Green Room

Horrendous: Cargo plane crashes in Afghanistan

posted at 4:00 pm on April 30, 2013 by

Via Danger Room, this really is the stuff of nightmares. Watching it feels like a nightmare.

What happened? A theory:

Some early reports are saying the crew mentioned the cargo had shifted. That’s a much more likely reason for the stall than pilot error. A mechanical problem with the flight controls, in particular the elevator trim known as a “runaway trim” is another, though less likely scenario.

Any airplane must be carefully loaded to maintain the center of gravity within a carefully designed and tested zone of the airplane. Cargo aircraft are always loaded so light things are far away from the “CG” and heavier things are closer to the CG. If the cargo inside the 747 were to break loose during take off, it would slide towards the tail, dramatically shifting the center of gravity to the back of the airplane. This would cause the nose to rise dramatically, and without sufficient power to overcome the extremely high angle of attack (the angle between the wing and the flow of air), the air flowing over the wings would “detach” from its normal flow, causing a stall where the wings can no longer generate enough lift to keep the airplane airborne.

All seven people aboard are dead.

Update: The previous clip won’t load, so here’s another version from XBRADTC.

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Awful, and my prayers go out to the families. Rearward CG shift is usually a very bad thing in a cargo aircraft.

Ward Cleaver on April 30, 2013 at 4:10 PM

Heartwrenching.

Logus on April 30, 2013 at 4:16 PM

The article says the crash happened yesterday but the date stamp on the video is February 1st. Any explanation?

youknowit on April 30, 2013 at 4:22 PM

Thoughts and prayers to the families…horrible.

trs on April 30, 2013 at 4:25 PM

The article says the crash happened yesterday but the date stamp on the video is February 1st. Any explanation?

youknowit on April 30, 2013 at 4:22 PM

It was shot with a dashcam, so it may be that the owner’s never set the date and time. But it was definitely yesterday. Here’s the accident description on ASN, my go to site for such things:

http://aviation-safety.net/database/record.php?id=20130429-0

Ward Cleaver on April 30, 2013 at 4:28 PM

The video was stomach turning.

Prayers for the crew’s families.

She was a pretty aircraft.

cozmo on April 30, 2013 at 4:34 PM

Why does this guy have an antenna on the front of his car?

(As to the date/time, it also says it’s 3am, apparently. So, I go with the “never set” answer.)

Depending on how much of the capacity is used, a weight shift shouldn’t do this. CG is important, but there are safety margins. You shouldn’t be able to load the airplane in such a way as to set the CG outside safe parameters unless you’re loaded to your limit. For a “weight shift” to do this would require a pretty drastic shift. (Though, with a radical climbout, the shift required is less. I don’t see any reason for a radical climbout at this airport.)

I am going to go with an aerodynamic surface issue. When it stalls out, the tail doesn’t remain down as I think it would if the weight had shifted dramatically aft. Instead, the aircraft rolls off to one side, and settles into a neutral pitch and tips forward normally to recover airspeed after its stall. One of the problems with a CG too far aft is that it prevents that normal stall recovery. It is possible the cargo shifted forward – but that would mean there had to be enough aerodynamic authority to push the plane over to start with.

I think it was runaway trim, or a pilot outperforming the aircraft. At first blush, anyway. (I’ve seen this happen up close, as I watched the Fairchild bomber pilot practice the year before his crash, and had walked inside the squadron after watching his “manuevers” just before he *did* crash.)

GWB on April 30, 2013 at 4:49 PM

Prayers for the crew’s families.

She was a pretty aircraft.

cozmo on April 30, 2013 at 4:34 PM

Cozmo, this plane caught my eye at the beginning of April as it sat on the ground at the Fresno Airport for 10 days. It was a very pretty aircraft. Very striking livery.

I have a picture of it as it took off on 4/18/2013. I followed it on Flightaware up until yesterday.

Thoughts and prayers to the family and friends of the flight crew.

ehlerts on April 30, 2013 at 4:54 PM

I retract my statement about not needing a radical climbout – this is Bagram. Duh. Everything else stands.

GWB on April 30, 2013 at 4:57 PM

Wind shear could explain it. Cargo handlers are professional, and it would take a LOT of cargo shifting to upset a 747. The video looks like a classic stall.

There was a thunderstorm in the area and the wind shifted from a near-direct right crosswind recorded before takeoff to a quartering left crosswind recorded after the crash. If the wind backed through the southern quadrant, the pilot would have had to deal with a tailwind on takeoff. Not a good thing.

skydaddy on April 30, 2013 at 5:18 PM

The video was stomach turning.

Prayers for the crew’s families.

She was a pretty aircraft.

cozmo on April 30, 2013 at 4:34 PM

Awful to watch as we knew what was coming. Thanks for the link of her in better times.

arnold ziffel on April 30, 2013 at 5:56 PM

A similar accident happened with a cargo plane at MIA, back in the late 90s. Really awful.

SWLiP on April 30, 2013 at 6:02 PM

Looks like he’s at too steep an angle. Saw a DC-8 freighter in Nashville do that once. Fortunately, the pilot dropped the nose enough to avoid a complete stall.

rickv404 on April 30, 2013 at 6:24 PM

Just saw the video……

horrible tragedy……I weep for the victims and their families.

ColtsFan on April 30, 2013 at 6:57 PM

Prayers for the victims and their families.

dogsoldier on April 30, 2013 at 7:05 PM

The plane was obviously in an extreme stall, just by looking at the pitch attitude in the video. I don’t want to second guess anything, but the Taliban claim that they shot it down is ludicrous. An improperly loaded plane, combined with an incorrect weight and balance calculation is much more likely, but a runaway shift in onboard cargo is also not out of the question if the ULD containers were not locked down properly. I have no idea who National Air Cargo is, but by looking at their website, they look very small with a bunch of very old airplanes, and rely on contractors to handle their ground operations. If the flight data recorder is recovered, and the NTSB is brought in, we may find out eventually what happened here. But in Afghanistan, who knows.

“Forget about it Jake, it’s Chinatown”, might be what happens to this accident.

simkeith on April 30, 2013 at 7:15 PM

I hope it wasn’t sabotage… I have a bad feeling about this.

ITguy on April 30, 2013 at 9:26 PM

Awful.

Whoever was in that car had to have a moment wondering exactly where that plane was coming down.

TexasDan on April 30, 2013 at 9:40 PM

BSBD.

No way you should see the profile of a 747 shown at the 5 sec mark that close to the ground. It was a high angle of attack takeoff b/c it was Bagram and cargo broke loose (or was not properly restrained to begin with) which caused rearward cargo shift beyond aft CG limits. Not a heck of a lot can be done to recover at that point.

climbnjump on April 30, 2013 at 11:04 PM

c

limbnjump on April 30, 2013 at 11:04 PM

That’s the only thing I can think of. You would not expect pilots to just stall out even with a full cargo.

lexhamfox on April 30, 2013 at 11:33 PM

The article says the crash happened yesterday but the date stamp on the video is February 1st. Any explanation?

youknowit on April 30, 2013 at 4:22 PM

It also says it’s 3:30am. Obviously it’s not.

Ronnie on April 30, 2013 at 11:48 PM

everyday is February 1st on Bagram…

oprockwell on May 1, 2013 at 1:43 AM

ULD containers

simkeith on April 30, 2013 at 7:15 PM

Reportedly the cargo was not just ULDs, but also 5 “military” vehicles destined for Dubai.

If the military vehicles were “high density”, i.e high mass per unit volume due to heavy armor or other reasons, I can envision one vehicle breaking loose for some reason on the extreme climb-out, and possibly cascading into the other vehicles in a domino-like effect.

That’s just just my pure rank speculation, but CG shift and resulting too high AoA was the first thing that popped into my head when I saw the video.

Difficultas_Est_Imperium on May 1, 2013 at 2:04 AM

everyday is February 1st on Bagram…

oprockwell on May 1, 2013 at 1:43 AM

Or April 1st.

bigmacdaddy on May 1, 2013 at 6:13 AM

The aircraft had no groundspeed, it fell almost straight down. It was a failure of forward speed rather than a failure of airspeed. If the crash was due to tail windshear, the aircraft would have still been travelling over the ground at its 150mph takeoff speed. Also, the gear is still down and locked. Whatever happened, happened as soon as the plane left the ground and occupied the pilots before the gear up call.
This airfield is at 5000ft, could a mistake in ft/meter in the takeoff data have screwed things up that much? Did they lift the nose early to avoid something on the runway? Who knows.

tdarrington on May 1, 2013 at 7:20 AM

The aircraft had no groundspeed, it fell almost straight down. It was a failure of forward speed rather than a failure of airspeed. If the crash was due to tail windshear, the aircraft would have still been travelling over the ground at its 150mph takeoff speed.

tdarrington on May 1, 2013 at 7:20 AM

Well, not quite… It is airspeed that matters. Ground speed is irrelevant to flight. What is the ground speed of kite flying in a stiff March breeze?

climbnjump on May 1, 2013 at 9:23 AM

That looked just like a straight-up stall. Not enough airspeed and way too steep attack angle. Could be from a CG shift, could be from trim or control issues, we’ll have to wait for the blackbox data to tell for sure.

I’ve had this happen to me while flying my RC plane FPV style. I had the CG set a tiny bit too far back. Not enough to make the plane unflyable, but enough to make it touchy. I was already airborne, tooling along at about 100 feet, slowed down so I wouldn’t fly too far too fast and went to adjust the trims a bit. In the process I pulled back on the elevator a bit too much, lost airspeed and spiraled into the ground. It was almost shocking how quickly it happenned and how rapidly I lost any control over the aircraft as the wings lost lift.

Of course, in my case all I had to do was straighten out the squished foam nose of my plane with some boiling water, repaint and go fly again. Much worse for a real plane. (Which is why I fly toy ones. Nobody dies when I crash, which happens far more frequently than I’d like.)

wearyman on May 1, 2013 at 9:31 AM

This seems more likely than the cargo shifting forward.

blink on April 30, 2013 at 5:06 PM

I meant after the initial pitch up. In order to get the nose to pitch back forward at the end, the cargo would have had to shift back forward. That would have required a violation of the laws of physics, though.

everyday is February 1st on Bagram…

oprockwell on May 1, 2013 at 1:43 AM

Ain’t that the truth….

With the low groundspeed and high AOA, it might very well have been shear. You take away the airspeed suddenly, and it stalls out. And there’s nothing the crew can do at that altitude, though they (the pilots anyway) were probably frantically trying. :(

GWB on May 1, 2013 at 9:57 AM

Given that most of the guys are from Michigan, I suspected if the cargo contained vehicles. It appears so -

http://www.nationalaircargo.com/

It is plausible that some fastener gave way and a vehicle rolled to the back of the plane.

sram on May 1, 2013 at 10:41 AM

Hold up, everyone.

MSNBC isn’t convinced the plane actually crashed.

Actual headline: “Terrifying plane crash purportedly caught on camera”

Those MSNBC guys are sharp.

BobMbx on May 1, 2013 at 10:42 AM

Awful.

dpduq on May 1, 2013 at 10:58 AM

Seeing how Bagram airport is surrounded by mountains, planes have to takeoff steeply to begin with. Word from friends is that there were RESET vehicles along with assorted freight on board. Typically the vehicles would be HMMWVs and MRAPs and they can weigh as much as 40k pounds each. One breaking loose can set a chain reaction, but I’m still leery since such a scenario would possibly have the vehicles crash thru and out of the plane before it even hit the ground. Not to dismiss that a couple could have broken loose but restrained by other loads and distracted the crew just enough in the critical seconds to lose the flight envelope.

AH_C on May 1, 2013 at 11:59 AM

Well, not quite… It is airspeed that matters. Ground speed is irrelevant to flight. What is the ground speed of kite flying in a stiff March breeze?

climbnjump on May 1, 2013 at 9:23 AM

No kiddning…but airplanes still have speed over the ground when they are flying. A 50mph tail windshear would still leave the plane travelling 100mph+ over the ground. This was not.

The CG of planes is forward of the wings, which when combined with the horizontal tail, would make the plane naturally fall nose down. The plane had very little airspeed, so the elevators would be ineffective to correct the pitch up if the cargo broke free and slid aft. The plane would have crumped in tail first. My guess would be that they had the pitch trim set incorrectly for the CG, which caused the plane to over rotate on takeoff and stall. The aggressive climbout the pilots planned only made it worse. The plane lost forward speed and airspeed, then freefell with the nose pitching down naturally and the right wing tipping down due to minor right/left imbalance. At the last second, the pilots had enough aileron authority to level the wings, but not enough airspeed to create lift.

tdarrington on May 1, 2013 at 2:16 PM

There’s an unfortunate graphic on nationalaircargo.com’s website. You’ll know it when you see it.

CrustyB on May 1, 2013 at 2:17 PM

Are you thinking that the nose wouldn’t have hit first if the CG had shift aft?

blink on May 1, 2013 at 1:54 PM

Exactly. If it had changed enough to make the plane unflyable, the aircraft would have continued to wallow tail-down, instead of going into a natural stall recovery (that pitch down at the end is the plane naturally trying to regain airspeed to continue flying).

The plane lost forward speed and airspeed, then freefell with the nose pitching down naturally and the right wing tipping down due to minor right/left imbalance. At the last second, the pilots had enough aileron authority to level the wings, but not enough airspeed to create lift.

tdarrington on May 1, 2013 at 2:16 PM

Actually, the slight dip of one wing, followed by the radical drop of the other is a classic sign of a stall. It doesn’t require any “imbalance” at all. The pilots didn’t level the wings at the last second, the wings naturally leveled because they were just starting to pick up airspeed in order to fly again.

A 50mph tail windshear would still leave the plane travelling 100mph+ over the ground. This was not.

tdarrington on May 1, 2013 at 2:16 PM

No. On a radical climbout (required not so much by the mountains as by the Taliban around Bagram) the groundspeed is minimal. A huge portion of your velocity vector is oriented up. Especially with full flaps. On top of which – his groundspeed matters not at all to his staying airborne. I’ve flown a small aircraft at almost 0knots groundspeed before, and have seen aircraft actually move backwards relative to the ground, because of a headwind. (And, yes, we were flying at approach airspeed and such, not normal cruise; and we were at altitude with plenty of recovery space below us.)

Also, if he was moving at 100knot indicated airspeed suddenly, then he was at least 50 knots too slow to stay airborne. That is why he crashed – not enough airspeed.

As a note – this plane had flaps down full and it appeared the gear were down (at least partially). He was NOT going that fast. I hope he didn’t plan/set the wrong climbout speed for the load he was carrying. :(

GWB on May 1, 2013 at 3:50 PM

Cessnas are not the same as 900,000 pound 747s taking off at a 5000 ft airfield. His “radical climbout” would have been 3-400ft/ mile. We are not talking about a vertical climb fighter jet, it is more of an 18-wheeler. I mention groundspeed as a reference to horizontal momentum, which should have still been significant if it was a tailwind cutting the air out from the wings. My guess is that they had the pitch trim set for the wrong center of gravity. It doesn’t take much for that big horizontal stabilizer (the entire horizontal tailplane tilts for trim) to outstrip the elevator authority at low airspeed. The plane over rotated, and the pilots couldn’t keep the nose down. It would have seemed like the load came loose and slid to the back, because it is tough to imagine you made an error in setting the flight controls. Having been in a similar situation (with a better outcome by a hair) in a C5, the first thing that goes through your mind is “Damn loadmasters!”

tdarrington on May 1, 2013 at 6:31 PM

It would have seemed like the load came loose and slid to the back, because it is tough to imagine you made an error in setting the flight controls. Having been in a similar situation (with a better outcome by a hair) in a C5, the first thing that goes through your mind is “Damn loadmasters!”

tdarrington on May 1, 2013 at 6:31 PM

Reminds me of a lesson learned tale in a Air Force mag (can’t recall the name, but had a regular cartoon character “Fleagle”) Mid-80s, a C5 pilot was recounting how he almost lost his bird at Howard AFB, Panama on takeoff. Plane refused to rotate as expected and at the last second, he realised the trim was set at, IIRC -11%, and he was able to retrim as she lifted and barely cleared the trees. He too was blaming the loadmasters at first. LOL

AH_C on May 2, 2013 at 12:04 PM