well I'm not sure if I get deleted but I try it nonetheless...

Nick, a transponder signal is never accurate as to read out a real speed of an aircraft. If you had the chance to watch some modern TCAS/ACAS systems, you can easily see how inaccurate they are. Transponders are not there to determine the speed of an aircraft but it's position (with a relative wide error).

This is especially noteworthy in case of an aircraft that decelerates or even stops. If your exampel aircraft would stop, and you would measure the speed 10 seconds before crash landing, which speed would it be? Most probably the average of the last 10 seconds.

Only the readout of the flight data recorder will give us reliable evidence on how the aircraft crash landed.

FSLF, teh picture shows a landing gear, but not the evidence if it was extended...

Ah, and DC-ATE, my favorite enemy, is also here! FBW aircraft are not stallable. And stick pusher close to ground is very very deadly. An Airbus can be flown at the lowest allowed speed with full controls without risking a stall, while on conventional aircraft you always have to build in a safety margin. Remember Habsheim.

Dani

Roof Panel
 

AP

If it helps, I saw some TV coverage showing rescue crew hacking at the roof above the cockpit while the commentator stated that there were bodies there to be recovered.
Ergo, I guess any panel was still in place.

OB96

TT, I agree with your conclusions. We saw the same file for the Nimrod with the same conclusion. Of course when a ditching actually occurred everyone survived.

Afraid I am only a GA pilot so forgive the questions.
I would have assumed that when a heavy aircraft is in landing configuration at a 'final' stage then there would have been a 'gear not down' warning.
I understand that there seems to have been no communication of a problem to ATC, which seems to indicate that everything happened very quickly and very late indicating that the crew were unaware of the emerging situation. However, if you have a 'power out' on a heavy aircraft will this kill the comms?

Belgique,

In my previous post (page 13 or something) I mention a similar thing, namely the backtrim during an dual-channel ILS, which can take people by surprise when forced to Go-around manually. This together with a very low speed regime is indeed a trap one would not want to set a foot in.

You do indeed get a gear not down warning, as notified by your GPWS.

More details can be seen at Ground proximity warning system - Wikipedia, the free encyclopedia

The voice is very loud in the cockpit, so no chance of missing it. You can of course turn it off, as required by some check-lists in non-normal situations.

I would just like to add that after listening to the ATC files at the time of the crash the Dutch controllers seem a very professional group, kudos to them in what must be very demanding circumstances. :D

Belgique & dani, 737 is not fitted with stick pusher (no t-tail no deep-stall) merely stick shaker x2.
Belgique ref your remarks about lack of attention to speed due over reliance/confidence in Autothrottle. I have never worked in a company (and I have flown the 737 in quite a few) where you wouldn't be severely barked at on any sim or line check if you didn't follow through with your mitts even on a A/T controlled approach. I doubt Turkish are any different in this respect. From 1000ft down what else is there to look at except the glideslope localiser & speed ( I have never got the hang of doing crosswords in the last 3 miles ;) ) I think the syndrome you refer to is much more an Airbus thing, as of course there is ( very stupidly I feel ) no thrust lever movement when using autothrust to give you a much neede tactile clue of what is going on without recourse to eyes & ears.

From the german Spiegel:
Flugzeugabsturz in Schiphol: Piloten von Instrumententafel erschlagen - SPIEGEL ONLINE - Nachrichten - Panorama

...
The pilots in the cockpit were killed by an instrument panel, it were said.

The third pilot on board the machine, the 29 year old Olgay Özgür, received obviously a training for the type Boeing 737-800, even if he had already had a pilot license since 2004, said a speaker of the airline on Thursday in Istanbul.
...

POB Vs SOB
 

Apologies for being irrelevant to this page's discussion but to clarify:

POB - Passengers on Board
SOB - Souls On Board

It is a clear and necessary distinction for Operations.

What happened then?
 

Guys,
from the metar/Taf there where no evidence of gusty winds/strong winds so we can exclude windshear.Probably they where in IMC Wx conditions before they crash but an EGPWS call "Pull up terrain" should have save them from crashing so we can exclude that as well. Bird strike with double flame out on final is so rare and anyway they should be reports of birds activity in the ariport area and they are not.
May be they had a fuel leak but the FMC should have alert them about insufficilent fuel and for sure they would have declare an emergency in Schipol area to be first in Approach. So what do you think guys?

The Dutch controllers are outstanding. The amount of traffic, parallel approaches, and general high levels of activity really do require them to be at the top of their game. Certain countries make you a little nervous, to say the least, but not the Dutch. Very professional bunch.

skyclear1984, in a much earlier post it was stated that there was a bird alert in force, and another poster (if I remember correctly) stated that landing there on the same day there was a lot of bird activity.
As you are from Italy I am surprised you think bird-strike double flame out is SO rare. Never mind the Hudson (albeit on departure), have you already forgotten Ciampino ? I still wouldn't be surprised if this was number 3.

Are you sure about that? For years I've been passing POB figures as meaning persons on board i.e. the same as we previously called souls on board. It's been that way in my last two airlines which doesn't necessarily make it correct but I've never heard of passing a POB figure that doesn't include the crew.

EDIT: I've just checked the UK CAA definition of POB and it is "(Total) Persons on Board". I know this isn't that relevant to what caused this crash but it's come up several times in this thread so hopefully this answers the question.

B 737 ovhd pnl
 

For those who wonder how heavy it is belive me when I say that they are HEAVY. Difficult to say how much exatly but a good guess could be atleast 30 kg (65 lbs)
Its hinged in one end like on many other aircraft types.
If it would just fall down when sitting on gate it could probably easily know you out so imagine what it could do with some velocity


Wings 1011

Which of course is not to say that the impact force at the nose, as it hit the ground, was in the region of 2g.

More than anything I wish people would stop making posts in relation to possible human factors that this, that or the other is "inconceivable".

There are many, many "inconceivable" accidents filling the history books, and each one generally teaches us something new, or reinforces the importance of something else. How can any of us say with any degree of certainty at this point, that we are not all about to learn something brand new as a result of this incident?

I'm not suggesting in any way what the cause/causes of this accident may be, but stop fooling yourselves that humans are infallible and that training, procedures and automation are going to save your ass.

Dani

I don't claim that the transponder transmissions tell us anything definitive, but I would expect that the aircraft's GPS receiver(s) would have an update rate of 10Hz for both position and speed, so a transponder transmission will contain the latest and very recent data.

I don't know how aviation GPS receivers calculate velocity, but I would expect it to be based on doppler frequency from the SV signals as extracted by the correlators. Pretty accurate in terms of ground speed, usually to 0.1 x displayed velocity units for a consumer GPS.

If anyone here knows the B738 avionics well enough to comment on whether I'm being realistic that would be useful.

The guy with the receiver near EHAM tracked TC-JGE over a period of 37 minutes (may not have been continuously, I don't know), and received 1042 Mode-S messages from this aircraft during that period. On average that's one message every 2.1 seconds.

With my own Mode-S receiver, if I have a single B738 in range I see between 3 and 7 messages received per second, so the update rates are pretty high for an ADS-B equipped aircraft, in a dense environment though a fair percentage of these will overlap in time with other aircraft so there is a larger chance of missing a given message.

When the FDR data becomes known we can see whether this report is anywhere near the truth.

I hope those boffins did their calculations based on dynamic similarity and not just scale, else the results would have been way out.... it's not an easy science, energy absorption and instantaneous accelerations, very dependent upon hard to model specifics. Today I imagine, it would all be done using finite element analysis...

Could the thing that pierced just behind the roof of the cockpit be the armoured door ?

GPWS considers the A/C landing with gears down, and this inhibits the mode 2(excessive terrain closure rate/PULL UP) operation.
Anyway, the system only alerts if the terrain closure rate exceeds a certain value.

No EGPWS Alert on a coupled ILS Approach
 

.
The theory in post 348 was that the a/c stalled whilst on a coupled ILS and because the "non auto-throttled" autopilot was maintaining the ILS glideslope at the expense of speed (i.e. kinetic to potential energy) - and not dropping below it and triggering the EGPWS alert.
.
.

That's not quite true. I'm very familiar with that area and to be honest, if the pilots had any decision room left at that stage, they made the perfect decision as to where to land the plane.

About one kilometer earlier and they would have crashed on a dual-track railway line or the N200. The N200 is a dual-carriage motorway which sits in a depression at that point, with elevated entries and exits leading to a complicated 3-level junction ("Rottepolderplein") about 500 meters right of the flightpath. Immediately after the N200 they would find a few industrial buildings and then the "Ringvaart", a 40-meter wide canal with straight edges.

To their right, about 500 meters, would be the 6-lane highway A9, running almost exactly parallel. Again, the A9 sits at an embankment about 5-8 meters above the surrounding terrain, and is very busy at all times during the day. At the other side of the highway you'll find an industrial area.

To their left they would have some 300 meter clearance to some farms, and a little more clearance to the town of Zwanenburg. But this area is cris-crossed with small ditches, 3 meters wide at most, and a few farm roads that are slightly elevated above terrain level. And the farm roads are lined with trees whose stumps are about 30 centimeters in diameter.

A kilometer later and they would have hit the A9, who makes a 30-degree turn at that point bringing it under the 18R approach path. From memory, the embankment here is again about 5-6 meters high, since this 30-degree turn in the highway coincides with the "Haarlem Zuid" exit which is a rather complicated exit with multiple viaducts.

I agree that tops of the trees that line the N200 and the Ringvaart are not really obstacles to worry about in this scenario. But these canals and embankments, and the stumps of the trees lining the farm roads are. And the field where they crashed was virtually the only place where you could hope to put an aircraft down without hitting any of those.

Edited: Fokker52 provided this link:
from: 52.377339,4.711719 - Google Maps

Unfortunately Google Earth doesn't show the relative elevations of the various roads.

I would just like to add that after listening to the ATC files at the time of the crash the Dutch controllers seem a very professional group, kudos to them in what must be very demanding circumstances.

Could some kind soul point me in the direction of these files ??

Thanks

If and when you become a pilot, it will become instinctively obvious that it's always better to make a "controlled" crash as opposed to an "uncontrolled" crash by stalling and diving out of the sky. :ooh:

Traces of debris
 

A rough look at the traces of debris behind the aircraft as well as the explanations of passengers reveal that the plane hit the ground with close-to-zero horizontal speed, which might have prevented a fire.

Might there be a possibility that the captain, once he was absolutely sure that he would crash, has decided to deliberately pull up excessively to create stall, reduced the airspeed and hit the ground without dragging on the ground so that there would be a minimum level of horizontal friction (Which, in turn, prevented rupture of fuel tanks) but resulted in a heavy (Heaviest actually) impact to occur at the nose? (Cockpit)

Such a heavy impact that although no visible damage is seen from the outside, all the stuff under the cockpit to be pushed down into the cockpit, killing all the pilots, instead of 120+ passengers to burn in fire?

Very recently I have talked to a professional pilot who knows the captain very well, and he said that such a probability is very, very high.

Any comments from pros?

Auto Throttle Disconnect
 

Is it possible for the auto throttle to disconnect while flying an auto coupled ILS? If so, is there no warning chime or other indication? I am not a 737 jockey.

I disagree.I would imagine this is exactly the time that he would chose to say something.

Speculation can be distasteful if it is based on ignorance and makes an unfair assumption about a crew's performance.Providing it remains objective and draws no conclusion about the crew's performance,speculation is actually a wonderful tool that "tin-kickers" begin every investigation with.They just do it in private.Start with the plausible,slowly fine-tune it to the probable until the evidence finally gives you the undeniable.
We have been a bit lazy in describing this as a stall.Technically,the aircraft didnt quite stall.It was about to stall when it hit the ground.The "turbulence" the survivors spoke of was the stall buffet.
Belgique's last post restored some respect to the notion that speculation has merit.In it,he points to the "insidious" nature of speed bleed-off if the pilots attention lapses during an approach with AT off.Call-outs by both pilots throughout the approach are designed to ensure that stable approach parameters are never compromised in this way.His post also describes the unfortunate mix of full back trim,low speed and full thrust that can ensue when the pilot finally realizes the error of his ways.His causation para talks of the dangers of automation complacency and explains neatly how such a situation can develop.Not once does he tie it to yesterday's crash.It is simply offered as a topic for discussion that may or may not be central to yesterday's tragedy.
None of us know what happened yesterday.How did they get behind the drag curve so badly?Was it mechanical?Bird strike?Wake vortices?Was the wrong gross weight entered in the FMC?Were they victims of automation complacency coupled with incorrrect stall recovery?Is stall recovery with ground contact imminent part of our 6 monthly check?If not,why not?People seem to have ruled out weather and fuel and I think this is just common-sense.Professional pilots dont normally fly about with no fuel without saying something and the reported weather was benign.
Provided we remain rational and objective,speculation need not be a bad thing.

Dani -
And a good day to you, Sir!

I will rush right out and buy one after reading that!

As to Habsheim. I do not put much faith in anything that comes out of that investigation for the following reasons:

Air France Flight 296 @ Mulhouse-Habsheim Airport -

The cause of the accident is disputed, as many irregularities were later revealed by the accident investigation.

Third-party investigations into the crash dispute the official findings.[2] Captain Asseline asserted the altimeter read 100 feet (30 m) despite video evidence that the plane was as low as 30 feet (10 m). He also reported that the engines didn't respond to his throttle input as he attempted to increase power. The month prior to the accident, Airbus posted two Operational Engineering Bulletins indicating anomalous behaviour noted in the A320 aircraft. These bulletins were received by Air France but not sent out to pilots until after the accident.

However, the recorders were taken by the civil aviation authorities and held for 10 days until they were finally confiscated. When the recorders were returned, they had been physically opened and the magnetic tape had been tampered with. It could not even be verified that they were the original recorders. The four seconds of recording immediately prior to the crash were missing. In view of this, a judicial report alleged that the aircraft's flight recorders could have been tampered with shortly after the crash.

ogel
I think they would just be concentrating on trying to maintain enough airspeed to keep flying (not stalling ,which even at 50ft would not be a good idea) whilst avoiding anything big and solid immediately in their flight path if the aircraft energy allowed them. Finally there is not so much difference between stalling speed and say a buffer of 15-20kts (to ensure control) in terms of the "landing roll", a bigger issue is the potential for an unchecked rapid pitch down of the nose if you do stall, which may have been the killer here for the guys in the front. Given the location of the horizontal tailplane after the accident, it is obvious that from the initial impact no pitch control remained of course.
Don't think no matter how cool headed the Capt he would be planning as you suggested, with or without power or sufficient airspeed I think he would merely be trying to make as soft as possible the off airport landing to try & save his own & everyone elses neck. Simple as that.

http://archive-server.liveatc.net/eh...2009-0900Z.mp3
http://archive-server.liveatc.net/eh...2009-0930Z.mp3

Edited: Posted links to wrong times

A/T Disconnect
 

You will hear a clicking sound as the A/T arm switch on the MCP goes from ARM to OFF and a red flashing A/T discrete light in front of both pilots.

The wreckage being all relatively 'together' and no
skid visible behind, would indicate that the aircraft
stalled and dropped like a stone - not the same
outcome as the BA triple seven at Heathrow -
unfortunately.

MM

Why Winglets departed
 

For those of you wondering why the winglets departed the aircraft take a look at this video

Really? I'd have thought the 737-800 would be like the 747-400, in which case an autothrottle disconnect will set off a warning beeper, and give an EICAS AUTOTHROTTLE caution message. The autothrottle switch on the MCP will just sit where it was...in ARM.

AT Disconnect
 

Thanks for the update on the 737 AT disconnect warning sequence. Sounds like it would be pretty hard to miss it but not impossible I guess. A red visual warning is fairly insistent. I must admit I have missed aural warnings when they are not repeated.

are we all thinking a pilot would get slow?
 

when you throw in the Buffalo, USA crash of the Q400 and all the talk about the crew letting the plane get slow and stall...and then people suggest the same thing might have happened in Amsterdam?

Something isn't making sense. Air speed on the approach is such a vital component of the instrument scan...

I do wonder if there is a computer glitch somewhere which might mislead the pilots with the display of airspeed?

And those of you who think the old ''steam powered '' gauges were bad...I'm wondering if we embraced these new efis types too quickly.

Didn't the 737 have problems with stab trim motor run-aways
years ago? Or am I getting confused (again!) with something else?
There were so many reported incidents that the aircraft had a "Nose
-up" attitude just prior to crashing, I wondered if that could be a cause?
It's a very sad event.

Autothrottle Retard
 

In 1986 I was involved with a situation at a small airline with 747-200 who had a rash of autothrottle retards at about 250 feet on approach. Turns out the radio altimeters were spiking down to 0 feet at that point, causing the A/T retard. Pilots reported it was subtle enough that it could have been overlooked long enough to cause grief.

GB

graybeard...you do have an interesting thought there.

now I know the Airbus 320 series doesn't have throttles that move automatically, but I thought the Boeings all did (my prehistoric 737 did).

We were required to have our hand on or about the throttles to feel them move during approach to make sure things were going correctly.