National Air Cargo 747 Crash at Bagram

[C-21.Pilot]

Until told otherwise, I think the wise person believes that load shift is the culprit.

However, runaway trim could also be an issue....

What National is saying is that the LM/AC signed off on the Form F's and gave to ATOC, etc. This doesn't necessarily mean that the load was good. I'm sure that every once in a while somebody down below pencil whips the paperwork.

Against speculation, it'll be a very sad read if it's proven it was something that could have easily been prevented.

[Muscle2002]

Should work the same aerodynamically in a pointy, but you guys have fixed stations for weight. Fuel, believe it or not, can shift enough to affect the longitudinal stability even in small fighters (sometimes, it is kept aft for intentional departures) Move CG aft of the center of lift and horizontal stabilizers/elevators no longer have sufficient authority to maintain stable flight. Essentially, however, once the CG moves aft of the neutral point, the aircraft is by definition unstable (at least statically speaking) so we're really talking controllability vice maintaining stable flight.

Often CG is calculated within inches-feet so pushing back a part of the load a few feet can be catastrophic. Let's say you have a single large item in the back that comes loose. Aircraft pitches up during rotation and that item slides back. At worst, the result could be continued overrotation followed by an unrecoverable stall.

[Prozac]

Until told otherwise, I think the wise person believes that load shift is the culprit.

However, runaway trim could also be an issue....

What National is saying is that the LM/AC signed off on the Form F's and gave to ATOC, etc. This doesn't necessarily mean that the load was good. I'm sure that every once in a while somebody down below pencil whips the paperwork.

Against speculation, it'll be a very sad read if it's proven it was something that could have easily been prevented.

Not saying it's impossible, but there are multiple, independent systems on the 74 that would have to break for runaway trim to be the factor.

[Wolf424]

It doesn't take as much as some may think to throw CG out of limits. The center of gravity on a herk has to be kept within a very small range (a couple feet) or it's out of CG. Can't imagine a couple 40K lbs vehicles moving to the back of the plane.

[Hueypilot]

Until told otherwise, I think the wise person believes that load shift is the culprit.

However, runaway trim could also be an issue....

What National is saying is that the LM/AC signed off on the Form F's and gave to ATOC, etc. This doesn't necessarily mean that the load was good. I'm sure that every once in a while somebody down below pencil whips the paperwork.

Against speculation, it'll be a very sad read if it's proven it was something that could have easily been prevented.

I investigated a load shift mishap were the crew felt it was secure, ATOC signed it off as good and it still broke loose. They had even transited several other locations before the mishap occurred. It had more to do with the suitability of the container design than anything else but the crew in question was lucky- it broke loose on landing rollout and there were no pax.

Just because NAC issued a statement that the load was properly signed off doesn't mean it couldn't get loose.

[MXQA]

I know that run away pitch trim was a problem on KC-135s, and the Gielenkirchen (KC-135E) crash was a direct result. Has this been a current issue on B747s?

[Napoleon_Tanerite]

I know they're different aircraft, but the 707 has a stab brake that stops the trim from running if the yoke is pushed/pulled in the opposite direction that the trim is running. Given that Boeing likes design similarities where they are suitable, it wouldn't surprise me if the 747 was similarly equipped. Anyone with 747 time care to chime in?

[Hueypilot]

Most newer aircraft have the dual circuit grounded trim systems designed to prevent runaway trim...older aircraft (KC-135, etc) have a single trim circuit that easily caused uncommanded trim inputs. Even in the Herk, older E and H1 aircraft have the older system but newer H2s up thru Js have the dual circuit switches. The NAC airplane was a -400 so runaway trim is much less likely, although not impossible.

[StoleIt]

I know they're different aircraft, but the 707 has a stab brake that stops the trim from running if the yoke is pushed/pulled in the opposite direction that the trim is running. Given that Boeing likes design similarities where they are suitable, it wouldn't surprise me if the 747 was similarly equipped. Anyone with 747 time care to chime in?

Aren't 747s fly by wire?

The stab trim brake on the KC-135 is mechanical and I really hope the 747 doesn't have the same bike chain we have for trimming.

[TarHeelPilot]

Most bases besides Bagram have MOG issues especially when you super heavies on the ramp, anytime you have a A330, AN-124's, C-5's and 747's it fills the ramp quick . At OAMS we could only have one on the ramp one time when I was there last year or we parked you outside the wire on the old runway. Plus POL issues you usually only had two R-11 drivers on duty which turned a transoceanic trip fuel load into a 6 hour affair and these NAC guys knew this so they went to Bagram for a large top off. We always passed on to TACC our POL limitations and of course I had better luck trying to get a pig to sing.

Thanks for the explanation-- it made no sense reading the company statement that they were enroute from Bastion to Dubai and stopped at Bagram for fuel.

[Whitman]

Until told otherwise, I think the wise person believes that load shift is the culprit.

However, runaway trim could also be an issue....

I'm not a 747 guy but if it were a runaway trim issue wouldn't it have been nose DOWN runaway (obviously not shown in the video) because of the trim inputs from the flight deck with an increase in speed?

I believe the KC-135 Class A that killed everyone on board was runaway nose UP because they were on approach and trimming nose up as the airspeed decreased. I don't know, I'm not a doctor.

[M2]

On a related note, from the AFA Daily...

Aircraft Mishaps Now Top Cause of US Deaths in Afghanistan

As combat operations wind down in Afghanistan, aircraft accidents have become the main cause of combat-related deaths among US military personnel there, reported McClatchy. Of the 33 US lives lost since the start of the year, 13 have been in five aircraft crashes, including the four airmen who were killed on April 27 in the crash of an MC-12 surveillance airplane near Kandahar Airfield, according to the news service. The four other crashes involved an F-16, Apache attack helicopter, Black Hawk helicopter, and Kiowa reconnaissance helicopter. Among the remaining deaths, eight came from improvised explosive devices, four from small arms fire, two from indirect fire, and six more from some other means, including two so-called "green-on-blue" attacks, states McClatchy's April 30 report. The latter are cases in which Afghan security forces suddenly turned their guns on US forces. In related news, a commercial 747 cargo airplane under contract to the Defense Department crashed on April 29 while taking off from Bagram Airfield, killing the seven civilian crew members.

[afnav]

On a related note, from the AFA Daily...

Aircraft Mishaps Now Top Cause of US Deaths in Afghanistan

As combat operations wind down in Afghanistan, aircraft accidents have become the main cause of combat-related deaths among US military personnel there, reported McClatchy. Of the 33 US lives lost since the start of the year, 13 have been in five aircraft crashes, including the four airmen who were killed on April 27 in the crash of an MC-12 surveillance airplane near Kandahar Airfield, according to the news service. The four other crashes involved an F-16, Apache attack helicopter, Black Hawk helicopter, and Kiowa reconnaissance helicopter. Among the remaining deaths, eight came from improvised explosive devices, four from small arms fire, two from indirect fire, and six more from some other means, including two so-called "green-on-blue" attacks, states McClatchy's April 30 report. The latter are cases in which Afghan security forces suddenly turned their guns on US forces. In related news, a commercial 747 cargo airplane under contract to the Defense Department crashed on April 29 while taking off from Bagram Airfield, killing the seven civilian crew members.

Wow. Thanks for posting that quote.

Safety stand down in 5, 4, 3...

[CHQ Pilot]

Have a friend that flies -400s for another cargo operator and he believes it was highly unlikely it would have been a trim runaway. Some of the points he stated was that the trim moves relatively slowly in the -400. The greenband for the trim is set from the nosegear strut extension for each takeoff. If the trim was set outside the greenband, then they would have gotten a takeoff config warning. If the trim ran away after V1, the stab moves too slowly for it to put the aircraft in the position it was. He said it may be "possible", but many different systems would have to fail simultaneously in order to have a mistrimmed or runaway trim condition. He thought, like a lot of people, a possible load shift or some other unknown catastrophic failure of the aircraft in the pitch control.

[Prozac]

Aren't 747s fly by wire?

The stab trim brake on the KC-135 is mechanical and I really hope the 747 doesn't have the same bike chain we have for trimming.

400s aren't FBW. The new -8s have some FBW controls. See Huey's explanation of modern trim systems above.

Have a friend that flies -400s for another cargo operator and he believes it was highly unlikely it would have been a trim runaway. Some of the points he stated was that the trim moves relatively slowly in the -400. The greenband for the trim is set from the nosegear strut extension for each takeoff. If the trim was set outside the greenband, then they would have gotten a takeoff config warning. If the trim ran away after V1, the stab moves too slowly for it to put the aircraft in the position it was. He said it may be "possible", but many different systems would have to fail simultaneously in order to have a mistrimmed or runaway trim condition. He thought, like a lot of people, a possible load shift or some other unknown catastrophic failure of the aircraft in the pitch control.

This.

[disgruntledemployee]

While my experience of runaway trim has been simulator only, they were noticed, counter-acted, and controllable.

That video and description of the crash really fits sudden CG shift to the tail, such as a heavy rolling vehicle breaking loose when the plane rotates a solid 10 degrees nose up for take off, then probably increasing to 15 degrees once airborne. Sudden CG shift is something that we don't practice in the sim.

Capt Sully made a remarkable landing in the river and I believe he was able to do so because he thought about it and perhaps even practiced it in the sim. While cargo breaking free on takeoff doesn't happen often, this accident higlights that danger and if we try to practice recognizing it and recovering from it, we might have a fighting chance. I really hope the company is able to recover the FDR and CVR and can show us what the plane was doing and what the crew tried to do to recover.

My next trip to the sim will include a shift in CG if they can set it up.

Out

[Vertigo]

I've seen supposed pictures of the cargo. If the pictures are of the actual load it would be not surprise to me the cargo shifted.

The MRAPs in the pictures I saw were secured using commercial cargo straps (mind you these vehicles weigh about 28K each). Just by looking at them I wouldn't rate them any higher than 1000 pound straps each... not the 5K straps we use. They looked pretty damn thin in the pictures.

[C-21.Pilot]

Saw the same pics with the blue "cheap straps". Didn't initially put 2+2 together.

[Napoleon_Tanerite]

While my experience of runaway trim has been simulator only, they were noticed, counter-acted, and controllable.

That video and description of the crash really fits sudden CG shift to the tail, such as a heavy rolling vehicle breaking loose when the plane rotates a solid 10 degrees nose up for take off, then probably increasing to 15 degrees once airborne. Sudden CG shift is something that we don't practice in the sim.

Capt Sully made a remarkable landing in the river and I believe he was able to do so because he thought about it and perhaps even practiced it in the sim. While cargo breaking free on takeoff doesn't happen often, this accident higlights that danger and if we try to practice recognizing it and recovering from it, we might have a fighting chance. I really hope the company is able to recover the FDR and CVR and can show us what the plane was doing and what the crew tried to do to recover.

My next trip to the sim will include a shift in CG if they can set it up.

Out

The problem with doing it in the sim is you know it is coming. Even if you don't know exactly when they are going to hit the button you know it's in the profile. I'm not a cargo dude, but I would imagine that the time between "hey something ain't right" to an unrecoverable situation is measured in seconds if that long, especially if it isn't accompanied with any other indication other than an odd control response (or lack thereof).

[Fuzz]

when a cargo shift happens isn't the time to think about what will/might work. who cares if you know bits coming, that's what the Sim is for to practice so when the "oh shit" factor kicks in you know what you need to do.

[GrndPndr]

<snip>

My next trip to the sim will include a shift in CG if they can set it up.

Please excuse a question from an ignorant but curious person:

In the simulator, I wonder if you will be able to see how much CG shift can be countermanded with control inputs (elevators/stabilizers fully deflected), i. e. is the airplane even recoverable at near max TO weights? Also, can one maintain enough energy is to keep flying under these conditions? Maybe it can be simulated by moving fuel aft?

My apologies if I should not be asking questions like this. I am not looking for numbers, I am just curious if it is possible.

FM

[fox two]

I am pretty sure a full on CG shift way out of limits would be impossible to recover from no matter how many times you practice it in the sim. Only theoretical way to regain control is to move the cargo or move the wings, both impossible in this situation. MAYBE the plane could be put in a bank so instead of stalling straight up you are pulling a constant turn, but even then you're stuck in a giant slip attitude and probably aren't landing in one piece. The only situation I've heard of that recovery being used for is if the elevator control cables break and the elevator falls to a constant pitch up position (I believe it happened in a T-1 and instructors only practice this in the sim).

[XL0901]

As mentioned, the effects of runaway trim and sudden aft CG shift are different in reaction time and total affect on the ability to stay airborne, but after doing a planned (and per-briefed) full nose up trim condition in the sim, I feel that in the moment I would at least start the necessary corrections (get slow with a shit-ton of bank). Of course this doesn't mean it would be successful and I would effectively just fly to the crash site, but to discount this training is a foul. At the very least it promotes discussion and puts the ideas in th back of your nugget that under certain circumstances may save your life; at least more so than never talking about it in the first place.

Now to what really matters...Godspeed to the crew and anyone affected. It's been a tough week for all. Fly safe and check six

[mcbush]

The only situation I've heard of that recovery being used for is if the elevator control cables break and the elevator falls to a constant pitch up position (I believe it happened in a T-1 and instructors only practice this in the sim).

Heard about this T-1 incident last year. Just like you said, the elevator failed full up on takeoff. Luckily, it was two IPs flying rather than a student sortie. They were able to bank the aircraft enough to maintain a controllable airspeed and managed to make a safe landing out of it.

[Kaman]

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