on this aircraft.
It's amazing how having your own life in your hands makes you much more careful on how you do your job!

[SarDragon]

I was wondering about chains versus straps, too. Each has pros and cons.

[sardak]

The MRAPs were chained to pallets. NTSB document #31, Operations Attachment 30 - Bastion Loading, has pictures of the loading of the pallets on this flight, but not of the pallets strapped down. The pallets though, can't be chained to the plane, so straps are used to secure the pallets. Discussion and photos about that here http://www.pprune.org/rumours-news/513650-cargo-crash-bagram-34.html

Photo from that link, NOT of the accident plane.


Mike

[PHall]

Pallets do not need to be chained to the aircraft. The pallet restraint rails provide all of the restraint required. (9g forward without barrier net/1.5g forward with barrier net, 2g up and 1.5g left/right and aft.)
An MRAP is longer then a single pallet so a two pallet train is required. Pallet couplers link the pallets together. This is not rocket science...

The picture shown above shows the vehicles NOT loaded on pallets. This is "bare floor" loading with the sleeper shoring under the rear axle differentials.

[Flying Pig]

Crazy deal... I was on that plane about a month before the crash. 

[a2capt]

What fun Sheriff's Dept. stuff got moved?

[Flying Pig]

They were held over at our airport for a couple weeks so we would go over and walk around inside of it. 

[PHall]

Pallets do not need to be chained to the aircraft. The pallet restraint rails provide all of the restraint required. (9g forward without barrier net/1.5g forward with barrier net, 2g up and 1.5g left/right and aft.)
An MRAP is longer then a single pallet so a two pallet train is required. Pallet couplers link the pallets together. This is not rocket science...

The picture shown above shows the vehicles NOT loaded on pallets. This is "bare floor" loading with the sleeper shoring under the rear axle differentials.
I would have serious reservations about the way this load has been secured with nothing but straps. Straps under tension are pretty easy to cut and those straps going through the bare vehicle tiedown points with no protection is a strap failure looking for a place to happen...

[N Harmon]

One of the crew members on that flight was a CAP member assigned to my squadron.

[abdsp51]

Saw the video shortly after it happened at work.  Hopefully it's used by the AF for the loadmaster tech school to show what can happen when a load shifts.