Turkish airliner crashes at Schiphol

[737AvEng]

I've started a thread in the Tech Log forum in regards to the technical aspects of the 737NG radio altimeter/autothrottle/autopilot interface. I noted my observations while performing some tests.

http://www.pprune.org/tech-log/36648...ml#post4797696

[bubbers44]

Thanks,737AvEng, for doing those tests. A while back I posted what if the #1 RA had failed to -7 ft before the approach was started but only went to retard on glide slope intercept. If you get another chance to try different failures would you try failing the RA to -7 ft before starting the approach? It might be something worth crosschecking before starting an approach or changing the software so the autoland will not arm if this fault happens again.
Corrosion around the antenna has been mentioned as a probable cause for this to happen so it probably will happen again.

[atceng]

error may not be the same as failure

With trepidation in this apparently exalted company I would point out that there is a critical difference to the softwares' processing of data coming from a source which has self tested or otherwise signalled to the software 'FAILURE', compared to the processing of a parameter which is erroneous.
In the absence of a comparitive function and/or detection of values outwith a 'normal' range the eromeous RA values would be processed in the same way as 'true' data. e.g. negative altitude value,as the software would have no way of detecting that the data was incorrect.
The very valuable tests you are conducting must take cognisance of this,and contributors should be very careful only to use 'failure' when the instrument has outputted a failure signal or the software has otherwise detected invalid data,flagged the source as 'failure' and processed/ignored the data accordingly.
The softwares' reaction to 'failure' c/f 'erroneous'(undetected) will be poles apart.

Apologies for being so pedantic,but unfortunately there is nothing so pedantic as control software,miss out e.g. a closing bracket and it bites your @rse). Where DID I put that opening bracket?

[Baron737]

I don't recall all the indicator or system faults I have encountered in the last 40 years, as I am pretty sure the majority of pilots in this forum, and in some situations hit the panic buttons: the one on the yoke and the one at the side of the throttles.

I agree totally. And I donīt get the point of all that system discussions. A failed RA indication is nothing serious. I guess it happens more than once a day.

Loss of control is the number one killer since CFIT has been stopped by maps and EGPWS. And no envelope protection in any kind can stop this. There are already airlines operating, where it is mandatory that the FD is kept on at all times !! (itīs the best way of preventing pilots to watch the basic indications)
Just ask yourself after a FD approach:
Which pitch did i fly ? Which vertical speed did I fly ? Automation will NOT help
in reducing loss of control killings.

[captplaystation]

Baron737 you are so right. . . . . but, in everything in life we must find the "happy medium".
I have worked for companies who
A - encouraged, indeed by the standard they "expected" in SĄm checks ,in fact they "insisted", that you were really hot (i.e. spent a bit of time ) hand flying departures & approaches in raw data (FD off )
All well & good until , yet again, Mr Le CoPilot is yet again about to severely bust the altitude restriction on a departure from a busy Central European TMA (There is a clue there ) keeping himself up to the standard required to pass his sim check OR
B - Begorah ( Another clue ) where the pilots almost wanted to declare an emergency if you didn't engage the A/P on departure @ 400' and disengage it @ 500' resulting in total inability of aforesaid copilots to fly a Cessna 150esque visual approach (and even more worryingly self same bod 3 yrs later unable to do same when about to become a Captain )
So, like most things in life, there is a happy medium.
Yes, it is important to be able to fly the aircraft safely ( and indeed fairly accurately please ) with everything turned off . Please practice this sometimes, but please do so when you do not compromise good operating practices by effectively rendering your co-crew member single crew (i.e. not during departure in a busy TMA)
It is also very important in the busy airspace we inhabit, to be able to use (all ) the wonderful featuress available on the MCP (and the imagination to select the mode to be used wisely - VS is your VERY best friend ) to reduce your workload , and therefore stay a little ahead of your aircraft.
The choice of the two should vary infinitely depending on airport/crew/experience/perceived alertness on the day, and is the ultimate expression of exercising wisely your "command authority".
On a more general note, I am at a loss & totally aghast, to see an experienced crew from a "legacy carrier" screw up ( on the face of it ) so badly.
However, in several years spent commuting, I often (due to being sociable, but yes , also due to "curiosity" and indeed a desire to learn) passed many a flight occupying the Jump Seat.
I have never ( I am happy to say ) had to intervene, but there have been many occasions that I silently shook my head whilst patiently ( ? ) awaiting the "paid employees" to do their job.
It is a truth in life that it is always easier from the 3rd seat, sitting behind & watching,for that, I am in total agreement, and therefore even more perplexed that in AMS , even that didn't save the day. Incredible, truly and sadly , incredible.

[Baron737]

@captplaystation: The choice of the two should vary infinitely depending on airport/crew/experience/perceived alertness on the day

Absolutely right

And I have no problem, if someone decides to fly only one ītraining approachī (only IMC counts) out of 10 or whatsoever.
But if someone NEVER switches off the automatic in a 5 days tour, and says the sim missions are enough training for him, something is dangerously going wrong. If a colleague doesnīt find the disconnect buttons although he is above glide with high speed and the A/T is just adding full power something went really wrong the last years. (If you NEVER switch this FD off when you have no pressure, why should you do it when in panic ?) Our confidential safety recordings show those incidents in dramatically rising numbers. Until today we were lucky, but you canīt run an airline by luck.

[BAe146s make me cry]

Tee Emm

As I'm an Avionics Technician, I found your last post shocking.
That said, I don't disbelieve you either. There are numerous
slips of standards for EASA Licenced Engineers too.

I can appreciate there will be a few F/O's out there more inclined
to engage A/Ps & A/Ts quicker in various configurations. But, I wasn't aware that big outfits actually encourage or 'train to monitor automatic flight only'... That really is wrong.

I'm disappointed actual flying proficiency standards under EASA have dropped too. But as Graybeard has mentioned, more losses seem imminent unfortunately.

BAe

[Artie Fufkin]

Nice to see the old "whats the difference between FOs and ducks?" still routinely rears its ugly head.

The PF was not properly monitoring the automatics during the approach, and the plane crashed when the captain took control of the stall recovery without putting his hands on the thrust levers. FOs (and captains!) practicing raw data, manual flight is a good thing, but the lack of was not the cause in this accident.

Still, at least ducks can fly!

[Aeroengineer1]

standards

BAe 146s make me cry

There are numerous slips of standards for EASA Licenced Engineers too.

Zillions of them. Even, for ATPL modules. I wonder who prepares those standards.. Guess they are Gods. Don't want to talk about so called ATPL theory textbooks.....

[flyburg]

Wow, this thread has now developed into a automatics versus handflying discussion. I wonder though if that was really the case. Both pilots occupying the pilot seats were ex AF. I doubt wether they weren’t capable of manual flying. I see a lot of human factors in this accident.

Presumably, the FO was being trained as a new FO on the A/C, he was also (presumably new on the A/C as there was a second FO (in my airline we do that in the first week on line training)

He came in established on the localizer and intercepted the G/S, more than likely the pl went to idle as he was going down and lowering the gear and lowering the flaps, basically slowing down. Shortly thereafter the faulty RA caused the AT to engage retard mode. The exact sequence doesn’t matter. The pl did what one would have expected them to do, the only thing wrong at this point was that the FMA annunciation read RETARD instead of MCP speed. The FO might, I stress might, have seen this but being new to the A/C not have realized even that that was not the correct annunciation. Once again the pl’s did what one would expect at this point. The captain may not have noticed because he was busy lowering the gear and selecting flaps 15(probably watching the speed and altitude and maybe even the GS annunciation, but not the retard annunciation) .

All was normal for the next approx 70 seconds. The A/C did exactly as it was supposed to do,slowing down. They next selected flaps 15 and rotated the MCP speed selector to FAS. This is where the second clue that something was not right should have become apparent, the AT didn’t move forward to maintain FAS. Having spoken to two college’s that tried it in the sim, it took 25 seconds to decelerate from FAS to stickshaker speed. So what occupied the pilots that they didn’t notice the speed dropping below FAS? Well, for one, they were reading the landing C/L. It takes about 4 seconds and boeing says that both pilots have to look at the selections. However it was a training flight, maybe the FO forgot to arm the speed brakes, maybe the captain forgot the select the engine start switches to CONT. In any case, for 25 long seconds they did not notice that the speed went from FAS to stickshaker.( bad airmenship for sure, but still I wonder what kept the occupied).

Finally, the stick shaker went off(somewhere around 800 feet) completely unexpected. The FO, out of primal training pushed the pl’s full forward( and mistakenly didn’t push the AT disconnect button, btw, I think boeing may face a law suit there because the FCOM procedure for a stall recovery does not explicitely says to disconnect the AT, common sense notwithstanding)) and probably pushed forward on the yoke. At this moment the captain took over( I heard this from a reliable source).

So here you are, the captain took over at a critical point, probably using both hands to push the yoke forward, more than likely an autopilot disconnect wail going off, possibly a “glide slope”, “sink rate” or “terrain” warning going off and the captain not noticing that the PL’s were going back to idle.
The rest is history!

So was this an automation v. hand flying deal. Who knows. The FO could have been the best stick around. Maybe it was not his hand flying skills but his understanding of the automatics that did him in. Showing proficiency in automatics is also required in getting a type!! Maybe because he was such a good stick but not knowing the modes of the automatics was the problem.

So, In hindsight, I don’t think there is anything wrong with the airplane design, It did wat it was supposed to. There may not have been anything wrong with the manual flying skills of the flight crew. It may have been a training flight were all the holes in the swiss cheese lined up.

The FMA unnuciation shortly after GS capture, RETARD instead of MCP, I could have missed that, The PLīs not going forward at FAS, I wouldnīt have missed that(hey, Iīm a nervous flyer),missing the AT disconnect button in a completely unexpected stall condition at 800 feet, I wonder!!! And then missing the PL going back, fighting a stall with a myriad of warnings going off, I wonder how many guys would have caught that.

If you ask how many guys would shut down the wrong engine? a very unlikely situation, and still that happened in the UK. So I can completely see how a crew could miss disconneting the AT during a high stress event!!

[TowerDog]

So I can completely see how a crew could miss disconneting the AT during a high stress event!!

No high stress event going on..Normal approach, decent weather, good airplane, an extra pair of eyes and ears in the cockpit....

If ya forget to fly the plane things could turn into turd real fast..Then if ya forget to disconnect AP and AT when turd hits fan, it could get real nasty up to an including crash.

No big surprise going on here, just very basic flying...Or lack of.

[stillalbatross]

Double RA fault on a A330 a while back and the autothrust locked at the thrust setting the engines were at the time. From memory it was MAS arriving into Melbourne. What kind of a system would allow RA failure to retard the engines to idle, that sounds unwise to me. Though I agree even the newest 737 is 3 or 4 decades older technology than the Airbus.

Pity it wasn't a 320, alpha floor would have saved lives.

[BOAC]

Originally Posted by flyburg

I think boeing may face a law suit there because the FCOM procedure for a stall recovery does not explicitely says to disconnect the AT, common sense notwithstanding

- well, I don't! The Boeing procedure calls for the setting of max thrust by PF and the verification of this being achieved by PNF, and furthermore for PNF to announce anything missed from the procedure. It is really quite simple.

[chrisN]

Flyburg, should your account also include things others posted earlier – descending out of cloud, trying to get a visual fix on the runway, but the AP was getting the nose high to keep on GS with decreasing speed, so they might have been looking too high up and taken longer to acquire it?

Chris N. (Trying to get a complete possible scenario to illustrate workload issues, for a safety talk – although the real story may or may not confirm this when the transcript of the cockpit voice recorder emerges and the investigation is complete.)

[LorryDriver]

Turkish press update

Turkish Daily - Domestic Press Report from March 20 regarding estimated lawsuit

Boeing faulted in THY disaster in Netherlands

[Smilin_Ed]

Ambulance Chasers

The two U.S. attorneys, Gerald C. Sterns and Martin T. Reilley, and U.S. international aviation consultancy firm owner Terrence Ford, held a press conference yesterday in Ankara about the responsibility of the American Boeing company in the plane accident.

Otherwise known as ambulance chasers.

[Norman Stanley Fletcher]

Due to the emontionally-charged nature of this particular thread and the almost impossible task of having a rational discussion on civil aircraft design as embodied in Boeing and Airbus aircraft, I will perhaps steer clear of too much discussion on this subject for the moment. Suffice to say, that difficult questions have to be asked over any aircraft that could allow this to happen. As others will rightly point out, 99.9999% of 737 approaches occur without incident, but in our line of work we should consider the 0.00001% case. A combination of factors occurred here (very well laid out by flyburg a short time ago), and as a result many people died who did not need to. No one is going to come out of this well - Turkish Airlines, Boeing and the individual pilots all had key parts in the jigsaw of factors that led to this accident. I trust that even the most hardened Boeing supporters will be willing to say that this is not an acceptable fault to have lurking in the background. As an Airbus operator, I would put my hand up and say that there are certain features of Airbuses which are potential glitches to inexperienced crews on type. Nonetheless this particular accident would have been almost impossible on an Airbus, and I hope that future Boeings will introduce a facility, as has been present in Airbuses for over 20 years, that prevents the crew from stalling a serviceable aircraft (or indeed one suffering minor snags).

You will never fully eliminate pilot error, however alarming and fundamental those errors may be. Nor will you totally eradicate company cultures that permit dangerous situations to develop without them being instantly challenged. Both of these 'human factors' considerations are clearly something we should aspire to change, but that is a very long term aim. Therefore the final protection has to be the aircraft itself. In this day and age the technology exists, and is in daily operation around the world, to provide significant protections against the first 2 lines of defence failing. I hope that in the future the world's biggest airliner manufacturers will take full advantage of the readily-available and proven technology to provide maximum protection to the travelling public.

[captplaystation]

I'm all for that Norm, but you have to admit, it is a little bit when American lawyer and all round aviation specialist Gerald C Sterns assertion that " the Turkish pilots had no fault in the accident" will probably receive widespread acceptance where it has been published, and for all the wrong reasons.

[EMIT]

To stall or not to stall

Qoute from NormanStanleyFletcher

"that prevents the crew from stalling a serviceable aircraft"

The A-320 in Bangalore, many moons ago, was not stalled, but it fared no better than the THY B-737. In fact, if I recall correctly, every soul on board that non-stalled airliner perished as the autopilot neatly descended it into the ground, thanks to a clueless crew, clueless to perfectly annunciated FMGS modes.

Please note that this post is not Airbus versus Boeing, I am experienced on both and know well that both have pro's and con's. Point is that in the end, it is the crew that must save the ship.

And about lawyers - you know how you can tell the difference between the carcasses of a rattlesnake and a lawyer on a desert road?
The rattlesnake corpse has brake/skid marks in front of it.

[bubbers44]

The lawyers are going after the deep pockets so Boeing is their target for blame. The pilots probably don't have enough in their estates to be worth a lawsuit.