National Airlines B747-400 Freighter Crash (R/W) - 4/29/2013

[Covert53]

A U.S.-based National Airlines B747-400 freighter on presumably a military charter crashed after taking off from Bagram AB in Afghanistan earlier today. Cause is undetermined/unannounced at this time but enemy combat action has been ruled out. 7 souls perished. It's sad when any aviator perishes but it's a bit more so when civilian aviators die in a combat zone in service to their country. Story link here: http://aviation-safety.net/database/rec ... 20130429-0

[esurfman]

Incredible....http://www.youtube.com/watch?v=79FXTA2K40g Must have been horrifiyng.

[nwadc10]

Yes, horrific. Looks like they didn't have a chance. Looking at the video, and this is pure speculation on my part, it seems that load came loose and rolled to the back of the cargo hold. A couple theories are that the plane was loaded out of CG to begin with or that circumstances required a very steep departure procedure.

I would be surprised if it was loaded out of CG to begin with. I'm sure the cargo load master is experienced and may have been aided by computers to make sure the load was within limits...having never operated cargo flights this is an assumption and surely the crew had to verify the CG through their company procedures as is required for every flight.

A steep departure causing the accident, while could be a factor, I don't think is the cause either. A steep departure is protected by the stall protection system of the aircraft. When reaching a specified AoA the stall warning would trigger, continued increase of the AoA would trigger the stick pusher. All this occurs before the aircraft actually stalls, under normal circumstances. It is possible to pitch up so rapidly that the stall protection system cannot react fast enough to prevent a stall.

Finally, the theory of the cargo load coming loose. On the ground the CG checks out within limits. The G force of acceleration and rotation for liftoff causes the load to loosen and roll to the back of the hold, now CG is way out of limits. So far out of limits that neither the crew nor the stall protection system (stick pusher) have enough authority (leverage) to pitch the nose down. When the CG is that far back, there is no chance.

Again, this is speculation on my part. I have no experience operating cargo flights, no meaningful experience with the type of aircraft, nor am I any kind of an accident investigator. This is just what my eyes saw when viewing the video and I usually turn out to be wrong.

As a professional pilot that video is difficult to watch but when the investigation is complete I hope myself and other professional pilots may learn from what happened here. May those who were onboard rest in piece.

[Brogs]

I think if he had had a bit more altitude he may have recovered, he seemed to level and then pancake into the ground, poor guys

[E6BAV8R]

Yes, horrific. Looks like they didn't have a chance. Looking at the video, and this is pure speculation on my part, it seems that load came loose and rolled to the back of the cargo hold. A couple theories are that the plane was loaded out of CG to begin with or that circumstances required a very steep departure procedure.

I would be surprised if it was loaded out of CG to begin with. I'm sure the cargo load master is experienced and may have been aided by computers to make sure the load was within limits...having never operated cargo flights this is an assumption and surely the crew had to verify the CG through their company procedures as is required for every flight.

A steep departure causing the accident, while could be a factor, I don't think is the cause either. A steep departure is protected by the stall protection system of the aircraft. When reaching a specified AoA the stall warning would trigger, continued increase of the AoA would trigger the stick pusher. All this occurs before the aircraft actually stalls, under normal circumstances. It is possible to pitch up so rapidly that the stall protection system cannot react fast enough to prevent a stall.

Finally, the theory of the cargo load coming loose. On the ground the CG checks out within limits. The G force of acceleration and rotation for liftoff causes the load to loosen and roll to the back of the hold, now CG is way out of limits. So far out of limits that neither the crew nor the stall protection system (stick pusher) have enough authority (leverage) to pitch the nose down. When the CG is that far back, there is no chance.

Again, this is speculation on my part. I have no experience operating cargo flights, no meaningful experience with the type of aircraft, nor am I any kind of an accident investigator. This is just what my eyes saw when viewing the video and I usually turn out to be wrong.

As a professional pilot that video is difficult to watch but when the investigation is complete I hope myself and other professional pilots may learn from what happened here. May those who were onboard rest in piece.

Word from a friend of mine that is somewhat "in the know" says they believe a certain 15 Ton vehicle became dislodged on departure.

[jcwaugh747]

This is very tragic, it appears to be a repeat of a crash of a DC-8 in the 90's. Load shift on rotation. Most of the cargo carriers used to practice a maneuver for that scenario, though I think that practice went by the wayside.

Would not be surprised to see people start training for it again.

In a cargo plane it is always a bit concerning to have a heavy load with a lot of open floor space, such as when hauling large vehicles or equipment that can easily move on their own.

I will play with FSX to see if we can create a scenario for our crews to practice for such an event.