Turkish airliner crashes at Schiphol

[Hot 'n' High]

Did not really want to post here but just have to agree with Rainboe [Post 427] and Lost in Saigon [Post 441] re Dani’s Post 343.

Dani, while I agree with your analysis – that only holds water IF the aircraft was fully stalled – the word fully being vitally important. Indeed, what you describe at post 343

normaly stalling first over the wings, it falls into a spiral and the wing impacts first

describes very accurately the evolution of an incipient spin at very low level, leading, eventually, if not corrected and if sufficient height exists, to a fully developed spin (basic PPL stuff here!). But, as we all know, most aircraft are designed to stall incrementally, the stall starting at the wing roots and working outboard as angle of attack is progressively increased. A stall is not an on-off condition; it is a progressive condition – which is not what you erroneously suggest. Engineers design aircraft specifically in that way to look after us pilots and give us a chance to sort things out before the aircraft is fully stalled

As we all know, when an aircraft is partially stalled, generally from the wing root and extending outboard as the angle of attack increases, it exhibits increasing drag and decreasing lift which starts to become insufficient to support the aircraft mass, thus leading to an increasing ROD. The further towards the fully stalled condition, the lower the lift generated, and the higher ROD. Therefore, in a partially stalled condition, you have a higher ROD than normal, but not in the realms of that which you allude to, a value whereby the crush damage on impact is total and catastrophic.

If, and it is an “if” as I would hate to prejudge things here, this were a stall-induced early "touchdown" in the undershoot, the aircraft would probably only be partially stalled with a lower than normal airspeed (hence groundspeed hence shortish groundslide), higher than normal ROD and an unusually high pitch angle leading to the tail impacting first. Once the tail started to drag, aerodynamics would fade, and pure mechanics would start to take over. Effectively the airborne mass of the aircraft would “reduce” as more and more weight is taken by the increasing amount of fuselage in contact with the ground. Ground friction drag would start to rapidly rise leading to an increasingly rapid clockwise moment causing rotation (when viewed from stbd) leading to pitch-down motion along with increasing deceleration. I’ll let you take the simple mechanics through the final seconds. By the time the cockpit reaches the ground, forward velocity would be very much reduced while the pitch-down moment would have reached it’s greatest – ignoring any forces dissipated by engine pods breaking off etc, etc.

Anyway, hope this provides a scenario of what may have happened here. Whatever happened, for whatever reason – another sad day in aviation (sorry Rainboe – H ‘n’ H is a bit of a softy at heart! I know you hate it!!!!!)