Turkish airliner crashes at Schiphol

[samolyot]

Out of interest, for any non-Dutch speakers, The Dutch press are reporting a representative from TALPA blaming wake turbulence due to a 757 which landed earlier. The Dutch VNV is denying this, saying that a 2 min margin is normal

nu.nl/algemeen | 'Ander toestel mogelijk oorzaak crash'

Haven't seen this report mentioned in the English speaking press

[Belgique]

Think G stall

Low-level stall cause? The clues are scattered throughout the posts. Time somebody gave it a name.

1. fully configured at 3nm in approx. 1000ft with F30 and being distracted by heavy training on the flight deck on final approach, speed starts dropping and nobody realises.

2. the issue with the autothrottle seems plausible -
fully configured at 3nm in approx. 1000ft with F30 and being distracted by heavy training on the flight deck on final approach, speed starts dropping and nobody realises that the A/T is off. aircraft gets upset.....

3. The appch looked fairly normal until 600ft (09.25.08Z), in regards to glide path and speed.

4. I`d speculate that something odd happened just afterwards, as the speed starts to decay. I see the following happening: Down to 600ft all working well and aircraft being flown with A/P and A/T engaged. Shortly afterwards, around 500ft the automatics are disengaged and for some unknown reason(s) proper speed management was not maintained, or maybe they assumed the A/T was still engaged when it was not. The mistake was only noticed very late down the approach and they were caught without options on a low energy/low altitude scenario. Perhaps they even tried to initiate a GA (some survivors stated a sudden increase in engine power shortly before impact, if I recall correctly ) and hit the tail in the process.

5. Witnesses on the ground describe nose high attitude, followed by a dive to the ground.

6. The aircraft hit the ground tail first in a high rate of descent with low forward speed. This is obvious from the photos of the crash scene.

When the FDR and CVR information is released, I expect that it will confirm a low altitude stall, or approach to stall, with an incorrect or incomplete stall recovery.

See this linked image
.
In the 15 seconds between 09:25:23 and 09:25:38 UTC, at around 350 to 400ft agl, soon after breaking cloud, and with Auto-throttle not obliging with any drag-opposing thrust, the aircraft stick-shaker would have cooked off and the surprised pilot would have disconnected the autopilot and selected an SOP max-power, yet immediately encountered the fierce zooming effect of low-speed max power pitchup. However combined with that nose-up couple, at autopilot disconnect, additionally and fatally, courtesy of the insidious effect of auto-trim, he'd have also unexpectedly liberated a yoke-full of max elevator backtrim and nose-up stabilizer. That he would have been then pushing and fighting that powerful nose-up pitch couple would be without question. But, before we consider what happened next, what would the F/O have been thinking when he saw the nose pitch up? Would he (could he?) have understood what was happening? Think of that Egyptian Captain returning to the cockpit of Egyptair 990 and seeing the suicidal Batouti seemingly fighting for control. In the very short time available, would the Turkish captain have been able to communicate the nature of his problem? Food for thought, what action might the F/O take? helpful or not? ..... but back to the instant pitch-up....
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Ever tried a very nose-high power-on stall? Few pilots do this as an exercise, and if they did, then they'd better do it at height. Why? Because at the point of stall the nose pitches down to an alarming "face full of dirt" attitude (which you'd only appreciate as you rebroke cloud again). What happens next? Well you have a very limited height in which to recover from the ensuing dive - but because of the ground-rush phenomena, believe me when I say that you will be trying very hard. Low-level aerobatics pilots will know how disciplined you have to be to recover from a misjudged low-level pitching plane nose-low maneuver, in order to avoid going beyond buzz, buffet, judder into the g-stall .... and then performance destroyed, into the dirt. Performance with gear and flap down will be marginal, even with max power.
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When you g-stall due to a panic-stricken pitch-rate, you kill the lift vector at a speed well in excess of the one g stall speed, no matter where the LE and TE flaps are. I need no further convincing that TK1951 had made it most of the way around the bottom when the ground intervened.... and the tail departed and the cockpit was then counter-pitched down, very hard, into terra firma.
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What needs to be determined is when and how (or why?) the auto-throttle became disconnected or disabled. Radar altimeter spikes? CB pulls? A large municipality's RF interference with that RADALT? A new high-zap directionally aimed terror weapon designed to interdict vulnerable auto-land systems? Or was it simply a directive or decision to demonstrate to the trainee a manually throttled approach (which was then overlooked by ingrained habit patterns?).
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Has anybody ever practised this nasty in a simulator as part of a recognized syllabus? I doubt it. We do these things to ourselves - but with the able assistance of automation.

[Green Guard]

Above or Below GP

the approach above the glide in IMC is a recipe for disaster due to the false glide scenario and the increased descent angles involved.

Whether to capture it from Below or from Above in IMC, it still can be a recipe for disaster if Distance to Threshhold is not veryfied
by Height (HAT in thousands of feet) multiplied by GS angle, and in any case at OM pos plus at Minimums. (One mum here is not always inough)
For example at airport with elev of 2000 feet, 9 NM from Threshold, if you are 5000 feet,
3*(5000-2000)/1000 !! You are on GS. Any mile less or more and at least you know where you are.
Beside there is no 100% guaranty you will get GS at all, so BE prepared with LLZ ONLY app minimums.
Have a nice day !

[xetroV]

Originally Posted by samolyot

Out of interest, for any non-Dutch speakers, The Dutch press are reporting a representative from TALPA blaming wake turbulence due to a 757 which landed earlier. The Dutch VNV is denying this, saying that a 2 min margin is normal

nu.nl/algemeen | 'Ander toestel mogelijk oorzaak crash'

Haven't seen this report mentioned in the English speaking press

Here's the news in English:

Turkish pilots association says "wake turbulence" likely crash cause

Seems TALPA wants to play the blame-game instead of waiting for the investigation to proceed. Very unprofessional.

[Atreyu]

A380-800 Driver, this one had been done to death ad nausem, no fire doesn't mean no fuel, the fact the wings stayed intact means there was no fire.

Samoloyt, From what I understand the B757 is classed as a Heavy Aircraft regarding it's wake turbulence, so I imagine a B737-800 would need a 3min seperation, although don't quote me on that one! The wind was 30 degrees off the centreline of 18R both at altitude and on the ground, and therefore should 'blow' the wake to their left as they made their approach, although such a light wind being only 30deg off may not move the wake sufficiently away from their intended flightpath.

Atreyu

[eltonioni]

This idea of wake turbulance keeps getting mentioned, but I'm struggling to see how it can be a problem if on the ILS for the same runway as the preceeding aircraft.

Please tell me I'm not being incredibly stupid. *




* Somebody competent please. Sadly I feel that this thread has reached the point where we need to qualify ourselves... so I'm an IMCr rated PPL who is worried that he's missing something obvious and I don't fancy flying an ILS upside down.

[Atreyu]

Belgique, Very good post, would you agree it was the energy imparted into the rest of the fuselage when the tail impacted that caused the most injuries/fatalities?

Atreyu

[scrivenger]

Has it been determined where the crew were positioned, and if so who was sat where and who was doing what. An odd/non standard pilot configuration may not have helped during any emergency initiation procedure. Is it possible that it was the initiation of a non standard training procedure that set the train of events in motion.

[Lost in Saigon]

Originally Posted by Dysag

Do you have it from a reliable source that the "learner" or "apprentice" was in the jumpseat? I've been wondering about that.

Good point. I just assumed he was in the jumpseat observing.

Most airlines I have worked for do line training with only a Training Captain and the trainee.

At Vietnam Airlines I was twice asked to ride jumpseat as "Safety Pilot" and be available for take off and landing in case the "trainee" was totally incapable. The rest of the flight was spent relaxing in "J".

This is the only airline I know to do this. Are there others?

[Atreyu]

Eltonioni, wake turbulence is a well documented problem, if the wind is flat calm the vorticies will not dissipate easily, and flying through them isn't something to be taken lightly esp. in a light aircraft. The higher the wind and the more of a cross wind component it has, the faster the wake vorticies will dissipate; literally being 'blown' to the side.

This is where seperation of aircraft comes into play, it all depends on the weight class of your aircraft, and the weight/wake class of the aircraft in front of you.

If your flying your 172 on an ILS, to be on the safe side I'd give at least 5 to 6 mins of seperation between you and even a light jet such as Fokker 100, BAe146 or a CRJ. Maybe your AFM will give guidence on wake turbulence (as in flying behind a wake generating aircraft)

Atreyu

[no sponsor]

Wake turbulence could lead to a loss of control, and a departure from the intended flight path. However, if the transponder plots are accurate, there appears to be a steady loss of speed over the course of a substantial period of time. I say substantial because response for any speed deviation from your Vref + 5 (or whatever it is for THY) should be immediate, particularly if you are slow. As someone else posted, it appears to have been on the G/S for at least some of the approach.

Of course it will come out in the investigation, but I am keen to see exactly what mode of automatics were in use at the time.

[Wizofoz]

Good point. I just assumed he was in the jumpseat observing.

Most airlines I have worked for do line training with only a Training Captain and the trainee.

Every airline I've worked for put's a saftey FO in the JS for the first several sectors line training of a new hire pilot.

[eltonioni]

Atreyu I understand all that, but the vortices are still heading down even in light wind. So assuming proper ATC separation why would this be a problem, especially for a 737?


I'm not being rude but bearing in mind how silly most of this thread is and just to clarify, I'm assuming that you are a qualified and current pilot who might just know what he/she is talking about?

[Atreyu]

Eltonioni, Yes I am a current fATPL on the RJ series (tarted up 146)

I do seem to remember they descend at a given rate but bearing in mind they won't be moving forward at anywhere near the same speed they were when they left the wing, and with wind and perhaps thermal activity, you could find a situation where you catch the vorticies up.

You are correct, with proper seperation wake turbulence shouldn't be an issue, but the question that the Turkish Pilots Union (TALPA) is raising is whether the proper seperation was maintained? But the responsibility ultimately falls onto YOU the pilot to manage wake seperation, the question could be did the crew take into account the heavy wake vorticies catagory of the preceding B757?

(of course assuming there even WAS a B757 preceding...or that wake seperation was inadequate)

[Rainboe]

888888888888888888888

[Lon More]

Dutch news reported that a Preliminary Report should be made next week

[PJ2]

Originally Posted by protectthehornet

I'm not sure what the guy was saying about DC8 throttles not moving...unless he meant that they had to be moved by hand.

I didn't think I had to specify but yes, that's what I meant. The point I was making was, in the concurrent discussion regarding automation levels, non-moving thrust levers/throttles are not new - those who have been around a while are already familiar with manual throttles and use thereof. The A320/340 series aircraft are the same when on manual thrust levers but the automation is, like any aircraft system when used with awareness and knowledge, a significant safety advancement. Flying the 320 in fully manual flight (no flight directors, no autopilot, no autothrust) is no different than flying any other transport category aircraft in manual flight. It takes a pilot, not a "flight deck manager" to do it safely...

DC-ATE;

Thank you for your response, much appreciated. Permit me a bit of latitude:

First, I want you to know that I find your posts very engaging and of great interest. I believe we're about twenty years apart if I recall a comment you made earlier perhaps on another thread, thus about half my career was spent flying "steam" on the DC9, DC8 and 727, and half was spent flying "partial automation" (767, L1011) and "full-automation" (relatively speaking) on the Airbus 319/320/330/340-300/500 series so I have a foot in each camp so I both appreciate and understand your approach and comments. Disagreement is, at least for me, a starting point, never a point of parting ways.

When I first began flying fully-automated aircraft I was extremely skeptical and was not silent about the kind of training and understanding being handed to new candidates on these aircraft nor was I the least bit impressed the arrogance of Airbus which summarily dismissed early commentary from experienced professionals on many potential automation human factors errors lying dormant in their design.

The airplane itself requires a minimum of six months steady flying to achieve a bare understanding and a year to feel comfortable. In my view and experience, one can "strap the airplane on" after about 3 to 5 years and play it like a concert grand but for many such levels of automation do not come naturally, either philosophically or operationally and so takes steady work.

Having flown the Airbus types for fifteen years I am wholeheartedly convinced that the approach taken and the design itself is extremely well considered and executed. No design is without it's shortcomings and resident detractors but the design must be critiqued from a basis of knowledge and experience - I think that is only fair; otherwise, what may appear to be nonsensical and "oviously faulty", is in fact a superb design when trained for and operated as intended.

My reference to the DC8 throttles as "non-moving" was an attempt to engage this larger dialogue - there were no autothrottles on the '8, and of course, they're moved by hand- it was never an issue then or now, the point being, neither are the non-moving thrust levers on the 320 series "an issue".

Your point regarding the mis-reading of the altimeter is absolutely spot on - it's a pilot thing certainly and I am certain you had no trouble reading the gauges but I would add, (and it's a small point in the overall discussion), when the design changed to the drum altimeter and all of a sudden CFIT accidents reduced.

That coupled with having their heads inside and low pay and all the other things wrong these days, just leads to unfortunate results

If I may be permitted one more tangential point:
Heads down and low pay are more than plain facts about this business and this profession after de-regulation - they are metaphors for a much larger and more serious problem now in its "post-seedling" stage showing signs of ripening.

There are, in the view of many including "Sully", gathering forces for a perfect storm where an increase in fatal accidents may obtain. Today it is marketing experts and accountants who make it into the senior executive. Airline executives in many cases are not only not knowledgeable about aviation and operations these days but cannot carry on an in-depth dialogue on how safety is done or what it takes to accomplish it.

That is not just my impression - I have heard it in dialogue with people (pilots in flight safety) at Boeing who would know. The comprehending support so crucial to those programs which produce "nothing", diminishes in favor of "cost control", a very short term project. It is as though those governing and directing airlines have forgotten that they are in the business of aviation and have forgotten where the present laudable safety levels have come from. The testimony before Congress of Captain Sullenberger emphasizes this point very poignantly.

This may be tangential but, as this and other threads have touched on these larger matters as we collectively puzzle why another fatal accident has occured, the point is only barely tangential. (So the springloaded on this thread don't leap to connecting this broad comment with "specific causal factors" in yet another tragic accident, I assure you none of us know enough yet).

Originally Posted by DC-ATE

And while this accident doesn't invole a FBW aircraft, I don't think I ever said that they were "difficult or obscure" to fly. I'm sure they (FBW) fly just fine. It's when things are not normal that correcting the issue seems to become a problem.

Okay, I accept that, thanks, DC-ATE. I gathered the impression that you were stuck at cables, pulleys and bellcranks and thought the A320 concept and design was a poor alternative - that is certainly the impression I have of others' who criticize the airplane.

As I state, my bet is, those who criticize most heavily either don't fly at all or haven't flown the 320 and so are emminently dismissable - even some (not all) comments from engineers; one simply has to have experience with the airplane before either lauding it or criticizing it.

So in your last comment, I understand precisely what you are saying and would agree with it because it is so obviously correct - if it were applicable. But the notion that there should be an emergency regime, "the so-called 'big red button' ", in which the flight/engine controls may be "in extremis", connected directly by cables to their respective services is folly and dismisses the vast and historical experience with hydraulic assisted controls, fuel control units and military experience with fbw systems, just to name a few.

The industry experience with the Airbus and Boeing fbw systems is clear - it is a successful approach which does not merit reconsiderations in terms of reverting to big-red-button thinking.

In my opinion, it just doesn't work that way nor is there the demonstrated need. In fact, it is rapidly becoming apparent that the Perignon accident shares a number of similarities to the Airbus A330 accident at Toulouse and likely has nothing to do with the design itself.

[BarbiesBoyfriend]

We were no. 3 when the THK was no. 1.

The wx was utterly benign. There was no ice.

Only thing we noticed was that it seemed ATC had packed too tight. Of course now we know the THK had slowed, so maybe that caused the no.2 to slow also, thus reducing the gap between us and the no.2.

After the no.2 was sent around we thought the problem was over as we'd have a decent gap now, but we heard ATC ask the no.2 if he'd seen anything on the ground which was a bit alarming. Shortly after we got sent round too.

Just posting events as we saw them. No idea of the cause. Never saw the Turkish.

[Atreyu]

Rainboe, agreed entirely, the aircraft landed wings level in a nose high attitude, so wake turbulence isn't likely at all. I was answering Eltonionis questions regarding wake turbulence.

As I said previously, being number 3 to TK1951 on the ILS, I can say the weather can't have been the prime factor, it was murky but def. CAT1, even non precision weather IMHO. Icing wasn't present, and conditions weren't conducive for windshear.

Atreyu

[ASRAAM]

LIS

Yes, its commonly referred to as the FlCh trap and we cover it during initial sim training and every couple of years. Hopefully other operators do to.