National Air Cargo 747 Crash at Bagram

[jango220]

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

Tried doing that in the sim the other day (-135s), and it was a no-go. Our sim is apparently limited in what it can do for rapid CG shift. Basically tried to simulate a body tank check valve failure - a possibility with a MPRS or RT jet - with forward body gas moving aft, starting a ~26% CG moving to 40+ rapidly. Only way the sim instructor could attempt it was to move around the gas manually on his panel. For some reason the software couldn't keep up, it would freeze everything and retrim the sim.

[Clayton Bigsby]

Cargo straps for MRAPs...UFB. I never used anything less than 25K chains and devices.

[Hacker]

Cargo straps for MRAPs...UFB. I never used anything less than 25K chains and devices.

There are several shots found on Google of MRAPs inside Atlas jets that are secured with cargo straps.

I'm just a pointy nosed dude and know nothing about securing cargo loads...but it is there in the photos.

Edited May 4, 2013 by Hacker

[Jbirdd]

There are several shots found on Google of MRAPs inside Atlas jets that are secured with cargo straps. I'm just a pointy nosed dude and know nothing about securing cargo loads...but it is there in the photos.

Jesus that is scary, no freaking chains!? Those are some weak ass looking straps, remine me never to work for these dudes in my next life. I wouldn't get on that jet.

[LockheedFix]

Those should be in the WTF thread. You pay $250M for a jet and then scrimp on your method to secure the load it carries. How much could a few 25K chains cost?

[fou]

Could be the tie-down points are the limiting factor. I wonder what each of those rings is rated to? If those rings were only rated to say 2k lbs, it wouldn't really be useful to have 10k/25k chains strapped to them. Just a thought.

[arg]

Could be the tie-down points are the limiting factor. I wonder what each of those rings is rated to? If those rings were only rated to say 2k lbs, it wouldn't really be useful to have 10k/25k chains strapped to them. Just a thought.

Nail on the head.

[TacAirCoug]

There are several shots found on Google of MRAPs inside Atlas jets that are secured with cargo straps.

I'm just a pointy nosed dude and know nothing about securing cargo loads...but it is there in the photos.

Those look like 5000# straps on the top pic. It looks like there are at least 6 on the front alone, at least another 4-8 down each side, & who knows how many on the aft end. I'm no loadmaster, but that actually looks fairly adequate to me. I agree that chains would be better (and would make me a whole lot less nervous), but the number of chains required for 5 MRAPs would add quite a bit of weight.

Could be the tie-down points are the limiting factor. I wonder what each of those rings is rated to? If those rings were only rated to say 2k lbs, it wouldn't really be useful to have 10k/25k chains strapped to them. Just a thought.

Good point.

[Jbirdd]

Nail on the head.

How would you like to figure applied restraint on those spaghetti balls of straps?

[Prosuper]

[arg]

How would you like to figure applied restraint on those spaghetti balls of straps?

No thanks. Those look like a gunner tied them down.

Big fail I see is straps going across sharp edges. When those straps get pulled tight they are easy to cut.

[sky_king]

Of the 10 straps or whatever are attached to the front of the MRAP in that picture, 8 of them are securing the load side to side. I'm not a load master, but I did take Physics 101 in college and I know that this will not provide any restraint fore/aft. It looks like only 3 or 4 straps are able to apply any fore/aft force at all. Heck, they may have well let a SERE specialist go in there with a mile of 550 cord.

[Jbirdd]

No thanks. Those look like a gunner tied them down. Big fail I see is straps going across sharp edges. When those straps get pulled tight they are easy to cut.

Not only that but at the front of the vehicle in the one photo there appears to be more than a couple of straps giving very little if any restraint.

Anyway you slice it that is a farked up load imho.

[fou]

Of the 10 straps or whatever are attached to the front of the MRAP in that picture, 8 of them are securing the load side to side. I'm not a load master, but I did take Physics 101 in college and I know that this will not provide any restraint fore/aft. It looks like only 3 or 4 straps are able to apply any fore/aft force at all. Heck, they may have well let a SERE specialist go in there with a mile of 550 cord.

From looking at those pictures, you are right, there doesn't look to be many straps providing AFT restraint.

*Assuming they(National Cargo or other contractors) use the same restraint criteria as the AF, the minimum for AFT restraint is 1.5x cargo weight. So for the MRAP, you would need roughly 60k worth of AFT restraint. If you could get all the required restraint from these straps (5k straps???) and maybe an average of 60% of that applied to each strap that was giving AFT restraint, it would require 20 straps alone just for AFT restraint. If somehow those straps and tie-downs were good for 10k, then only 10 straps for AFT.

*Edit-My numbers apparently are off from overestimating MRAP weight.

Edited May 5, 2013 by fou

[Oo7kerpow]

Don't forget it's at an angle up-so the horizontal component is less then what the strap is rated at. So for a 10000 pound strap, you might only get 2/3 of that

Edited to show that it might have already been covered at 60%

Edited May 5, 2013 by Oo7kerpow

[Bergman]

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.

Perhaps there has been more than one T-1 incident. I know the IP from the Laughlin jet that it happened to, and he was with a fairly new female student. They heard a loud "clunk" on initial takeoff and he subsequently put it in 60 degrees of bank for several minutes to keep the nose down while he figured out what to do. Pretty funny (now) to imagine a 500' closed pattern in a T-1 over base housing.

[Prosuper]

What it looks like on a C-17.

Now on a 747

[lloyd christmas]

From looking at those pictures, you are right, there doesn't look to be many straps providing AFT restraint.

*Assuming they(National Cargo or other contractors) use the same restraint criteria as the AF, the minimum for AFT restraint is 1.5x cargo weight. So for the MRAP, you would need roughly 60k worth of AFT restraint. If you could get all the required restraint from these straps (5k straps???) and maybe an average of 60% of that applied to each strap that was giving AFT restraint, it would require 20 straps alone just for AFT restraint. If somehow those straps and tie-downs were good for 10k, then only 10 straps for AFT.

*Nerd talk from a former load

On the Herc, you need at least 3.0 Gs forward, 2.0 vertical, 1.5 for aft and 1.5 lateral. So if you have a 28K MRAP you would need 84K lbs of forward restraint, 56K vertical and 42K for aft and lateral. We use 10K tiedown fittings, chains and devices but because of the angle you usually get around 7500lbs per chain/device. It is possible to use straps but like someone said earlier, they are subject to tearing especially when under that much tension and when run over a sharp edge. What is also interesting to note in those Atlas pictures is some of the straps are not attached using a ratchet. They look like they are just tied into the ring on the floor. It is not easy to tie a knot and keep tension on it when restraining cargo.

[XL0901]

I'm not familiar with the cargo system on a 747 but in that config, do those pallets even lock to the floor??? Looks like the straps are the only thing keeping it from sliding around.

[Fuzz]

I'm not familiar with the cargo system on a 747 but in that config, do those pallets even lock to the floor??? Looks like the straps are the only thing keeping it from sliding around.

I'm not seeing any logistics or ADS rails but then again it's a little hard to see between the 69 straps attached to the MRAP

[Alpharatz]

I just pulled some cargo straps used on a commercial semi.......2 inches X about 1/16th material unknown rated at 1000lbs shackles are hefty....hooks 3/8th's steel...pretty sure the sewing would give first...web sling tie down assoc. rated (you've heard of them) .......I have never ever seen a cluster #### of a cargo load as in those pix...The DOT would pull a semi over and beat the driver (after they got done laughing) for "securing" a load like that.....my first question would be what if you had to really nose over? Would those straps stretch....let the MRAP float up? Loosen up? BUT...I admit total speculation.....leave it at that due to "third degree of separation"

........................................................Safe skies to all crew dogs.......................................

[F16Rooster]

I used to load mail containers on 747's, 727's, and DC-10s. The containers were held in place using metal flip up stops. Does the floor in question have those same stops? Pretty sure I can see a couple of them but that doesn't mean that they're useful for that load. Just a thought. I know nothing of securing loads in military aircraft or MRAPS specifically.

[Kaman]

I have a theory about the cargo handling system failing...I cannot speak to what the G-ratings and Fight envelope the systems limitations are, but there were reports of LLWS in the area. In fact, there was reports of the wind gusting to 42 knots when they landed from the previous leg. It could be possible that they had a LLWS upset that might have caused an already faulty or incorrectly loaded pallet to fail and then create a pitching moment that put the rest of the load out of limits and it too failed? VERY sad no matter what the findings, it was a young crew and a good friend of mine's buddy was one of the F/Os that was killed.

[kchsload]

Tie-down straps on MRAPS would never happen on AF jets, we weren't even supposed to use them for 7,500lbs HUMVEEs in the air-land world. The only items I recall using straps were on crew luggage, helos and small loose items like tow bars or engine stands. On the -17 we pulled out the 25k chains without even thinking about it for cargo like MRAPS, maybe some 10k chains for supplemental restraint.

In the pics above they have straps going around what looks like some kind of mount in front of the side view mirror, no way they're getting much vertical restraint out of that, looks like it would snap off if it actually came under serious stress that a MRAP's weight could put on it.

On the Herc, you need at least 3.0 Gs forward, 2.0 vertical, 1.5 for aft and 1.5 lateral. So if you have a 28K MRAP you would need 84K lbs of forward restraint, 56K vertical and 42K for aft and lateral. We use 10K tiedown fittings, chains and devices but because of the angle you usually get around 7500lbs per chain/device. It is possible to use straps but like someone said earlier, they are subject to tearing especially when under that much tension and when run over a sharp edge. What is also interesting to note in those Atlas pictures is some of the straps are not attached using a ratchet. They look like they are just tied into the ring on the floor. It is not easy to tie a knot and keep tension on it when restraining cargo.

Same requirements in the C-17, but we use 25k chains and figure getting roughly 18,500lbs of restraint out of it .

Edited May 5, 2013 by kchsload

[Clayton Bigsby]

Benefit to the C-17, all the tiedown hooks on the floor are rated to 25k. Oh, and the pallet locks are strong, probably a lot stronger than anything in a 747. Speaking of, is the 463L pallet anywhere close to the same dimensions as a regular commercial 747 pallet? 463L measures 108"x88"...

It's funny, really your biggest limitation in how many vehicles your plane could carry wasn't so much how to space them in, it's how to get them in and have room between the vehicles to get the proper restraint. Yeah, you can go under a vehicle with the chains provided no more than 50% of the restraint goes to the axles and provided it sits high enough for you to get in there to do what you need, oh and that you have the time to do all this and not have your balls busted about takeoff times...but to have all that go hand in hand is rare. So you end up with wasted space between vehicles where all the chains go.

Anyway to me, snap judgment from the 747 payload pics, it just looks like somebody thought more of 'how many of these can we cram in?' than 'hey, how good is our restraint here?'