Turkish airliner crashes at Schiphol

[paparomeodelta]

The pilot was screaming

One of the passengers tells TV-station:
"All of a sudden the captain starts screaming ojojojojojoojoj, I thought it was a joke, but then the plane fell down..."
Link:
Utredare granskar olycksplats | Utrikes | SvD

[Dani]

Well well, DC-ATE again. Go back to your MS Flight Sim!

FE hoppy, the 88kts come from a ADS transponder read out which is clearly not correct. It most probably measured the average speed during touchdown shortly before stopping.

Can someone of you guys give me an explanation why and how an aircraft could stall, then slide on more than hundred meters and still everyone survives? There is simply no known accident of a stalled aircraft where someone survived.

I take bets in any currencies...

Dani

[Aeroengineer1]

European Commission says Turkish Airlines has good safety inspection results

"European Commission VP and Commissioner for Transport Antonio Tajani said in a statement that "in 2008 Turkish Airlines underwent 100 ramp inspections. The results for safety and security have always been good." THY completed its IATA Operational Safety Audit in April 2006. It was renewed in November 2007 through November 2009."

From: ATW Daily News

[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!!!!!)

[Marsh Hawk]

I would like to pose a question to the experts: how instrumental was the muddy field in increasing the survivability of this accident? It seems to me that the yielding dirt cushioned the vertical forces just enough to make this accident survivable for most.

[TRC]

Engine stall

I think the term 'stall' used in the context of the statement is a dumbing down for the benefit of the non-aviation public.

I doubt if it refers to 'compressor stall', more like the stalling of a car engine.

[Rainboe]

...................

[fireflybob]

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.

I always understood that at the stalling angle of attack the wing was generating MAXIMUM lift (or Coefficient of Lift more accurately, CL)! Beyond the stalling Angle of Attack CL starts decreasing. Throughout this drag is increasing.

Jet aircraft on the approach are usually speed unstable as approach speeds are less than minimum drag speed. Of course if you let the speed get really low full thrust won't accelerate the a/c since drag is greater than the thrust - you then have to lower the nose, decrease the angle of attack and get some speed back - this presupposes you have sufficient height to do so.

Not saying this is what happened on this accident but it could be a factor.

[fyrefli]

As no-one else has provided the requested re-translation of van Vollenhoven's original Dutch, I've done some reading of a few Dutch news sites. I've not found anywhere referring to stalled engines - but then I don't think anyone here thinks that was an accurate translation anyway!

I've roughly translated the following article - disclaimer - I am English but lived in Holland for five years and, unlike many, actually did bother learning the lingo to a reasonable degree!:

nu.nl/vliegramp schiphol | 'Toestel viel letterlijk uit de lucht'

"Volgens Pieter van Vollenhoven heeft de bemanning van het Turkse vliegtuig dat woensdag bij Schiphol neertstortte, geprobeerd zo lang mogelijk in de lucht te blijven."

According to Pieter van Vollenhoven the crew of the Turkish aircraft that crashed at Schiphol on Wednesday tried to stay in the air as long as possible.

''Maar als je dan snelheid verliest, dan val je letterlijk uit de lucht. Het toestel heeft ook geen lang spoor in het weiland getrokken'', aldus de voorzitter van de Onderzoeksraad voor Veiligheid in het NOS Journaal.


Quote: "But if you then lose speed, you literally fall out of the sky. The plane also didn't leave long tracks in the ground (literally meadow)." according to the Chairman of the Safety Investigation Committee / Council in NOS Journaal (one of the main Dutch TV News Programmes).

Van Vollenhoven en enkele andere deskundigen van de raad hebben de plek des onheils woensdag bezocht en zijn hun onderzoek begonnen.


Van Vollenhoven and various other advisors / experts visited the scene of the accident on Wednesday and begun their investigation.

Daar trof Van Vollenhoven een dermate grote ravage aan, dat hij ''zeer verrast'' is dat het aantal doden woensdagavond nog beperkt was tot negen.


Van Vollenhoven found there such a scene of carnage (can't quite get the nuance of ravage right myself, I'm afraid) that he is "very surprised" that the number of dead was still only 9 on Wednesday evening.

De voorzitter van de Onderzoeksraad voor Veiligheid zei in het tv-programma NOVA dat de vliegers van het toestel verpletterd zijn, toen een instrumentenpaneel achter hun rug de cockpit binnen kwam.


The leader of the Safety Investigation Committee / Council said in the TV programme NOVA that the flight crew met their death when an instrument panel came into the cockpit from behind their backs. (Note: that's what it says - "behind their backs" and "came into the cockpit"; please don't shoot the messenger!)

De oorzaak was het plotselinge afremmen van het toestel in de modder, aldus Van Vollenhoven.

According to Van Vollenhoven, the reason for this was the sudden deceleration of the fuselage in the mud.

[jupilair]

I have flown in Turkey and to be honest I have seen a lot of craps, when I say a lot it's a lot, which for sure could have end up in a field before the runway. So my bet is that the A/C has no technical deffects at all. I would be tempted to say that they lost control when they disconected the A/P. Knowing that they where three in the cockpit, I would say first flight as PF for the F/O after the type rating and no proper or too late correction of the captain. For sure it's just supposition...

[Lost in Saigon]

There are even some examples where the engines continue to run after an accident has occurred

Originally Posted by helimutt

I saw this once when an airliner crashed onto a beach. The engines continued to run and even caused a further fatality some time after initial impact. Ever since then the series of 'LOST' has gone downhill.

Here is an example of engines running after a crash......


http://www.nfpa.org/assets/files/PDF...t_Accident.pdf

When the aircraft finally stopped moving, the Captain asked for the severe aircraft damage drill checklist. As they completed the checklist, it became apparent that both engines were still at full power and they were initially unable to shutdown the left engine because the thrust lever was impaired. Meanwhile, the passengers were getting instructions from the in charge F/A to start evacuating the aircraft. Fortunately the right engine shut down by itself as the passengers exited the right overwing exit. The left engine continued to run at full power even after the fire switches were pushed. It was only after the Captain put his foot on the instrument panels and applied all of his strength, that he was able to shut down the left engine.

[SaturnV]

The four Americans who died were the four Boeing employees on the flight.

[matthieucalu]

I just heard an eyewitness on the Dutch television, who was seated just aft of the wing (seat 19F). He recounts that the airplane made some strange movements before he heard the engines rev up to full speed. He clearly stated that the pilot must have applied full power, because the engine noise was really loud. It was however too late and shortly thereafter the aircraft smashed into the ground.

This would clearly mean there was no fuel starvation and that the pilot did indeed select TOGA-power. This would also indicate that there was no problem with the engine. The theory of a/t being disengaged without the pilots knowing seems more plausible by the minute.

[wes_wall]

The more I hear the more I am beginning to think that there is a fuel issue rooted in this. Engines simply do not have compressor stalls causing fan rotation to terminate that quickly. Pictures appear to indicate little or no rotation upon contact with the ground.

[excru]

Van Vollenhoven found there such a scene of carnage (can't quite get the nuance of ravage right myself, I'm afraid) that he is "very surprised" that the number of dead was still only 9 on Wednesday evening.

Ravage: destruction

Take care

[dbx]

@ rainboe:

Look at the pictures on page 1 and 2. The tail is broken off behind the rear fuselage! Are you an experienced pilot? You cannot land a plane like this on a wet field without the gear coming off and the fuselage sliding quite a long way- not one planelength! The very rapid stop means slow speed and the damage means high ROD. Wherever are you getting these rate of descent estimates from?
They came within a whisker of not surviving.

I'm not taking a position either way, but I think perhaps Dani is saying that it actually did slide for maybe 70-80m based on the overhead photo below. When looking at SAS 751 where it slid for about 110m after striking the ground at 120knots with all surviving, the outcome in this case is indeed significantly worse but still comparable.



The similiar state of the SAS -80:

[hetfield]

@jupilair

Possible.

I must admit, I've seen a lot of crap with non standard crew composition.

Would be very interesting if there are any statistic numbers of accidents/incidents regarding non standard crew.

[Desert Diner]

If the engines were reving up just before, then why no fire? You would expect fuel all over the place under these conditions.

There must have been some tremendous g's to dig her in like this when she came down.

From the Times:

[Rainboe]

3333333333333333333333

[robdean]

Fyrefli - thanks for the translation. How about 'devastation' for 'ravage'?

H'n'H - well said...