Cargo Crash at Bagram
Join Date: Apr 2013
Location: Earth
Age: 50
Posts: 152
Likes: 0
Received 0 Likes
on
0 Posts
Sometimes I hate social media because in the end, maybe two posts out of a hundred are even in the ballpark, and maybe one in a thousand actually illuminates.
Those that can't see a classic departure stall in this video either have never done one, or just fly by the numbers and got hired to read checklists.
It's easy to see the pilot working the rudders, that when the right wing broke, he came out wings level, which belies that he didn't spin it in, because he must have added power to get some air over the wings. Hence why I think it was a derate departure, stall, maybe the slats retracted...notice the gear still down? Never got positive rate? At that altitude?
Even if the cargo shifted, the aircraft pancaking in wings level belies that if power was added early they might have been able to forstall a stall to begine with.
Let's hear it for derated power to save engines. Such a great thing.
Those that can't see a classic departure stall in this video either have never done one, or just fly by the numbers and got hired to read checklists.
It's easy to see the pilot working the rudders, that when the right wing broke, he came out wings level, which belies that he didn't spin it in, because he must have added power to get some air over the wings. Hence why I think it was a derate departure, stall, maybe the slats retracted...notice the gear still down? Never got positive rate? At that altitude?
Even if the cargo shifted, the aircraft pancaking in wings level belies that if power was added early they might have been able to forstall a stall to begine with.
Let's hear it for derated power to save engines. Such a great thing.
Never flown a 747-400F but deeply involved in aviation safety issues. Following the twenty plus pages of discussion on this sad event I’m really stunned that this topic is spinning around and around an initial preconception of „load shift” or C.G. problem thrown in for our attention by somebody at a very early stage. After this momentum everybody’s mind is focused on this scenario.
You can't begin to stifle discussion by stating that they haven't finished the investigation far enough to release more data.
It's the investigators job to keep the public aware of new developments that could have a bearing on continued airworthiness.
I agree that not every nuance has to be prematurely released, but at least at regularly scheduled status briefings (we haven't had one yet?) the updates need to at least address major Hypothesis with facts , not opinions
Join Date: Feb 2004
Location: Australia
Posts: 1,307
Likes: 0
Received 0 Likes
on
0 Posts
Regarding incorrect loadings for takeoff:
Whilst the 744F does have a warning for incorrect trim settings, it does not warn you if your trim is set for an aft CG and the aircraft CG is *very* far aft. However, assuming the Weight & Balance Computer was functioning on that flight, a visual comparison with load sheet CG would have alerted the flight crew to any anomalies.
Also, as previously mentioned, the load was the same and only fuel levels were changed. Sorry if I've missed a previous post, but what would have been a typical fuel load for this flight (and, in the absence of an HST, would CWT fuel actually push the CG forward, rather than additional wing fuel pushing the CG further aft?
Whilst the 744F does have a warning for incorrect trim settings, it does not warn you if your trim is set for an aft CG and the aircraft CG is *very* far aft. However, assuming the Weight & Balance Computer was functioning on that flight, a visual comparison with load sheet CG would have alerted the flight crew to any anomalies.
Also, as previously mentioned, the load was the same and only fuel levels were changed. Sorry if I've missed a previous post, but what would have been a typical fuel load for this flight (and, in the absence of an HST, would CWT fuel actually push the CG forward, rather than additional wing fuel pushing the CG further aft?
You can't begin to stifle discussion
Occam's razor can be applied only on two hypotheses equally well explaining the occurrence and we don't have a single feasible one because so far we know next to nothing about the crash. We know that aeroplane crashed following the stall on initial climbout and that's about it. We have no idea whether cargo shifted yet we have ellaborate suggestions about cargo securing by folks who never dealt with cargo. We have no idea of power that was developed yet we got a call for crusade on derated power (well it's bloomingly obvious the author has no clue about derated vs reduced power). We have no idea of stabilizer and control positions yet we have analysis putting 747 firmly in realm of propeller driven aircraft with post stall maneuverability on par with X-31.
I guess it's PPRuNe as usual.
Join Date: Dec 2010
Location: UK
Age: 68
Posts: 103
Likes: 0
Received 0 Likes
on
0 Posts
Flyable or not?
Sadly, I'm not a pilot.
After reading through this entire thread it strikes me that the primary question is whether at any point after leaving the ground this aircraft was actually sufficiently controllable to recover it? That question can't be answered until the investigation reports.
I can see that rolling to 90% of bank will get the nose down, and why, but a 747 can't fly at 90% of bank. I can imagine a misconfiguration or control problem resulting in an aeroplane which can remain in the air in a tight turn with steep bank but pitches up to stall again when the wings are levelled. How would you get such an aeroplane back onto the ground?
After reading through this entire thread it strikes me that the primary question is whether at any point after leaving the ground this aircraft was actually sufficiently controllable to recover it? That question can't be answered until the investigation reports.
I can see that rolling to 90% of bank will get the nose down, and why, but a 747 can't fly at 90% of bank. I can imagine a misconfiguration or control problem resulting in an aeroplane which can remain in the air in a tight turn with steep bank but pitches up to stall again when the wings are levelled. How would you get such an aeroplane back onto the ground?
Nemo Me Impune Lacessit
Join Date: Jun 2004
Location: Derbyshire, England.
Posts: 4,091
Received 0 Likes
on
0 Posts
preconception of „load shift” or C.G. problem thrown in for our attention by
somebody at a very early stage. After this momentum everybody’s mind is focused
on this scenario
somebody at a very early stage. After this momentum everybody’s mind is focused
on this scenario
Not unreasonable really, within an hour of the crash it was reported that the crew made a transmission that referred to cargo shift. That transmission has not been denied.
Mistrust in Management
Well said Iron Duck
Your assumptions are correct if we believe the accident was due to an aft C of G, presumably due to a load shift.
Airclues has hinted at the same thing.
If you need 70 degrees of bank to keep the aircraft from stalling at that moment in time then you are toast very shortly after.
Airclues has hinted at the same thing.
If you need 70 degrees of bank to keep the aircraft from stalling at that moment in time then you are toast very shortly after.
Join Date: Jul 2003
Location: Austin, Texas, USA
Posts: 55
Likes: 0
Received 0 Likes
on
0 Posts
I have in the back of my mind a DC8F crash caused by a rock/stone (?) jammed between the elevator/Stab during taxy-out control checks due "FOD" by the engines. On departure they could pull back, but not push forward.
It turned out that during depot maintenance a wrench had been left in the tail cone and glued in place for a year by that yellow anti-corrosion paint. The wrench got lose and jammed in such a way that the pilot could pull back on the stick, but not forward.
That's why when I saw this horrible video my first thought was some sort of flight control malfunction.
Join Date: Jan 2008
Location: Atlanta, GA, USA
Posts: 349
Likes: 0
Received 0 Likes
on
0 Posts
photo analysis
Someone mentioned that determining the attitude of the aircraft was "simple trigonometry". Well it most certainly is not simple. These cameras have a wide field of view and there is tremendous curvilinear distortion, particularly in the corners and edges. Of course it can be analyzed with knowledge of the camera's focal length, plate scale etc. But it is not simple.
Join Date: Jan 2008
Location: Atlanta, GA, USA
Posts: 349
Likes: 0
Received 0 Likes
on
0 Posts
Don't know if this has been mentioned, but in the dashcam video, the aircraft is already recovering from what appears to be a significant right bank when it comes into view. This becomes a left bank, then another catastrophic right bank and total stall.
Join Date: Jan 2008
Location: Atlanta, GA, USA
Posts: 349
Likes: 0
Received 0 Likes
on
0 Posts
This is interesting
Expert looks at 'confluence of circumstances' in Bagram crash - CNN.com
There may not be a tactical departure as such for the 747, but there is surely a "cowboy climb" to get up and out of Dodge as fast as possible.
Expert looks at 'confluence of circumstances' in Bagram crash - CNN.com
There may not be a tactical departure as such for the 747, but there is surely a "cowboy climb" to get up and out of Dodge as fast as possible.
Join Date: Jul 2009
Location: Not far from a big Lake
Age: 81
Posts: 1,454
Likes: 0
Received 0 Likes
on
0 Posts
Was that the Phantom departing KSTL?
The St Louis Phantom still belonged to the factory, but was intended as a replacement for one lost by my Squadron. Believe that was a control linkage disconnection.
Originally Posted by exeng
If you need 70 degrees of bank to keep the aircraft from stalling at that moment in time then you are toast very shortly after.
The key question is, at what AOA did the aircraft want to fly? If it was greater than stall AOA for that configuration (including crew pushing the yokes to the forward stop), and no more flap was available, then the situation would be absolutely unrecoverable. If the resulting configuration could be flown at less than stall AOA, then possibly a temporary recovery could be finessed, provided the crew immediately recognized the severity of the problem and then promptly rolled the aircraft to get the nose down. All that would do is buy time to either correct the pitch up problem or to at least minimize it.
Just a few observations on the loading aspect..
The planks as used in the picture look dodgy,,It is more common to have several long planks stacked in alternating directions. For this applications It would have been better to have used wooden-beams, at least 6 x 6.
Aircaft holds like the 747F are ULD systems, the cargo is loaded into an 'Unit Load Device' (pallet or container) which is then loaded on the airplane. The aircraft floor has rollers/rails which spread the load onto the aircraft frame. The standard pallet is dependent on ULD lock/restraints.
Civilian aircraft take 96/88 x 125ins pallet. Military pallets are 88 X 108ins. Some aircraft have locks which can accomodate both, (I know Fedex DC10s could do this). If they loaded mil spec pallets on a civilian configured aircraft, the pallets would need to be lashed down.
For unusual items, tiedowns to the aircraft proper can be used but the limiting factor is what the floor can take in that area. On 747 it is usally highest in the wingbox area. Most positions have max wt of 6780kgs(ish) but the positions at the wing box are significantly higher. Nose and tail positions have the lowest capacity.
Coming back to the picture in the jeep, I would definitely double-check the loading and tie-down of that vehicle if it has already flown,, the potential of the planks to 'slip' during the take-off /landing is unacceptable. Consider also that it will have moved back and forth during the take-off and subsequent landings there 'will' be some slack and this needs to be checked.
Finally all the straps need to be tightened to similar tensions, otherwise the tight ones will be taking the load, leading to progressive failure.
Another thing that is easy to miss is that each tie-down location has a limit, and while you can attach several tie-downs to one fitting, they cannot exceed the limit, example you may have one strap running forward and one running to the rear, as they will never come under both forces at the same time this is acceptable. Looking at some of the pictures it is a nightmare and needs time and a systematic approach to get it done.
Not sure how the situation in Camp bastion, but this is not a 1 hour job. The fact that this is a military job and loaded by the military helps as they are generally a professional and well motivated lot with excellent equipment, but if they were working to meet crew duty-times then they may rushed it.
I don't get why some are so fixated by brakes/transmission in park. A car/truck/MRAP has limited contact area of its 4 tyres, if you are depending on four tyre 'footprints' to hold a load on a metal surface then good luck to you.
The planks as used in the picture look dodgy,,It is more common to have several long planks stacked in alternating directions. For this applications It would have been better to have used wooden-beams, at least 6 x 6.
Aircaft holds like the 747F are ULD systems, the cargo is loaded into an 'Unit Load Device' (pallet or container) which is then loaded on the airplane. The aircraft floor has rollers/rails which spread the load onto the aircraft frame. The standard pallet is dependent on ULD lock/restraints.
Civilian aircraft take 96/88 x 125ins pallet. Military pallets are 88 X 108ins. Some aircraft have locks which can accomodate both, (I know Fedex DC10s could do this). If they loaded mil spec pallets on a civilian configured aircraft, the pallets would need to be lashed down.
For unusual items, tiedowns to the aircraft proper can be used but the limiting factor is what the floor can take in that area. On 747 it is usally highest in the wingbox area. Most positions have max wt of 6780kgs(ish) but the positions at the wing box are significantly higher. Nose and tail positions have the lowest capacity.
Coming back to the picture in the jeep, I would definitely double-check the loading and tie-down of that vehicle if it has already flown,, the potential of the planks to 'slip' during the take-off /landing is unacceptable. Consider also that it will have moved back and forth during the take-off and subsequent landings there 'will' be some slack and this needs to be checked.
Finally all the straps need to be tightened to similar tensions, otherwise the tight ones will be taking the load, leading to progressive failure.
Another thing that is easy to miss is that each tie-down location has a limit, and while you can attach several tie-downs to one fitting, they cannot exceed the limit, example you may have one strap running forward and one running to the rear, as they will never come under both forces at the same time this is acceptable. Looking at some of the pictures it is a nightmare and needs time and a systematic approach to get it done.
Not sure how the situation in Camp bastion, but this is not a 1 hour job. The fact that this is a military job and loaded by the military helps as they are generally a professional and well motivated lot with excellent equipment, but if they were working to meet crew duty-times then they may rushed it.
I don't get why some are so fixated by brakes/transmission in park. A car/truck/MRAP has limited contact area of its 4 tyres, if you are depending on four tyre 'footprints' to hold a load on a metal surface then good luck to you.
Join Date: Nov 2000
Location: Sol, sector ZZ9 plural Z alpha
Posts: 80
Likes: 0
Received 0 Likes
on
0 Posts
Not unreasonable really, within an hour of the crash it was reported that the crew made a transmission that referred to cargo shift. That transmission has not been denied.
But not confirmed, either, which is much more to the point...
But not confirmed, either, which is much more to the point...
deSitter: I commented on the original roll to starboard a few pages back but it got buried under an argument about handbrakes or something, anyway I cant be bothered scrolling back through all the BS to try to find it! Somebody else commented on it before me and nobody picked up on it then either. I agree that it is an interesting thing to consider. It's very easy to disregard it - especially as you can only notice it in the moments while your brain is still going "oh look, an aeroplane" and there really isn't enough visual footage of that roll present to let it fit into one's interpretation of the events that are going on - so the load shift idea is far more compelling and the gut reaction of anybody with a grasp of flight dynamics is to conclude what everyone is saying: load shift leads to high pitch angle, then high alpha, then unrecoverable stall. This does seem like the most logical explanation for what happened and people have even resorted to the air-crash investigation expertise of William of Ockham who lived in the 12th century to defend the idea.
What interests me about the initial starboard roll, is that if you follow the sequence through to the eventual departure at TOC the motion of the aircraft in the roll axis seems phugoid, which, if that was the case, would imply an instability in roll.
It's very tenuous for several reasons: whatever is occurring in roll we assume the crew are trying to correct it, whilst at the same time possibly dealing with something else (so could merely be a side effect of that); there isn't enough video to reveal the period of the first roll; any upset in roll would be reacted to by the crew, so therefore the timings would be altered; the dashcam camera introduces its own aspect parallax as mentioned by somebody else on here.
Despite the lack of information from the video to make this idea as compelling as the load shift view, if you watch what is going on in roll closely, from that initial recovery from starboard, then to port then back to starboard at the stall, the timing of what is occurring does fit in with an instability issue.
In other words we shouldn't rule out the possibility this aircraft may have had no issues with loading at all, but may have had an unexpected instability in roll from the moment it got airborne. This could also distract the PF from calling for gear up, and with the aircraft committing most of its energy to the climb at V2+10 continued instability in the roll is going to gradually erode the forward speed in the climb, especially if the instability is absolute, leading to greater roll deviations each time, and greater forward speed deviation, exacerbating the issue into the stall.
I can hear people shouting "But what about the pitch angle" - I'm not convinced about that either. It is not as simple as people think to work this out using trig, trust me, give me a camera and I can make any one of you guys look thin. The fact is we think its a steep climb angle because it stalls and we think this must obviously be due to climb angle, which must obviously be due to load, right? By this point we already have Human Factors "Confirmation Bias" going on. Next time you are at an airport with some time to kill - go stand about a mile upwind of the departure runway and watch them go over you, then go do the same from the downwind end and watch them climb away. Regardless of your experience, without the lateral impression of climb angle these angles give you, see how often you catch yourself thinking "Wow that's steep!".
If you watched the same video and the aircraft continued off into the sunset without any drama, you wouldn't even have noticed what you thought was too high a climb angle, because your mind would have automatically compensated for the lack of information in the angle of the shot.
That's enough psychology, but food for thought.
Clear Prop, if we go back to the first two pages, the various eye witness accounts (which were not dashboard cam) mentioned pitch angle. This discussion hasn't just been about that vivid but incomplete video. Your point on perspective is well made.
deSitter:
You use two words there that I find hard to support from the video clip available.
1) "Significant" right bank? We don't know how much it was, the plane is just coming into view.
2) Why is that roll "catastrophic," as opposed to any other part of the departure, most of which is not on that film clip?
While the FDR should shed light on the sequence of control and attitude relationships, and AoA, that last right roll may have been related to post stall behavior, or it may be related to a last attempt by the crew to get the nose down and restore control.
I've seen both points presented with decent reasoning, and cannot rule either out based on the limited evidence available.
deSitter:
Don't know if this has been mentioned, but in the dashcam video, the aircraft is already recovering from what appears to be a significant right bank when it comes into view. This becomes a left bank, then another catastrophic right bank and total stall.
1) "Significant" right bank? We don't know how much it was, the plane is just coming into view.
2) Why is that roll "catastrophic," as opposed to any other part of the departure, most of which is not on that film clip?
While the FDR should shed light on the sequence of control and attitude relationships, and AoA, that last right roll may have been related to post stall behavior, or it may be related to a last attempt by the crew to get the nose down and restore control.
I've seen both points presented with decent reasoning, and cannot rule either out based on the limited evidence available.
Last edited by Lonewolf_50; 6th May 2013 at 15:12.
Join Date: Nov 2000
Location: Sol, sector ZZ9 plural Z alpha
Posts: 80
Likes: 0
Received 0 Likes
on
0 Posts
Lonewolf_50:
You're absolutely right, another good point. However, the eye witnesses were behind the aircraft with the same disadvantage of lateral view. The illusion would be the same from behind and if the departure appeared normal to them, they would disregard most of the information their eyes told them anyway, up to the point where the aircraft started doing unfamiliar things. Any instability in roll at the point of departure might be completely undetectable to a distant bystander, but quite obvious to the crew "uh oh what's wrong with my ailerons?"
The illusion is exaggerated by a camera - which is the permanent record here, but it still applies to the Mk.1 eyeball at those angles.
I'm not in any way refuting the load shift hypothesis, the point is we don't have enough information to conclude anything from the facts we've seen and heard so far, which is hopefully what the investigation will clarify, but having spotted this alternative analysis of the events as they appear, I thought I should share it.
Clear Prop, if we go back to the first two pages, the various eye witness accounts (which were not dashboard cam) mentioned pitch angle. This discussion hasn't just been about that vivid but incomplete video. Your point on perspective is well made.
The illusion is exaggerated by a camera - which is the permanent record here, but it still applies to the Mk.1 eyeball at those angles.
I'm not in any way refuting the load shift hypothesis, the point is we don't have enough information to conclude anything from the facts we've seen and heard so far, which is hopefully what the investigation will clarify, but having spotted this alternative analysis of the events as they appear, I thought I should share it.
Join Date: May 2006
Location: Scotland
Posts: 131
Likes: 0
Received 0 Likes
on
0 Posts
Let us ask this:
If not load shift, then what else could cause a fairly modern aircraft to stall and crash on take off?
Runaway trim seems to be ruled out due to how the 747-400s systems work to prevent or rectify such automatically.
So, what could cause such an upset that would make the crew believe they were dealing with a load shift, if indeed they reported such. So far no official source has refuted claims that the crew radioed such a message. But the absence of a denial does not mean confirmation either.
If not load shift, then what else could cause a fairly modern aircraft to stall and crash on take off?
Runaway trim seems to be ruled out due to how the 747-400s systems work to prevent or rectify such automatically.
So, what could cause such an upset that would make the crew believe they were dealing with a load shift, if indeed they reported such. So far no official source has refuted claims that the crew radioed such a message. But the absence of a denial does not mean confirmation either.