Long thread running in the R&N part of Pprune.
Horrific....the theory that cargo broke loose and moved aft looks plausible...horrific....
As a previous Cargo pilot myself one of the more dreaded scenarios was shifting weight. We never flew that sort of cargo and not the same mass, but nonetheless, a shift to the rear is a potential killer in any cargo plane, even a small one. Safety nets always did their job for me though.
My thoughts go to their families.
What would a pilot do in case of load shift? Are there procedures? How would you try to recover?
What would a pilot do in case of load shift? Are there procedures? How would you try to recover?
There is absolutely nothing you can do. Nothing at all. For some time, I flew cargo with a Metroliner, an ugly long thin aeroplane with smallish control surfaces (also known as "San Antonio sewage pipe"). Weight and balance was crucial and any major load shift (or miscalculation) would have led to non-recoverable situations.
Once you hit the stop of any control surface, you have done what can be done. If you have a low or high thrust line, you can try adding or removing power, but usually the momentums generated by power changes are small compared to those achieved via control surfaces (they must be!).
As above, there really isn't anything you can do if your cargo ends up at the back of the plane, it'll be so far out of balance. One solution is to stuff the cargo area full (while maintaining balance) and this happened on a number of occasions when flying large volumes of small and not so heavy stuff. When flying the opposite type of cargo make sure you strap it down!
Then again, with sufficient altitude and diligent piloting it may be possible to recover after the stall if the aircraft heads down nose first and the cargo shifts forward again, ie restoring the balance.
Chances are the cargo comes out through the cockpit window instead making it an equally bad day.
I remember one trip in my Cessna where I crawled back to the baggage compartment of the (fully loaded) plane to fetch something and the AP pushed the yoke to the end of its travel. I was aware that this would happen and it was in FL150 but still impressive.
Once you hit the stop of any control surface, you have done what can be done
I get your drift, but surely that is not all you can do - IF you have height to play with (which these people didn't have).
Among the many post-AF447 speculations, one pilot worked out (in a full motion sim) that one could quickly recover from the stalled condition by rolling the plane onto its side (which may have to be done with yaw, if the ailerons are no longer effective), which would immediately make it speed up, and then you would have some seconds to recover the situation before exceeding Vne, but at least you are again flying.
Presumably the same could be applied to a 747 loaded way aft of the envelope, because control surfaces become more effective at a higher speed? I guess somebody would have to be very quick on the trim, to get the THS wound forward. I recall that AF447 would also not have been recoverable unless the THS was found forward.
