Pegasus Airlines Boeing 737-800 TC-CPF overrun runway at Trabzon. All pax okay [Archive]

pattern_is_full

14th Jan 2018, 01:50

AH has it now, with some imagery: Accident: Pegasus B738 at Trabzon on Jan 13th 2018, overran runway (http://avherald.com/h?article=4b39bd2e)

Looks like minimal tailwind, wet runway

LTCG 132200Z 33002KT 2000 -RA BR BKN006 BKN025 08/08 Q1020 BECMG 6000 RMK RWY29 30003KT=
LTCG 132150Z VRB01KT 4000 -RA BR BKN003 BKN025 08/08 Q1020 BECMG 6000 BKN008 BKN028=
COR LTCG 132120Z VRB01KT 4400 -RA BR BKN002 BKN025 08/08 Q1021 BECMG TL2200 BKN004 BKN025=
LTCG 132109Z VRB01KT 4000 -RA BR BKN002 BKN025 08/08 Q1021 BECMG TL2100 BKN004 BKN025 RMK RWY29 31002KT=
LTCG 132050Z 25001KT 2800 -RA BR BKN004 BKN025 08/07 Q1021 BECMG TL2100 3200=
LTCG 132020Z 24001KT 4000 -RA BR BKN003 BKN025 08/07 Q1021 NOSIG=
LTCG 132014Z 00000KT 4000 -RA BR BKN002 BKN025 08/07 Q1021 NOSIG RMK RWY29 VRB01KT=
LTCG 131950Z 00000KT 3700 -RA BR BKN003 BKN028 08/07 Q1021 BECMG 9999 NSW BKN011 BKN028=

turker339

14th Jan 2018, 06:01

Well the new photos taken in daylight show that it is a runway excursion and not overrun.

number0009

14th Jan 2018, 06:45

Good shots in this video.

https://www.youtube.com/watch?v=7bcSvO1_Ugg
......

Skeleton

14th Jan 2018, 06:51

Looks like a close call regardless of what happened. A little more energy and that could have been real nasty.

Avenger

14th Jan 2018, 07:44

Trabzon is not the easiest place, with a 3.3 degree glide, often TWC as you pass the valley on approach, short runway 2640M and non-standard runway markings. Normally in marginal conditions you would land F40 which is the 738 would be approx 130- 140 KTS depending on weight. The runway at TBN has a grooved section assist stopping. Having said all this technical stuff the real issue is the Pegasus culture: High Speed, always requesting shortcuts, requesting visuals in ridiculous scenarios and a proven track record of busting minima to land. The minima is either 600, 590, or 490 depending on GA %, normally operators use 600 which is 2.5% or 590 which is 3.5%. Unfortunately this looks like another case of busting minima, landing deep and the rest is history. As observed a little more energy and it could be world headlines.
This Turkish site has all the gritty pics, including the engine recovered from the sea ( or locals would have sold it in the bazar! )

http://www.airporthaber.com/pegasus-haberleri/pistten-cikan-pegasus-ucaginin-motoru-denize-firladi.html

fox niner

14th Jan 2018, 08:13

Lucky escape..!
Now, BEFORE the whole investigation process starts, we must make sure that the Turkish pilots are declared absolute heroes, no matter what.
I wonder what the cockpit gradient is, considering the slope gradient.

On-topic: 2640 meters is not a short runway for a 737. And he didnt use the last 200 meters of it. There must be something else to it.

Avenger

14th Jan 2018, 08:26

Kaza sonras?nda uçakta neler ya?and?? (http://www.airporthaber.com/havacilik-haberleri/kaza-sonrasinda-ucakta-neler-yasandi.html)

Heavy braking and skidded to the side according on passengers (if to be believed) Passenger interviews stating before landing the aircraft was veering , but they thought it normal for Trabzon, after landing aircraft slowed then suddenly increased speed and pax shouting its " not stopping" before it veered off. Aquaplaning/ rubber reversion lets see..but still doesn't explain laying less than minima
you don't need the last 200 metres if you are already dancing!

TBSC

14th Jan 2018, 08:30

Pano pictures, quite a close call.

Kaza yeri ve uçak havadan böyle görüntülendi (http://m.airporthaber.com/havacilik-haberleri/kaza-yeri-ve-ucak-havadan-boyle-goruntulendi.html)

reverserunlocked

14th Jan 2018, 08:34

Ouch. Lucky the hull remained intact on this one as it went off the side without much energy. If it had gone down into the water this would have been a lot worse than just an embarrassment.

sabenaboy

14th Jan 2018, 09:11

https://youtu.be/pCu-rd1nhO8

DaveReidUK

14th Jan 2018, 09:18

Speed from 1700ft downto 50 ft at 143-144 kts and HDG 111-122 deg, then 0ft 140kts as last data point.

The ADS-B altitudes look like they may not be corrected for QNH (1021 hPa), which would make them read about 200' lower than actual.

If that's the case, it's by no means certain that the aircraft had touched down by that final data point (about 1950' after the threshold).

guadaMB

14th Jan 2018, 09:26

Looking into post #10 pics, picture nº 5 shows the trace on the runway and on soft ground.
And appears to be a sudden change, but it also maybe an indication of high speed and a strong brake action in a sharp moment.
This is a guess: if PIC realized they were overspeeding and with 200/250 metres left, decided to do something vigourous and the AC didn't react in a straight direction.
Being Trebzon in Turkey, will be difficult to reach to an 100% sincere report...

sleeper

14th Jan 2018, 09:37

Kulverstukas

14th Jan 2018, 09:48

https://iasbh.tmgrup.com.tr/b40455/0/0/0/0/0/0?u=https://isbh.tmgrup.com.tr/sb/album/2018/01/14/trabzonda-faciadan-donuldu-gun-agarinca-ortaya-cikti-1515912424678.jpg

Avenger

14th Jan 2018, 09:53

Fortunately we have some native Turkish speakers here and they are saying that the PAX interviewed at more or less saying the same thing. Wobbly on finals, still in cloud and then slowed after landing followed by sudden speed up with PAX shouting.No suggestions of power increase just sliding around before tipping over the edge. Cabin crew and services did a good job.

physicus

14th Jan 2018, 10:03

RH engine looks to be a long distance away from where I’d picture it ending up if gravity alone carried it there. Residual thrust?

FullWings

14th Jan 2018, 11:32

...slowed after landing followed by sudden speed up...
After a period of sustained deceleration a significant reduction in the rate can feel like a speed up, for instance hitting a patch of standing water and aquaplaning...

Old King Coal

14th Jan 2018, 12:04

From the Jeppesen ILS plate for R11 at Trabzon (LTCG/TZX), the ILS CAT I Decision Heights (i.e. heights being referenced to 'above the ground', i.e. being referenced in the same manner as the reported cloud base):

2.5% go-around gradient = 496 ft decision 'height '.
3.5% go-around gradient = 436 ft decision 'height '.
4.5% go-around gradient = 386 ft decision 'height '.

For a B737 it's likely (read that as 'sensible') that one should be using the most limiting go-around gradient (i.e. 2.5%) the assumption being that you get an engine failure at the moment you press the TOGA button, that is unless your landing analysis data shows that you can get a better gradient than that, i.e. having suffered and engine failure at or in the go-around?!

From that weather (METAR reported above) you can read:

At time 20:20z broken cloud 300 ft height above the ground.
At time 20:50z broken cloud 400 ft height above the ground.

Some might of course retort that BKN (Broken cloud) is not a 'ceiling'. However, if the bit of sky that you're in is also the bit with the BKN cloud in it (and remembering that BKN = over half the sky) well go figure the view out of the window?!

So what's revealed by the above reported METAR is, whilst the visibility (which is the controlling parameter for commencing an approach) wasn't limiting, the cloud-base was sitting lower than the published ILS CAT I minima, coupled with a glide-slope that is steeper than normal (the ILS on R11 at TZX is set at 3.3º), as well as a slightly misty visibility and light rain... well let's just say that there are a number of gotcha's with that scenario !

DaveReidUK

14th Jan 2018, 12:10

really... oh come on, how's that possible ?! :ugh::suspect:

Humans' inability to accurately discern acceleration/deceleration forces is well documented. It's the basis on which all full-flight simulators work.

momo95

14th Jan 2018, 12:15

Some might of course retort that BKN (Broken cloud) is not a 'ceiling'. However, if the bit of sky that you're in is also the bit with the BKN cloud in it (and remembering that BKN = over half the sky) well go figure the view out of the window?!

I believe it's the case that it is defined as a ceiling when the cloud cover is 5-7 oktas (BKN) ... open to correction

Regarding the feeling of acceleration towards the end, apart from bodily sensations, could the power and noise of the reverse thrust have aided this illusion? The reverser doors are submerged in water in the images shown in all articles I've seen so can't even make out if they were open at the time of sliding

sabenaboy

14th Jan 2018, 12:19

OK. Here’s my GUESS.

The boeing was at very low speed when it went over the edge. Had it still had high speed, it would not have ended resting on the steep slope towards the sea, but IN the sea! The skid mark that can still be seen on the runway (picture below) already has a large angle from the runway centerline.
So here's what I THINK COULD have happened: The a/c was rolling at taxi speed toward the turn pad at the end of the runway, when suddenly there was a technical malfunction (NWS, left brake suddenly fully blocked…) causing the a/c to veer to the left. And just before it stopped it rolled over the edge.

I can’t wait for the official report to be released (hoping we ever get to see one :O )

https://iasbh.tmgrup.com.tr/b40455/0/0/0/0/0/0?u=https://isbh.tmgrup.com.tr/sb/album/2018/01/14/trabzonda-faciadan-donuldu-gun-agarinca-ortaya-cikti-1515912424678.jpg

FullWings

14th Jan 2018, 12:21

Looking closely at the photo, you can see a short skid mark from what was probably the left gear and it’s angled quite a bit off the runway direction. For an aircraft with ABS, that’s an interesting thing to see...

Edit: Crossed with sabenaboy. I agree with everything he says. It does make the possibility of some kind of malfunction more likely, as opposed to mishandling, so I think we should give the crew the benefit of the doubt for the time being.

edmundronald

14th Jan 2018, 12:30

Yeah, I'm just an SLF, but my intuition agrees with Sabenaboy - landing went ok, plane slowed on plan, pilots retracted buckets and decreased braking because they decided they were at taxi speed, which is where the passengers felt "acceleration", and then some steering malfunction or pilot error happened and then it went so fast and the airframe had so much residual energy that physics took over. I wouldn't blame this on bad landing execution, although it is quite possible some pilot error did occur on the ground.

A lot of people here -pilots- talk about the necessity of ensuring safe landing parameters for a potential go-around in the event of an engine issue, but no one ever speaks about safe taxi parameters to recover from a mechanical issue during taxi.

Obviously this runway is a really bad place for a runway excursion. Luckily Murphy seems to have been on lunch break.

The voice recorder in this one will be really interesting.

golfyankeesierra

14th Jan 2018, 12:31

So here's what I THINK COULD have happened: The a/c was rolling at taxi speed toward the turn pad at the end of the runway, when suddenly there was a technical malfunction (NWS, left brake suddenly fully blocked…) causing the a/c to veer to the left. And just before it stopped it rolled over the edge.
Happened before. Nose gear deflection on landing roll which initially can be compensated by rudder but not at low speed.
nosegear malfunction due to birdstrike (http://avherald.com/h?article=3d7d1ed6)

Doors to Automatic

14th Jan 2018, 12:45

I read a very interesting article in the internal BA pilot safety magazine last year alerting pilots to a phenomenon that I had never even thought of before. Quite often the aircraft has slowed to "reversers stowed" speed, say 60kts well before the end of the runway and then, because such as here, there is some way to the end, kept at a relaitvely high speed to expedite the landing. Suddenly the end of the runway comes up faster than expected and the PIC panics and hits the brakes hard. I am wondering if that is what happened here followed by some sort of lock-up or aquaplane.

Final 3 Greens

14th Jan 2018, 12:46

Just a speculative thought

- the aircraft apparently departed from taxi speed, to the left of the runway
- the right engine is in the sea, the left engine is still attached to the pylon

Any potential for some kind of power increase on the right being a contribuing factor?

It could also help to explain the perception of acceleration (though earlier posts have commented on other reasons for that).

PENKO

14th Jan 2018, 12:53

They we're going to make a 180 degree turn on the runway at some stage.

brakedwell

14th Jan 2018, 13:09

Something caused the aircraft to suddenly swing left 35/45 degrees. The port wheels skid mark show the aircraft was travelling in a straight line when the wheels locked up for a short distance then rotated again before crossing the runway edge, which is skid mark free. I suspect there might have been a problem with the nose-wheel steering. For the captain's sake I hope so.

silverstrata

14th Jan 2018, 13:09

Looking closely at the photo, you can see a short skid mark from what was probably the left gear and it’s angled quite a bit off the runway direction. For an aircraft with ABS, that’s an interesting thing to see....

Indeed. But if the brakes locked up, you would expect a double-black line parallel to the runway, and then making an excursion to one side. A short brake lock-up at 45 degs to the runway is odd for so many reasons.

Its position might suggest a controlled excursion to the right side of the runway, before the big excursion to the left. As if making they were making the 180 to backtrack at too high a speed. But the brake lock-up is still odd.

RVF750

14th Jan 2018, 13:11

B737NG Anti skid cuts out at very slow speeds.. I'll leave it at that. I would put my money on a perfectly servicable aircraft, long landing, heavy manual braking and when they reach 18kts, the anti-skid cuts out, he locks the left wheels and off he goes.

Off to the bookies now.

FlightDetent

14th Jan 2018, 13:25

4.5% go-around gradient = 386 ft decision height.
For a B737 it's ...

The OEI G/A performance is markedly better than 5% grad, not an issue. Ergo BKN 400 ft not an issue.

Not that it would had antything to do with an almost 20° veer-off 2400 m down the runway anyway.

sabenaboy

14th Jan 2018, 13:26

and when they reach 18kts, the anti-skid cuts out, he locks the left wheels and off he goes.

If he were at 18 kts at that point of the rwy, that would be a very normal speed. There would have been no need for heavy braking. What happened remains a mystery.

WelshHack

14th Jan 2018, 13:28

It must have been a very challenging evacuation. Kudos to the cabin crew.

LongJohn54

14th Jan 2018, 13:31

RVF750

14th Jan 2018, 13:35

VERY well spotted. Hmm. makes it look more fishy indeed.

2dPilot

14th Jan 2018, 13:58

I was about to say nonsense, but looking again at the picture in #23, it could be two people standing that I originally took for skid marks. And the line-up on those 'marks' don't seem to exactly match the subsequent 'obvious' wheel marks in the mud - but that could be just a perspective issue. Hopefully the full investigation (there will be of course?) will reveal more.

Avenger

14th Jan 2018, 14:01

The skid mark clearly shows the LH wheels were locked up at the point it departed. As for it being "taxi speed" complete nonsense, 737 would just stop at 15KTS taxi speed. The turning circle is to the RHS of the runway and there is no need to turn left before turning right the 737 can easily do this, even 747 land at Trabzon. Boeing perf tools give 1956 M with AB3 F30 and 1792M AB3 F40 at 63Tonnes with Anti Ice. ( landing weight based on ZFW plus min fuel and 162 pax). Nose Wheel steering is a low speed regime and won't cause the brakes to lock, so that's a red herring. The sensations the PAX describe of "speeding up" may equate to when the AB were disarmed. Non-standard RW CL lighting can be confusing. Deep landing with heavy left foot after disarming AB seems most likely, sadly. Several Turkish websites commenting on the "company culture" of putting crews under pressure. Notwithstanding any of this, our sympathy is with the aviators and we must remember we are all human.

sabenaboy

14th Jan 2018, 14:03

Yes, LongJohn54. Well spotted. There goes my speculation. :rolleyes:

HundredPercentPlease

14th Jan 2018, 14:07

The skid mark clearly shows the LH wheels were locked up at the point it departed.... (snip)

These remarkably humanoid "skid marks"?

http://i66.tinypic.com/dgtqg.jpg

turker339

14th Jan 2018, 14:13

Hydroplaning a la TAM 3054?

HundredPercentPlease

14th Jan 2018, 14:14

Landing video, allegedly:

https://www.youtube.com/watch?v=-aebRuMyrg4

OPENDOOR

14th Jan 2018, 14:17

Something caused the aircraft to suddenly swing left 35/45 degrees. The port wheels skid mark show the aircraft was travelling in a straight line when the wheels locked up for a short distance then rotated again before crossing the runway edge, which skid mark free. I suspect there might have been a problem with the nose-wheel steering. For the captain's sake I hope so.
Would starboard gear brake failure plus port side ABS activating account for the marks?

B2N2

14th Jan 2018, 14:23

Accidents rarely have a singular cause.
I’m going with WX at or slightly below mins, continue because of ground contact. ( I’ve never done that )
Slightly long landing ( never done that)
Slightly fast ( never done that)
Left reverser slow in stowing, wet 1000’ touchdown zone marker caused anti skid to cycle.
Pilot flying jabbed the brakes ( never done that either) and left they went.
I’ve had the anti skid cycle pretty aggressively crossing an intersecting runway after landing and one wheel went over the (wet from precip) centerline stripe and lost friction.
Anyway...my theory.

4runner

14th Jan 2018, 14:24

P2F “cadets” and Turkish astronauts?

pilotguy1222

14th Jan 2018, 15:00

This is the type of events that we will see (hopefully) at the end of this.

I feel it will be something more along the lines of an inadvertent power application. Either with forward thrust before both reversers were stowed, or asymmetrical thrust on the reversers.
The left turn is almost immediately after the td zone marking. Slippery when wet ( what B2N2 said)

Glad everyone was able to get out safe.

Heathrow Harry

14th Jan 2018, 15:32

"Cabin crew and services did a good job."

Superb jon TBH - amazing when you look at the angle plus the lack of outside lights etc etc

As we've said on the 2017 safety thread the line between a no-one killed and a dreadful disaster is often very thin - and this is about as close as it gets.

Mikter

14th Jan 2018, 15:35

My first post after lurking a long time ... where's the skid track of the nosewheel? If it's co-incident with either of the MLG tracks it must have been at a very odd angle. Airbourne?

GChopperP

14th Jan 2018, 15:42

Heard it might have been a bird strike, anyone confirm?

Kulverstukas

14th Jan 2018, 15:55

Landing video, allegedly:

Landing, cabin video, evacuation etc

fAHZKvnz3l8

finfly1

14th Jan 2018, 16:04

Any videos of the actual evacuation itself would be interesting, as it looks "challenging".

Again as I watch the video, I wonder why they don't turn off their strobes and emergency flashers once they are set at the scene. I would think their use would be distracting and disorienting for both rescuers and passengers.

Avenger

14th Jan 2018, 16:14

This is Turkey and I doubt the detailed investigation will ever surface beyond the desk top.

gearlever

14th Jan 2018, 16:36

Turkey is one of the few states who don't follow ICAO regs to publish Incidents and Accidents Reports.

gums

14th Jan 2018, 16:47

I would not rule out a no-kidding locked wheel due to a mechanical problem with the hydraulic brake actuators/cylinders, having had it happen to me.

Jet had been written up for anti-skid problems, but the real problem was the brake actuator(s). I had a bad habit of lightly tapping the brakes shortly after touch because I ran off the end one night and after that always wanted to make sure I had brakes. So the right main locked up at about 120 or 130 knots, ground off the tire and part of wheel assembly. Heh, quite a show for the tower folks and others.

The brake actuator(s) on that wheel never released due to a mechanical problem they discovered later. As someone mentioned, at high speeds rudder was effective, and then nosewheel steering for final few knots.

So a sudden lock up could be a big surprise, especially when about to use that turnaround pad. And they may have been well to the left of centerline getting ready for that 180 turn. So I am cutting the crew some serious slack.

Chesty Morgan

14th Jan 2018, 16:59

Dispatched with one of the reversers inop.

misd-agin

14th Jan 2018, 17:12

Most common observed acceleration on landing - rapid cancellation of reverse thrust while N1 is still above idle N1.

Abrupt cancellation of auto braking, followed by rapidly releasing that brake pressure, also feels like acceleration.

SamYeager

14th Jan 2018, 18:17

The voice recorder in this one will be really interesting.

What's the betting the breaker wasn't pulled and it's been overwritten?

gearlever

14th Jan 2018, 18:23

Turkish plane involved in an accident in Turkey....
CVR and FDR never ever will be published.

DaveReidUK

14th Jan 2018, 18:44

What's the betting the breaker wasn't pulled and it's been overwritten?

By subsequent sectors, you mean?

Musket90

14th Jan 2018, 19:11

Looks like for this airport they don't follow ICAO regs either for runway design. The steep slope looks to start about 60m from runway centreline. Isn't there supposed to be a runway safeguarded strip area in the region of 150m from centreline?

guadaMB

14th Jan 2018, 19:43

Heard it might have been a bird strike, anyone confirm?

That's been said on Spanish TV bulletins also, but...

What bird flies at MIDNIGHT?
Pegasus AC took land at 23:26 local time.

Airclues

14th Jan 2018, 19:45

In the video in post 43 there seems to be a flash during the landing roll. Could there have been a reverse surge on the right engine and the left engine remained in full reverse? In the early days of the 747, the P&W -3A engines were notorious for reverse surges. On a wet runway, if you didn't cancel the reverse immediately then you were off the side.

gearlever

14th Jan 2018, 20:12

Is there P2F at PEGASUS ?

hoss

14th Jan 2018, 20:20

My money is on crew safely decelerate the aircraft to taxi speed despite obvious landing roll distraction. **Both eyes inside cockpit**, L MLG veered in the grass and the rest of the aircraft follows, 10-15 knots would probably do in this case.

momo95

14th Jan 2018, 20:36

Is there P2F at PEGASUS ?

yes, they have many

Clandestino

14th Jan 2018, 20:36

So a sudden lock up could be a big surprise, especially when about to use that turnaround pad. And they may have been well to the left of centerline getting ready for that 180 turn. So I am cutting the crew some serious slack.
No need to get off the centerline if you want to use turning pad. Besides, I've seen a few turnarounds after landing on 11, some of them at the very close quarters, but none used a turning pad.

What's the betting the breaker wasn't pulled and it's been overwritten? Depending on the mod, CVR either stops at the engine shutdown or 10 mins later. Shutting down the engines via start levers and ensuring they stay off via fire switches is the part of the evac drill.

In the video in post 43 there seems to be a flash during the landing roll. As the video was shot from the cockpit of the plane waiting at HP 11, most probably it was wig-wag runway guard light.

Council Van

14th Jan 2018, 20:46

That's been said on Spanish TV bulletins also, but...

What bird flies at MIDNIGHT?
Pegasus AC took land at 23:26 local time.
Well I hit a bird at just after midnight at 20000 ft.

garpal gumnut

14th Jan 2018, 21:26

The Turkish authorities may very well need the assistance of the Egyptian Air Safety Committee to establish beyond doubt that the answer to the cause of this event is never adequately explained.

Tetsuo

14th Jan 2018, 21:35

Here is a video of another landing. As a SLF one does wonder about the plane turning left before making the 180 turn. Can it be that something went wrong while they were doing that? Maybe they were too fast while trying to make the left - right turn?

https://www.youtube.com/watch?v=JLA64B9Fzjc

lomapaseo

14th Jan 2018, 21:50

n the video in post 43 there seems to be a flash during the landing roll. Could there have been a reverse surge on the right engine and the left engine remained in full reverse? In the early days of the 747, the P&W -3A engines were notorious for reverse surges. On a wet runway, if you didn't cancel the reverse immediately then you were off the side.

Engine surging in reverse is typically caused by high EPR and low runway speed resulting in re-ingestion of the air blown forward by the reverser.

To me just an indicator of the workload in the cockpit at the time rather than a cause

Airclues

14th Jan 2018, 21:59

most probably it was wig-wag runway guard light.We will have to agree to differ. If you freeze the video at 0:10 you will see that the flash comes from the right side of the aircraft just ahead of the green nav light. It looks very much like a reverse surge to me. I have had quite a few of these and they are very distracting.

Engine surging in reverse is typically caused by high EPR and low runway speed

Surges can also be caused by bird strikes.

J.O.

15th Jan 2018, 02:00

After a period of sustained deceleration a significant reduction in the rate can feel like a speed up, for instance hitting a patch of standing water and aquaplaning...

Or maybe they were hearing the thrust increase with reverse selection?

Bomber Harris

15th Jan 2018, 03:31

I have seen bird strikes get caught up in the nose steering cables on 737’s before. The cables are exposed once the gear is extended. As stated previously when rudder effect reduces during deceleration, the (possibly) displaced nose wheel would start to have an effect.

Clandestino

15th Jan 2018, 03:46

We will have to agree to differ. If you freeze the video at 0:10 you will see that the flash comes from the right side of the aircraft just ahead of the green nav light. It looks very much like a reverse surge to me. I have had quite a few of these and they are very distracting.
After having a look at higher res screen, I stand quite corrected: the video was taken from the car and the flash I was referring to is actually a streetlight reflection in the right rear-view mirror as the camera pans over it. There is another flash in a single frame, though. Whatever it might be, it doesn't seem to make the aeroplane weer towards the Black Sea immediately.

latetonite

15th Jan 2018, 04:23

The OEI G/A performance is markedly better than 5% grad, not an issue. Ergo BKN 400 ft not an issue.

Not that it would had antything to do with an almost 20° veer-off 2400 m down the runway anyway.

I would not be so sure about that OEI going around meeting 5% climb gradient.:=

turker339

15th Jan 2018, 04:32

Is there P2F at PEGASUS ?

yes, they have many

How do you figure? PGS doesn't have a P2F option nor any crew that are P2F as a result. AFAIK.

MAN777

15th Jan 2018, 07:05

I wonder whether the extensive dumping of soft earth over the cliff has assisted in stopping the aircraft quickly, a sort of un-planned arrester bed ?

Volume

15th Jan 2018, 07:13

I wonder whether some scenario like on S7-778 may have happened (right T/R inop, forward thrust applied instead of reverse thrust...).
They obviously have to use full runway to do a 180° backtrack, so they may have stopped breaking and just "let it roll" some distance to quickly get to the turning area...

hoss183

15th Jan 2018, 07:18

Its clear it went over the edge with very little forward speed, or it would be a lot further down and more damaged.
My money is on - They were doing the backtrack turn (as post 70) and put the nosewheel on the grass, at that point they would have had no nosewheel steering to speak of. Then symmetric thrust just carried them straight on over the edge at taxi speed. Possibly combined with TR being taken out with remaining N1...

DaveReidUK

15th Jan 2018, 07:21

They obviously have to use full runway to do a 180° backtrack

No they don't.

While there is indeed a turning area at the end (enlarged recently), the video in post #70 clearly shows another Pegasus B738 performing a 180 on the runway itself (to save time?).

Avenger

15th Jan 2018, 07:33

Agreed, there is no need to use the pad. Most operators in Turkey use the runway, saves time and stops half the pax from standing up after touchdown! They were doing the backtrack turn (as post 70) and put the nosewheel on the grass, at that point they would have had no nosewheel steering to speak of. Then symmetric thrust just carried them straight on over the edge at taxi speed. Unlikely, the turn would be to the right then left, which would put the aircraft the other way round. Also there is a about 10 metres plus of land between the runway edge and the escarpment at Trabzon, hence if the nose wheel went on the mud, they would just stop. Turkish TV records passengers saying aircraft was sliding and twisting before a loud crash and rapid nose down attitude.

Killaroo

15th Jan 2018, 07:48

In the video in post 43 there seems to be a flash during the landing roll......

I agree. Appears to be an orange flash at the 19sec mark on that video.
Hard to say what, but an engine surge/stall is definitely a candidate.
Nasty dark wet night too, no doubt slippy runway.

OnTheNumbers

15th Jan 2018, 08:21

ThreeThreeMike

15th Jan 2018, 08:34

https://iasbh.tmgrup.com.tr/b40455/0/0/0/0/0/0?u=https://isbh.tmgrup.com.tr/sb/album/2018/01/14/trabzonda-faciadan-donuldu-gun-agarinca-ortaya-cikti-1515912424678.jpg

.

Lots of runway behind the aircraft.

MickG0105

15th Jan 2018, 08:43

Unlikely, the turn would be to the right then left, which would put the aircraft the other way round.

Have a look at the video at post #70, the initial turn is to the left and then back hard towards the right.

hoss183

15th Jan 2018, 08:45

A Unlikely, the turn would be to the right then left, which would put the aircraft the other way round.

No, have a look at the video in post #70, they perform a left swing followed by right backtrack, in almost exactly the same place as the accident.

RAT 5

15th Jan 2018, 08:54

I have seen bird strikes get caught up in the nose steering cables on 737’s before

Remember the KLM runway excursion in BCN due nose wheel steering malfunction.

I know bats are not strictly birds, but hey, they are nocturnal aviators.

Basil

15th Jan 2018, 08:56

Shearwaters fly at night, noisily congregating on cliff areas, but that's in the breeding season which I don't think is now.

They do migrate through Turkey but slightly later than this.

framer

15th Jan 2018, 08:58

The OEI G/A performance is markedly better than 5% grad, not an issue
It’s about 5% at MLW with 26k engine.

Avenger

15th Jan 2018, 09:28

No, have a look at the video in post #70, they perform a left swing followed by right backtrack, in almost exactly the same place as the accident. Just because this PGS does this, it doesn't mean its a procedure.Most aircraft making a normal touchdown can vacate at the second taxi way without backtrack. (plenty of you tube vids on this ) some make a move to parallel the centre line to the left before turning right, but its nothing like a sharp turn. We will know more tomorrow ;)

gearlever

15th Jan 2018, 09:46

OnTheNumbers

15th Jan 2018, 09:57

Someone in that company....

dongle

15th Jan 2018, 09:59

The word on the ground is an uncommanded thrust increase on engine 2 which took them off the runway

dongle

15th Jan 2018, 10:01

Also heard there are five recent occurences of the the same

DaveReidUK

15th Jan 2018, 10:04

Just because this PGS does this, it doesn't mean its a procedure. Most aircraft making a normal touchdown can vacate at the second taxi way without backtrack. (plenty of you tube vids on this ) some make a move to parallel the centre line to the left before turning right, but its nothing like a sharp turn.

I suppose it depends on your definition of "sharp turn". It looks like a standard 30° RET for traffic landing on 29, which makes it a 150° turn if you're coming from the 11 end.

But either way that's irrelevant, the debate was whether the incident was a 180 that went wrong, and your assertion that

Unlikely, the turn would be to the right then left, which would put the aircraft the other way round.

I'd suggest that, unless Pegasus is one of the few airlines that has paid Boeing the hefty premium to have the optional tiller on the RHS of the 737NG, a 180 will be in whichever direction the Captain decides to execute it.

Though if it was a runaway engine, it's all pretty academic.

Avenger

15th Jan 2018, 10:16

The turning issue is a bit of a red herring TBH, as observed, the Captain will decide according to his/her wishes. I am curious to understand how a 737NG can still have TOGA auto throttle more than 2 secs after ground air switch senses touchdown or with a TRA split of more than 10 degrees? This theory would mean they landed with the A/T armed and then somehow pressed TOGA before 2 secs and then selected asymmetric reverse? seems like far too may swiss cheese holes! Regarding info from "someone on the ground" having been based in Trabzon for 6 months I would take that with a very large pinch of salt..
Of course being Turkey its possible the Captain lit a cigarette and dropped it, lent forward to catch it and opened the T/L, after the Correndon fire at AYT due smoking we wouldn't be surprised!

Dongle..Can you provide refs for the uncommanded asymmetric TL movements please

Alex Whittingham

15th Jan 2018, 11:14

From an Indian news site:

The pilot, co-pilot and crew have now made statements to Trabzon prosecutors and both pilots passed breathalyzer tests, the Dogan news agency said.

"When we were going to make our usual manoeuvre towards the right from the seaside by reducing our speed, the right engine suddenly gained speed for a reason we do not know," the pilot was quoted as telling the prosecutors.

"Due to this speed, the plane got out of our control and suddenly swung to the left and got stuck into the mud in the cliff."

www.ndtv.com (https://www.ndtv.com/world-news/stricken-turkey-plane-suffered-sudden-engine-surge-pilot-1800216)

syamaner

15th Jan 2018, 11:16

First Officer is pf, weather is at minimums. They are expecting to see the runway at minimums. At minimums they see the runway and the first officer disangages the autopilot but at the same time he presses the toga buttons. Captain takes over and lowers the nose and retards both thrust levers to idle, they land at idle thrust and aircraft was dispatched with one reverser inop. The captain deploys the thrust reverser of the left engine and releases the right engine. Since he hadn't disconnect the auto throttle right engine goes to TOGA thrust. Aircraft starts to accelerate and skids off the runway from the left. Right engine saparates. All passengers evacuate the aircraft from the rear door. No smoke in the cabin no injuries.

During landing phase, the aircraft systems receive an "on the ground" information from the Flt/Gnd switches, spoilers are deployed, left engine reverse thrust applied. If in this situation the A/T can command TO/GA thrust on a single engine, I would say that this a serious design flaw.

As far as I know, if the aircraft has been dispatched with the right reverse inop, the reverse mechanism will be locked by the technical staff and if the pilot activates the reverse thrust levers only the left engine would go to reverse mode. Would a pilot in such a situation pull only the left reverse lever or both (instinctively)? Or is there a defined procedure which prohibits the pilots to activate an inoperative reverse thrust lever during landing?

Why I am asking this?

Let's say that the captain as taken over the controls and landed the aircraft safely. If he would activate both reversers the autothrottle would not be able to advance the right thrust lever to TO/GA thrust position because the pilots right hand pulls the levers back. Only after cancelling the reverse thrust the captain can remove his right hand from the throttle. By this time the aircraft must have decelerated to 60 kts. Let's say the right engine goes to TO/GA mode at this point. It would take a couple of seconds for the full thrust to developed. During this time the pilots should have noticed this problem and retarded the thrust levers (in my opinion).

PILOTINHO

15th Jan 2018, 11:48

Post 23 Quote-
The skid mark that can still be seen on the runway (picture below) already has a large angle from the runway centerline.
-Quote

I cannot see any skid marks on the runway. Watching the video posted earlier you can see two people walking along the runway and that is what is being mistaken for skid marks.
This photo is taken from the beginning of the video.

I searched in google aquaplaning marks on runways and believe me from the pictures I saw isn’t easy to see them unless a good closeup picture is taken; which make sense because aquaplaning is the fenomena when the tires detach from the runway for a x time. I think from this pictures is difficult to see them. Less wait for a closer picture of the runway.

Mikehotel152

15th Jan 2018, 12:01

I am curious to understand how a 737NG can still have TOGA auto throttle more than 2 secs after ground air switch senses touchdown or with a TRA split of more than 10 degrees?

Even if they touched down long, they clearly managed to maintain the centreline for quite some time before making an unplanned trip to the beach. The theory doesn't hold water.

Perhaps the pilot taxied to the left of the runway in order to execute a right turn, with the intention of using thrust from the no.1 engine to assist the right turn, with steering from the nose wheel, which lost traction as he inadvertently pushed the no.2 thrust lever forward... But that's pure speculation.

Avenger

15th Jan 2018, 12:40

If it is uncommanded thrust without lever movement this is a real headache for CFM and Boeing. I say without lever movement as the crew could just close the thrust lever and the problems gone. Normally EEC faults or HMU faults do not give this type of result, lets see what the black box says...

RAT 5

15th Jan 2018, 13:16

If it is uncommanded thrust without lever movement this is a real headache for CFM and Boeing.

Lots of ifs so far. They've got the crew, all the digi boxes and a reasonably intact a/c. It shouldn't take a Sherlock.

Airclues

15th Jan 2018, 13:32

Jet that shot off Trabzon Airport runway 'had power surge' | Daily Mail Online (http://www.dailymail.co.uk/news/article-5270233/Jet-shot-Turkish-runway-engine-power-surge.html)

esenuslu

15th Jan 2018, 13:34

Two telescopic cranes seen in the picture were used to remove the cabin baggage.
The airport authority awaits a heavy-lifting crane to remove the plane, and constructing a stable platform for such a crane is underway.
Please see the NTV news channel for the pictures <ntv.com.tr>

hoss183

15th Jan 2018, 13:48

It funny how 'mysterious' gets used when the involved describe an accident. As several people have speculated, its going to be one of:
a) Deselection of TR before N1 low enough and asymmetric TR stowing
b) No2 TR was INOP and power was put on No2 for some reason, as per above theories
c) PF was using asymmetric thrust to turn and pushed the wrong lever

I'll put money its not a completely uncommanded power-up.

DaveReidUK

15th Jan 2018, 14:02

Jet that shot off Trabzon Airport runway 'had power surge' | Daily Mail Online (http://www.dailymail.co.uk/news/article-5270233/Jet-shot-Turkish-runway-engine-power-surge.html)

Nothing new there, appears to be just a rehash of the same AFP-sourced article linked in post #100, suitably dumbed-down for Daily Mail readers.

RVF750

15th Jan 2018, 16:36

Just to put a few theories to bed. 1. Captain only steering on almost all 737s. You go left because you can see the edge better and judge it. Simples.

Steering. I've had a couple of big birds in the nose gear and the cables and NWS still worked.

It is easy (especially for crew who've flown non Boeings before to inadvertently push TOGA when you want to disconnect the autothrottle. Happened countless times before over the years and will again. If you do it, a quick expletive and then press the disconnect before thrust rises and it's not a safety issue. Pulling back the levers and not disconnecting is another matter....

Mikehotel152

15th Jan 2018, 16:59

and physically hold both of them closed against the servos all the way to the flare; then hold them closed all the way down the runway until releasing just one of them prior to the excursion?

tdracer

15th Jan 2018, 18:31

There have been a few excursions in the past where the pilot inadvertently advanced one throttle in forward while working the reverse levers on the other engines - although these have been on four engine aircraft, not twins (at least the ones I'm familiar with).
But it's at least a possibility that if the pilot didn't pull the reverser lever on the deactivated right engine, they inadvertently advanced the forward thrust lever on the right when de-selecting the left reverse lever.
A totally uncommanded thrust advance (Uncontrollable High Thrust or UHT in the lingo) is extremely rare on FADEC engines (something like 1/100,000,000 per engine flight hour), but it has been known to happen. It was more common with the pre-FADEC cable engines - usually due to a broken throttle cable...

RAT 5

15th Jan 2018, 18:33

They appear to be so far down the runway that we must assume the TR's had been deployed. If so, that is a not starter for cause. They must have been at a slow taxi speed by this point, so I suspect asymmetric reverse thrust would not cause this. Broken nose wheel steering might give an idea, but at slow speed the brakes should stop it PDQ, but startle WTF factor would delay size 12's entering the equation.

747-8driver

15th Jan 2018, 18:42

TDRACER, looks like it did happen on a twin: https://en.wikipedia.org/wiki/TAM_Airlines_Flight_3054

EGPFlyer

15th Jan 2018, 18:57

That wasn’t uncommanded.. they never closed one of the thrust levers

D-OCHO

15th Jan 2018, 19:07

In the company I fly for as a Captain on the 737NG 7/800 we had an aircraft which would not reduce thrust below +/- 60% when starting descent. It would show retard and the thrustlever would move to the idle position but the N1 would not reduce below 60% on one engine. It took a couple of manual thrust applications and retards to get the thrust to decrease to idle. It was a real headache for maintenance because it was initially verry intermittent and not obvious until you had a good look at it.

Herod

15th Jan 2018, 19:55

There is a lot of talk here about one TR being inop and locked. I can't find the original mention of this in the thread. Can anyone point me to it please? Or is everyone following the herd?

BillSouth

15th Jan 2018, 20:04

There is a lot of talk here about one TR being inop and locked.

It's not TR related issue, as too far down the runway at taxi speed.

Chesty Morgan

15th Jan 2018, 20:16

Herod, I heard it from a friend who works there. It is definitive. Sorry can’t link to someone’s head :p

Tom Cundall

15th Jan 2018, 20:22

I managed to get a tiny stone stuck in the nose wheel steering cable pulley on a 757 that got stuck in a hard left turn just south of the tower (Romeo one?) at Gatwick a few years ago. The stone, perhaps 1/4 inch diameter had been dragged into the pulley and was holding the cable fast.
The Skipper suddenly bent double and made some deep grunting noises as he tried to turn the handle. I thought he was having a heart attack so I shouted that I was taking control and stuck the brakes on. Broad daylight but still plenty of confusion.

I wonder if the same thing happened here?

Avenger

15th Jan 2018, 21:56

Initial investigations seem to find the aircraft could not maintain the centre line, drifted to the left and the left gear entered the soft ground and collapsed resulting in a sharp yaw to the left, apparently compounded by right engine power. Prior to touchdown there is suggestion the the FO was pf and elected to GA, pressed TOGA but Captain took control and landed. Maybe asymmetric reverse, but looking at the pictures it is closed, which suggests any asymmetric reverse was cancelled prior to the skid, apparently most of the investigation is complete, which suggests the causes have been positively identified. Just for info, the LD with AB3 F30 1874 AB2 F30 2417 with one reverser inoperative, or 2197 AB2, 1708 AB3 same condition. If the aircraft touched down deep this may explain why they are close to the end at the time of the incident. The waters are really getting muddy!

gearlever

15th Jan 2018, 22:08

The Flap Lever on 737 is very close to throttle #2.
After Landing Items: Selecting the flap lever up and striking throttle #2 unintentionally ?

jimjim1

16th Jan 2018, 02:40

Incident may have similarities with these -
747-8driver mentioned one of them.

Both fly by wire Airbusses, twins with one thrust reverser known to be inoperable and an elevated thrust after touchdown from the non-reversed engine.

[1]
March 22, 1998
Airbus A320-214
Fatalities 3 on ground

https://en.wikipedia.org/wiki/Philippine_Airlines_Flight_137
http://www.rvs.uni-bielefeld.de/publications/compendium/incidents_and_accidents/BacolodReport.pdf

"condition of the aircraft immediately upon touch down with No. 1 engine reverse inoperative, thereby causing an adverse flight condition of extreme differential power application during the landing roll resulting in runway excursion and finally an overshoot"

"3) Review the Airbus A320 flight technique for landing with one engine reverse inoperative, amend/revise as necessary;"

[2]
July 17, 2007
Airbus A320-233
Fatalities 199 (all 187 on board; 12 on the ground)

https://en.wikipedia.org/wiki/TAM_Airlines_Flight_3054
https://web.archive.org/web/20110706160801/http://www.cenipa.aer.mil.br/cenipa/paginas/relatorios/pdf/3054ing.pdf
http://www.dailymotion.com/video/x4m6hr1 -- Mayday _ Air Crash Investigation S11E01 - Deadly Reputation (TAM Airlines Flight 3054)

"The deactivated thrust reverser on the number 2 engine was confirmed"

"the flight computer recorded the left thrust lever being retarded to the rear-most position, activating the thrust reverser on the left engine, while the right thrust lever (controlling the engine with the disabled thrust reverser) remained in the CL position."

"As a matter of fact, there are various reports of errors in the execution of the pinned
reverser landing procedures, and these incidents are not restricted to the aircraft of this
manufacturer. It is a problem that occurs throughout the aircraft industry. "

smiling monkey

16th Jan 2018, 03:13

Prior to touchdown there is suggestion the the FO was pf and elected to GA, pressed TOGA but Captain took control and landed.

If that was what happened, then it's not the first time a runway excursion incident has resulted from a go-around aborted by the captain when the FO was PF. QF 1 at Bangkok in 1999 was in similar circumstances. Aborted go-arounds are never a good idea.

hoss183

16th Jan 2018, 09:34

There is a lot of talk here about one TR being inop and locked. I can't find the original mention of this in the thread. Can anyone point me to it please? Or is everyone following the herd?

Post #56 Chesty "Dispatched with one of the reversers inop."
Dont know if that is a guess or a statement though.

Nil further

16th Jan 2018, 10:00

No point in quoting 320 stuff ,it’s irrelevent .totally different philosophy .

I’ve flown both (lots)

RVF750

16th Jan 2018, 11:32

Reverser inop on a 738 is a set of locking pins poking out of hte nacelle and a lockwired reverse lever. You certainly can't move it easily!

Future Rodney King

16th Jan 2018, 11:50

and physically hold both of them closed against the servos all the way to the flare; then hold them closed all the way down the runway until releasing just one of them prior to the excursion?

Wont/shouldn’t happen. Auto throttle disengagement occurs 2 seconds after touchdown. Now whether they pressed TOGA on the deck after TD prior 2 seconds is another matter, I suppose then, they could have held the thrust levers at idle.

Nothrills

16th Jan 2018, 11:56

A question from SLF: with so many accidents related to one of the reversers inoperative, why is it still allowed to operate aircraft in such condition?

RVF750

16th Jan 2018, 12:22

It happens. Reverser inop operations occur every day, all over the globe and have done since the 707. Usually it's a non event. Don't worry yourself.

A0283

16th Jan 2018, 12:26

Grossly simplifying it ...and in general ... Inop is allowed because the thrustreversers are technically an 'extra'. Operationally you could/should be able to do without them. You might take a look for example at how required landing distances are calculated for each flight.

You might say that is from a safety point of view. But add to that that a 'braking' backup is 'nice'.

From an operational point of view there are advantages in 'taking an exit earlier'.

With Murhpy in mind you might say that every added feature creates added types of errors, incidents and accidents. That is true for basic and safety features. Like an ELT (battery) malfunction burning a hole through a 787 fuselage. Or an escape slide inflating inside the cabin and blocking an exit.

So Murphy is not surprised that a reverser inop with a potential asymmetry can lead to an actual asymmetry event. In spite of the multiple layers of defensive safeguards.

Overall the balance is positive, thats why they are on, and why you are allowed to fly with one locked under specified conditions and procedures.

Again, grossly simplified, but hope it gives an idea about some of the factors involved.

aterpster

16th Jan 2018, 13:42

Overall the balance is positive, thats why they are on, and why you are allowed to fly with one locked under specified conditions and procedures.

Correct. T/Rs are not allowed to be used in certification of landing distance. But, they are nonetheless certified required equipment. Some operators elect to limited dispatch with one T/R inoperative on a two engine airplane.

When landing on a contaminated runway with one locked, you have to be on your "A" game.

notfred

16th Jan 2018, 13:42

Given that any thrust reversers are a "bonus" in the landing, why make it asymmetric? Wouldn't the handling be easier to say all working or all non-working?

misd-agin

16th Jan 2018, 14:49

Differential thrust with one inoperative thrust reverser isn't a big deal. It's something to be aware of but not something to be afraid of.

A damp runway isn't contaminated. With contaminated runways, with snow, sleet, slush, on the runway, you need to be very careful using differential thrust. The MEL may prohibit operation into contaminated runways with an inoperative thrust reverser.

It's hard to understand how an engine power was advanced enough to cause a runway excursion. It happened. Professional pilots are puzzled since the Captain's hand is typically on the throttles ensuring that they're at idle and remain at idle.

RAT 5

16th Jan 2018, 15:32

Differential thrust with one inoperative thrust reverser isn't a big deal. It's something to be aware of but not something to be afraid of.

It helps if you let the auto brakes do their thing and not disconnect too early; then all you have to do is steer with your feet: heels on the ground. Considering the length of the runway, and the need for 180, there should not be any need to disconnect the AB's. I'm not understanding the thoughts about mis-selecting TOGA, or flaps up knocking the Rt. TL to forward thrust, or some other curious 'what ifs'. They were so far down the runway, and judging by the tip over the edge, they must have been going quite slowly and just nudged over the edge, otherwise they were swimming. The skid marks from the mains suggest some heavy stopping forces. As has been said, the investigators have all the info they could wish for and must surely have the answers. When will they tell the rest of us is the question.

FCeng84

16th Jan 2018, 15:50

It is curious to me that the tracks across the grass from where the airplane apparently departed the runway pavement to the edge of the down-sloping bank seem to be very straight. That indicates to me that whatever forces caused the yawing moment resulting in the deviation from runway centerline were active only when the airplane was on the runway and did not continue as it crossed the grass. If the problem resulted from stuck nose gear steering or asymmetric thrust I would think that the track across the grass would be curved. It is possible, however, that turning side force from a stuck nose gear would not continue onto the soft margin if the nose gear stopped rolling as it dug into to the dirt. Even if that were the case, I would think that an airplane departing the runway with any significant yaw rate would exhibit continued yaw motion (and thus curved tracks) during at least the first part of its motion off the edge of the runway.

I sure hope those data and voice recorders are released so that we can learn from this incident and reduce the likelihood of a repeat.

aterpster

16th Jan 2018, 16:19

Given that any thrust reversers are a "bonus" in the landing, why make it asymmetric? Wouldn't the handling be easier to say all working or all non-working?
Nope. You use the working one carefully...using less reverse thrust than when both are operating.

Avenger

16th Jan 2018, 16:19

For once the Turkish Authorities are caught between a rock and a hard place. Normally we never get to hear the results of the investigations and Ali Sabanci won't want the "pegasus family" hung out to dry. On the other hand Boeing and CFM face severe commercial pressure to publish the results lest there is a call for CFM engined A/c and NGs to be grounded pending the resolution. Boeing stated uncommanded thrust INCREASE is a 1/100,000,000 hrs event, on the other hand DECREASES on thrust are quite common especially at high power in the climb. The Facts as we know them are: Cloudbase was below minima, FO was PF for most of the approach, Reverse was selected, and the centre line track not maintained after landing. From the "Flying Horses mouth" FO elected to GA and the flight somehow landed. Given the harsh regime in Turkey we are not surprised by the Pilot statements to the prosecutors, however, this event could have been a huge loss of life and the authorities have a duty to release the info, and in a timely manner. Good job its not US all PAX would be finding a lawyer by now..

DaveReidUK

16th Jan 2018, 16:42

I think you have things back-to-front.

There is no smoking gun implicating an uncommanded power increase. At this stage it is simply one of a number of hypotheses.

In the absence of that, there won't be any AD or fleet grounding.

lomapaseo

16th Jan 2018, 18:05

Boeing and CFM face severe commercial pressure to publish the results

The only commercial pressure is to publish any corrective actions pertianing to their product.

the absence of such speaks to the problem elsewhere in a final report, if any, by the authorities involved.

wingview

16th Jan 2018, 21:37

If a TR was inop it must have been the #1, the one in the pond is wide open. That rock at #1 was the life saver probably. Mis fortune and fortune in a couple of seconds.

Chu Chu

16th Jan 2018, 22:44

FCeng -- Conversely, the aircraft wouldn't have stayed on the runway very long with half, or even a quarter, of the heading deviation shown by those tracks. So there had to be a pretty significant yaw rate not long before the wheels hit the grass

b1lanc

17th Jan 2018, 00:30

It is curious to me that the tracks across the grass from where the airplane apparently departed the runway pavement to the edge of the down-sloping bank seem to be very straight.
Particularly since the Capt allegedly said (reported on another site) that the "right hand engine accelerated when the aircraft was already off the left edge or the runway." If true, I should think they would be in the drink.

Avenger

17th Jan 2018, 01:09

The only smoking gun being the combined pilot testimony to the prosecutor !

Volume

17th Jan 2018, 06:43

Grossly simplifying it ...and in general ... Inop is allowed because the thrustreversers are technically an 'extra'. Inop is not the issue, but one single T/R inop. Russia expliciltly banned it after the S7 Accident in Irkutsk, it´s either both or none.

Not because it is a general issue as a single event, but it can bite you if something else goes wrong.

Kulwin Park

17th Jan 2018, 08:09

Has the jet been removed yet? Is there pics of it?
Just wondering how they'll get that up in one piece and fly it out?

hoss183

17th Jan 2018, 08:17

That wont be flying out, very surprised if its not a write off.

Kulverstukas

17th Jan 2018, 12:50

It was confirmed on FS that if perform landing with TOGA armed and one reverse inop AT will not switch off even with difference in throttles positions.

Right Hand Thread

17th Jan 2018, 14:21

Has the jet been removed yet? Is there pics of it?
Just wondering how they'll get that up in one piece and fly it out?

Some advice:

1) Take another look at the photos, particularly the one with the engine lying in the sea.

2) Re-read your post.

3) Quietly leave this thread and hope nobody else noticed.

fox niner

17th Jan 2018, 14:23

Thanks kulverstukas.
If that is what happened here, that would certainly warrant an AD. However, the Turks don’t adhere to Annex 13, and it is doubtful we will hear anything again about this accident.

Avenger

17th Jan 2018, 15:44

It was confirmed on FS that if perform landing with TOGA armed and one reverse inop AT will not switch off even with difference in throttles positions.

TOGA "armed" ? Auto throttle armed and TOGA selected? please explain the config, thanks

RVF750

17th Jan 2018, 19:09

I saw the Video, it appears to be an approved full flight simulator. Turkish Training Captain, talking through the actions and achieving the same result, off the side at slow speed.

sonicbum

17th Jan 2018, 21:04

Any link ?

BluSdUp

17th Jan 2018, 21:23

This is warning nr 1 from Murphy.
What a spectacular hint!
The fact that they all crawled away, is in my book symbolic!

The CAAs of the world and NTSBs alike must take note.
I did mention with regards to no fatalities on large passenger jet transport in 2017 that I find it amassing, considering what goes on every day and the falling quality of operating crew and regulatory incompetence.That we do not have weekly hull losses and monthly fatal ones!

I am afraid 2017 was just a statistic hick up.

Anyway
I bet my right hand engine at V1 that IceMan and Goose messed it up.
IF one engine had an Inop reverser , for sure.
It is no big deal, but has a few potential pitfalls as duely demonstrated.
As I have mentioned the Old Girl is a performer, but if not treated right the will slap and leave you in tears.
One thing , she is fast. Was this a F40 or did they do a normal F30 landing.

Standing by for next warning.

Domi

17th Jan 2018, 21:53

Any link ?

https://youtu.be/aTuDmYs1Q68

reverserunlocked

17th Jan 2018, 21:53

Looks rather farcical to me. www.facebook.com/story.php?story_fbid=10155375957268865&id=786678864&_rdr

flyingchanges

17th Jan 2018, 23:33

off the side at slow speed.

That sim video was not a low speed excursion.

Bleve

18th Jan 2018, 01:53

poldek77

18th Jan 2018, 05:34

Has the jet been removed yet? Is there pics of it?
Just wondering how they'll get that up in one piece and fly it out?

Maybe they will try to do it today:

A0333/18 NOTAMN
Q) LTAA/QMRLC/IV/NBO/A /000/999/4100N03947E005
A) LTCG B) 1801180100 C) 1801190100
E) RWY 11/29 CLOSED TO TRAFFIC.

gearlever

18th Jan 2018, 07:05

Advancing any throttle and flaps in ldg position would mean an unsafe T/O alert.
Wouldn't it?

RAT 5

18th Jan 2018, 09:05

The captain deploys the thrust reverser of the left engine and releases the right engine. Since he hadn't disconnect the auto throttle right engine goes to TOGA thrust.

I doubt you're be able to select TR's with TOGA still engaged; both technically, i.e. various lock outs, and the left TL trying to go to TOGA and you holding it against the clutches.

Hm? Not sure about the theory.

Bleve

18th Jan 2018, 09:19

Advancing any throttle and flaps in ldg position would mean an unsafe T/O alert.
Wouldn't it?

Yes:
Takeoff configuration warning is armed when the airplane is on the ground and either or both forward thrust levers are advanced for takeoff. Takeoff configuration warning activates if:
• trailing edge flaps are not in the flaps 1 through 25 takeoff range.

If you watch the simulator reconstruction of the event (posted above), you can see that after touchdown, the PF removes his hand from the Right Thrust Lever to deploy the Left Thrust Reversor (the Right Thrust Reversor is inop). Because TOGA had been inadvertently selected and the Autothrottle was still engaged, as soon as the PF’s hand came off the Right TL, the Right TL advanced to TOGA Thrust and the Takeoff Configuration Warning activated.

hoss183

18th Jan 2018, 13:02

Interesting, they spent some time with is suspended, possibly checking LG or locking it down, and now it seems to be standing on its own LG. Quite surprised those were not damaged enough to prevent that.
Edit - ok looked back at vid, Left MLG looks intact but right has been ripped off. They are prepping a tug and bogie truck i guess to support under the right wing.

RAT 5

18th Jan 2018, 13:12

Because TOGA had been inadvertently selected and the Autothrottle was still engaged,

Why was the AT still engaged at touchdown? Was the an autoload?

birmingham

18th Jan 2018, 14:56

Yes:

If you watch the simulator reconstruction of the event (posted above), you can see that after touchdown, the PF removes his hand from the Right Thrust Lever to deploy the Left Thrust Reversor (the Right Thrust Reversor is inop). Because TOGA had been inadvertently selected and the Autothrottle was still engaged, as soon as the PF’s hand came off the Right TL, the Right TL advanced to TOGA Thrust and the Takeoff Configuration Warning activated.

If I remember correctly after TAM at Sao Paulo, Airbus reviewed procedures for a single TR inop and put out guidance that both levers should be fully retarded, thereby on a bus, cancelling the autothrottle. This was done, specifically to prevent runway excursions in the event the autothrottle had been accidentally been left in TOGA or CLM. This was seen as a procedural belt and braces beyond the various systemised safeguards.

In the 737 video the captain selects reverse for No 1, having left the autothrottle in TOGA, which produces an autothrottle commanded spool to N1 on No 2. if, and I mean if, the rumours are correct this will probably turn out to be a primary cause of the accident.

However, Boeing or Airbus, rumours true or otherwise, whenever a single TR is inop it seems to me that;

(1) If possible you would plan to land brakes only or
(2) If not possible/desirable you would have a heightened awareness of the interplay between the TR and associated systems such as spoilers and AT.

Either way the deployment of asymmetrical reverse thrust would feature significantly in the briefing.

As is usually the case additional pressures such as the cancelled go around, late decision height etc. seem to have contributed in lining up the holes. Hindsight is a great thing, but it now seems overriding the PF wasn't the smartest thing to do here. A go around together with second go at the landing config and briefing would have almost certainly saved the day.

latetonite

18th Jan 2018, 15:19

The autothrottle in the B737 automaticly disengages two seconds after touchdown, provided is was armed. (Autoland or 'speed mode').
Also if there would be a split thust lever position, or a malfunction in the system was discovered, disconnect of the A/T would occur.

So much for the TOGA/GA 'armed' conspiracies.

gearlever

18th Jan 2018, 15:28

If and I say IF the video is about right, the unsafe take off alert sounded for about 30 sec until the end without any reaction of the crew.

Bleve

18th Jan 2018, 15:29

Why was the AT still engaged at touchdown?

I think that is the root cause of the problem. If the outline of the accident as posted by OnTheNumbers is correct (the video reconstruction strongly suggests that it is), then the problem began when they transitioned to a visual approached and the F/O disconnected the automatics for a manual landing. But instead of disconnecting the AT, he pressed TOGA instead. The CPT took over, but never corrected the first error by disengaging the AT.

gearlever

18th Jan 2018, 15:35

Manual flight = Manual thrust !

(My choice)

latetonite

18th Jan 2018, 15:53

I think that is the root cause of the problem. If the outline of the accident as posted by OnTheNumbers is correct (the video reconstruction strongly suggests that it is), then the problem began when they transitioned to a visual approached and the F/O disconnected the automatics for a manual landing. But instead of disconnecting the AT, he pressed TOGA instead. The CPT took over, but never corrected the first error by disengaging the AT.

If people would verify the FMA, and be able to know what those things mean, this would not happen. Also, that captain must have had a weird looking FD in front of him.
On the other hand, in a time where I do not get a satisfactory answer from captains doing recurrent training, of the mechanics of 'Level Change', I am not easily surprised anymore.

wiggy

18th Jan 2018, 16:21

A couple of points to add to the debate as a FWIW from a generic Boeing POV:..

1. The 777 has in part the following Autothrottle logic:

Autothrottle disconnect occurs automatically:......
when either reverse thrust lever is raised to reverse idle
........

I have yet to find chapter and verse (if it exists) of whether that logic still applies in the event a reverse lever being raised after TOGA has been pressed.

Secondly there is a still current Ops manual Bulletin for the 777 from about two-three years back warning of :”Uncommanded Autothrottle Movement on the Ground”..which stated that “there have been reports of uncommanded Autothrottle advancement during ground operations.......In one report the autothrottles advanced after landing before speed brakes were retracted”

So, having thrown that into the mix do we still want to rush to hang the P1 of this 737 out to dry ? More importantly and obviously of more relevance is does anyone know and able to post what the 737-800 FCOM says if anything on this subject?

syamaner

18th Jan 2018, 16:51

737 NG FCOM states that 2 seconds after touchdown A/T would disarm.

birmingham

18th Jan 2018, 17:04

No official confirmation of anything as yet. Even the inop thrust reverser is not confirmed. All the official sources have done is said the crew were sober and had difficulty braking on the wet runway

Chesty Morgan

18th Jan 2018, 17:23

RVF750

18th Jan 2018, 17:36

To be fair, all they can hang the P1 on is taking over after a GA has been called and reversing the decision. I doubt he may have known the TOGA had been selected as he'd have had his eyes outside, would have pulled the levers back sharply and if single channel the autopilot disconnect wail is quite loud.

Having landed, either the A/T logic thinking it's in a Go around situation discounted the air/ground logic and 2 second cut out or a fault, may well have accounted for the thrust.

It was dark, poor vis and wet, not ideal conditions to see the lever move up, or fully be aware of the noise of a spooled up engine. Most of the 737 Pilots in Turkey seem to use Bose A20 headsets as well.

Remember the CRM gem of counting ball throws as bloke in the gorilla suit runs behind? So concentrated most don't even see him.

Perhaps the T/O Config horn falls under that chapter.

Food for thought. And a definite Swiss Cheese event if there ever was one!

Mikehotel152

18th Jan 2018, 18:16

Nah. I don't buy that at all.

TOGA thrust on a 738 produces a massive surge in power and pitch up. There is no way a competent pilot could take control and not notice, let alone hold the thrust levers shut against the servos and not notice, and nor is it feasible that a pilot of any experience level could fail to notice one engine producing max reverse thrust while the other is producing TOGA thrust; the yaw shortly after touchdown would be massive and they would have exited stage left far earlier in the landing roll if that had occured.

gearlever

18th Jan 2018, 18:21

Spot on:ok:

I feel the same way. Don't know 737 but have some hours/years on A320 and A300/310.

syamaner

18th Jan 2018, 19:00

Another theroy:

The aircraft landed in TO/GA mode. As it was in TOGA mode, the A/T logic didn't take into account that the aircraft was on the ground (it is not uncommon to touch the runway during a GA). As the aircraft was in TO/GA mode the TR of the left engine didn't activate in spite of lever movement. (Is this possible???). Additionally the right engine needed time for spool up.
So, no TR on the left engine and slowly spooling up turbine of the right engine may have prevented the expected massive yaw during the initial phase of the landing roll.

flyingchanges

18th Jan 2018, 19:30

Don't know about the rest of the world, but for us,

transfer of ac below 500' = GA

the increase in thrust from pressing GA would have resulted in an unstable approach = GA

Simplythebeast

18th Jan 2018, 20:01

Airlive providing this quote from the pilot...
“The plane made a normal landing. Once we came to the end of the runway, we tried to maneuver to the right. Just as we were about to maneuver, the right aircraft engine started to accelerate. The plane should have gone right, but because of the right engine, it suddenly started going leftwards and went down the slope in the direction of the [Black] Sea,” .

sonicbum

18th Jan 2018, 20:50

Mikehotel152

Totally agree with the above as well. There must be something else into the equation.

sonicbum

18th Jan 2018, 20:55

To be fair, all they can hang the P1 on is taking over after a GA has been called and reversing the decision.

Is this the case ? I understood the FO mistakenly pushed the TOGA Pb instead of disengaging the A/T (commom error) and the CP took over quickly but forgot to disengage the A/T.

Centaurus

18th Jan 2018, 23:20

Turkish Training Captain, talking through the actions and achieving the same result, off the side at slow speed

Talking to a F/O the other day who flies the A330 for same airline. (I think) The Middle Eastern airline he works for has a no manual flying policy meaning full automatics down to 300 ft even on visual approaches. On one occasion the PF in the RH seat was on the visual approach to an ILS runway and coupled.

At 1000 ft he disengaged the AP in order to continue to fly the approach manually. The captain immediately remonstrated with him and re-engaged the AP by now the aircraft was at 800 ft on short final. A few seconds later he allowed the PF to disengage the AP at 300 ft so he could land manually.
All this shenanigans below 1000 ft in clear weather simply to meet a ridiculous SOP against manual flight. Common sense goes right out of the window with some of these operators:ugh:

Capn Bloggs

19th Jan 2018, 01:52

Nifty timelapse of the recovery here:

Pegasus Airlines plane recovered from Turkey airport cliff edge using crane - ABC News (Australian Broadcasting Corporation) (http://www.abc.net.au/news/2018-01-19/turkey-crane-used-to-remove-pegasus-plane-from-cliff/9342278)

Avenger

19th Jan 2018, 05:51

Is this the case ? I understood the FO mistakenly pushed the TOGA Pb instead of disengaging the A/T (commom error) and the CP took over quickly but forgot to disengage the A/T.
Nope, FO wanted to Go Around due lack of required visual ref bye Captain decided to take over and land.. there is a big difference. If you simply disconnect the AP and hold the thrust levers closed against the servos and land deep and hard....the rest is history.
Talking to a F/O the other day who flies the A330 for same airline.They don't have 330.
Coupled approaches are limited to 3.25 degree glide and Trabzon is more than this so its not possible.
There are no SOPS preventing manual flight but on a heavy it is not advised to disengage the automatics too early, on the other and the loss of manual flying skills are well documented.
Doubt we will ever get to the bottom of this incident

misd-agin

19th Jan 2018, 07:38

“but on a heavy it is not advised to disengage the automatics too early, ”

Do ‘ heavy’ aircraft fly strangely different than regular airliners if the autothrottles, or other automatics, are disconnected ‘too’ early?

And where is ‘too early’?

RAT 5

19th Jan 2018, 07:44

Does that mean they ground the a/c if AP's are u/s? Do they land at 'nearest suitable' if the AP fails in flight? Don't say it can't because a friend of mine could not engage AP on A340 from LHR to Mauritius. They took it in turns to fly and arrived on time in the sunshine. My mate was old school.

BraceBrace

19th Jan 2018, 08:26

In a world where we are facing harder and harder battles to protect us from the "office" people because ... our job "ever changing dynamic environment" is pretty hard to explain (nothing against them), it is pretty impressive to see how we are pretty easy in doing the same thing as office people if we're not in the same company/country.

We are all a result of our training.

Cough

19th Jan 2018, 10:55

Too early is before you exit RVSM levels....

sleeper

19th Jan 2018, 11:55

I flew "heavies" the last 12 years before retirement and usually flew manual, autothrust off, below 10000 feet. No big deal unless offcourse you never do this.

donotdespisethesnake

19th Jan 2018, 12:24

According to Turkish media, the recovery was completed by 0215 local time and awaiting decision by owners on further movement of the aircraft.

https://www.aydinlik.com.tr/_usr/files/img/2018011914362319_pb14v0gpf779ptf33q5p9abut41.jpg

Hotel Tango

19th Jan 2018, 12:51

The damage looks quite extensive. However, the air frame is relatively young. TC-CPF first flight was 30/Nov/12. I'm interested to see if the insurers write it off or go for a repair option.

West Coast

19th Jan 2018, 14:09

From the time lapse video...

Presuming the runway closed for the operation? Odd that the runway lights were illuminated if so.

Intrance

19th Jan 2018, 14:09

Too early is before you exit RVSM levels....RVSM requires only for the equipment to be there, certified and functional, not engaged IIRC :p :ok: .

cats_five

19th Jan 2018, 14:29

lansen

19th Jan 2018, 16:29

Is this the case ? I understood the FO mistakenly pushed the TOGA Pb instead of disengaging the A/T (commom error) and the CP took over quickly but forgot to disengage the A/T.

Pressing either of the TOGA buttons instead of disengaging the autothrottle is certainly not a common mistake in the 737. You either have to be retarded, completely unqualified or maybe have a live seizure to mistake/accidently push the wrong one of those buttons :* .

donotdespisethesnake

19th Jan 2018, 17:00

Port side less damaged, I believe it was towed using nose wheel, left MLG and a mobile platform supporting damaged s/b wing, but that was not captured by the video.

https://cdn1.ntv.com.tr/gorsel/turkiye/trabzon-havalimani-ucuslara-acildi,x-HJ8utMf0KP5FHeaXqraA.jpg (https://cdn1.ntv.com.tr/gorsel/turkiye/trabzon-havalimani-ucuslara-acildi,x-HJ8utMf0KP5FHeaXqraA.jpg?width=620&mode=crop&scale=both&v=20180119043405207&meta=rectangle)

https://cdn1.ntv.com.tr/gorsel/turkiye/trabzon-havalimani-ucuslara-acildi,x-HJ8utMf0KP5FHeaXqraA.jpg

News site with video showing detail of accident damage and recovery operation. http://www.haber7.com/guncel/haber/2528382-trabzon-havalimani-ucuslara-acildi

172_driver

19th Jan 2018, 17:15

RVF750

19th Jan 2018, 17:36

Pressing either of the TOGA buttons instead of disengaging the autothrottle is certainly not a common mistake in the 737. You either have to be retarded, completely unqualified or maybe have a live seizure to mistake/accidently push the wrong one of those buttons :* .

Clearly either you've never flown both a 737 and the myriad of Turboprops that have go around switches where the disconnect buttons are on the 737 or you like insulting people.

I have pressed the wrong one on several occasions, but immediately realised and sorted it. (TOGA instead of disconnect). It happens, not that often but when it does it isn't a problem if the person doing it fixes it.

In this case, I and many others suspect the Captain maybe was not fully in the loop that it had been pressed.

sonicbum

19th Jan 2018, 19:44

Nope, FO wanted to Go Around due lack of required visual ref bye Captain decided to take over and land.. there is a big difference. If you simply disconnect the AP and hold the thrust levers closed against the servos and land deep and hard....the rest is history.

Ok it’s a different story then.

sonicbum

19th Jan 2018, 19:53

Pressing either of the TOGA buttons instead of disengaging the autothrottle is certainly not a common mistake in the 737. You either have to be retarded, completely unqualified or maybe have a live seizure to mistake/accidently push the wrong one of those buttons :* .

Erroneously pushing the toga PB is a commom mistake at cadet level if the hand on the thrust levers is not positioned properly. I have seen it in the Sim a few times with experienced crew as well during turbulent conditions for the same reason stated above. Hand position on the thrust levers is crucial to avoid any inadvertent activation of the push buttons. But lansen don’t worry, You are an astronaut so these discussions are understandably useless for You. If (and it’s a big if) you’re a captain on a 737 and your low hours FO makes this mistake you can always tell him what you wrote in Your post ;-)

framer

19th Jan 2018, 21:51

It happens on a regular basis. The PF is anticipating a go- around, either consciously or sub consciously has finger poised to hit TOGA, gets visual and the cognitive process of switching to a mental model of disconnecting automatics and landing is incomplete. Bingo, TOGA pushed. I have seen it once in ten years so I imagine it happens on a weekly basis globally.

lansen

20th Jan 2018, 07:29

Sonicbum
Calling me an astronaut made my day.

To all of you apparently feeling emotionally attached to wether this is or is not a common mistake. I'm truthfully sorry. I didn't mean to attack anybody's feeling or anything like that. I simply say that I have never seen anybody do this mistake. And well yes, I'm not in training. I however still have a very fair amount of experience on the 737, classic as ng.

RAT 5

20th Jan 2018, 08:40

I have to admit being surprised by this error. I've never seen it, but there were numerous memos to the trainers to insist on correct hand position because of it. I always trained correct hand position, but for proper TL control reasons, not inadvertent TOGA. If your hand is in the correct Boeing position the thumb is over the AT disconnect switch, true, your 1st & 2nd fingers are also hovering over the TOGA switches. i.e. the correct position gives instance access to both without any hand movement. Therefore the brain has to send the signals to the correct digits depending on what you want to happen. Thus I've never understood how the correct hand position prevents wrong selection.
The incorrect hand position I observed frequently, was guys flying with their hands flat on top of the TL's & TR's and squeezing the whole fitment; either pushing the TL's forward with their palms, and sliding them back with fingers on the TR's. Not good. The TOGA switches were hidden under their hands and inaccessible without lifting the complete hand off the TL's and replacing them. The AT disconnect switches were not covered at all.
This technique of controlling TL's on finals with sweaty palms or gusty conditions was very imprecise, inaccurate & not positive control. Their hands were moving up & back to reposition depending on wanting more or less thrust.
I still fail to understand how it could cause erroneous selection of TOGA, but evidently something did. I'm just not sure this was the reason.

Centaurus

20th Jan 2018, 11:02

either consciously or sub consciously has finger poised to hit TOGA

A dangerous habit but common. A more prudent technique is to manually advance the thrust levers towards go-around thrust while pitching up as part of the GA procedure. Once it is evident that the thrust levers are in the high power range, only then press TOGA which in most aircraft will place the FD's in the TOGA mode (if you need them) Depends on the aircraft type.

This reduces the chances of inadvertently selecting an incorrect mode while fiddling with the TOGA buttons while at the same time giving a moderately high enough thrust setting enabling a safe initial climb away gradient.

RAT 5

20th Jan 2018, 12:47

A more prudent technique is to manually advance the thrust levers towards go-around thrust while pitching up as part of the GA procedure.

That would suggest you are the type of long disappearing pilot who likes to control the a/c rather than be a follower: but I don't want to open up that long running never ending debate.

number0009

20th Jan 2018, 16:51

Found a good recovery photo.

https://images.csmonitor.com/csm/2018/01/1054300_2_04_standard.jpg?alias=standard_900x600nc

BraceBrace

20th Jan 2018, 21:39

I have to admit being surprised by this error. I've never seen it, but there were numerous memos to the trainers to insist on correct hand position because of it.

Ever heard of the word "brain fart"? Brain farts are part of aviation, because we pilots get tired after long trips or in the early mornings after night duties.

It surprises me greatly that nobody here mentioned that the safest way is easy: there was no reason for the captain to take over controls, the go-around should have continued even if started accidently. Safest option. Safest solution. Trying to recover from a started go-around is asking for problems, especially on a 737 with a hard power-pitch effect. Go-arounds are non-events, not really what you can say here...

We pilots make mistakes, live with it, stay safe.

Bomber Harris

21st Jan 2018, 00:48

https://www.reddit.com/r/aviation/comments/7rq89h/pegasus_boeing_737800_is_recovered_from_the_slop/?st=JCO4I6MD&sh=7681c348

CurtainTwitcher

21st Jan 2018, 02:11

It surprises me greatly that nobody here mentioned that the safest way is easy: there was no reason for the captain to take over controls, the go-around should have continued even if started accidently. Safest option. Safest solution. Trying to recover from a started go-around is asking for problems, especially on a 737 with a hard power-pitch effect. Go-arounds are non-events, not really what you can say here...

Unfortunately the same lessons are being learnt over and over again. Why the decision to continue to land if this is the cause? Ego, embarrassment, management pressure, QAR, get-home-itus or for a multitude of unknown reasons.

If, and I stress if it turns out to be the case, then it would appear to be quite similar to QF1 in 1999 and the EK DXB 777 accidents.

QF1 was also a case of a "rejected go-around", that in hindsight, I'm sure the LHS if he had his time again would just have let the process of a missed approach to happen just as per procedure. QF1 Accident report. (https://www.atsb.gov.au/media/24447/aair199904538_001.pdf)

I have to admit being surprised by this error [inadvertent TOGA]. I've never seen it, but there were numerous memos to the trainers to insist on correct hand position because of it.

This is the essence of the problem, surprise leading to confusion, leading to error. There is actually very little academic literature about the mental state of confusion. Confusion takes time to resolve, and by the time our brains resolve the confusion, there may be insufficient time to fix the problem.

Close to the ground, confusion is to be avoided at all costs, SOP and only SOP will keep you safe 99.999% of the time. For all those times with a minuscule probability, you just have to make it up & hope your brain can perceive things clearly & quickly enough to resolve the scenario safely. In the case of the EK DXB777, the FO followed SOP to the letter, but failed to notice the mistake of TOGA being pushed after main gear weight-on-wheels thereby that it disabling it.

As I said, there is almost no work done on this state of mind & decision making. It is worth examining your own mental processes at work, to determine just how much of the time that you end up in this state, and how long it takes to resolve. You have to be honest about it to yourself.

The opposite state also occurs, where you are in a state of "flow (https://en.wikipedia.org/wiki/Flow_(psychology))".
In positive psychology, flow, also known as the zone, is the mental state of operation in which a person performing an activity is fully immersed in a feeling of energized focus, full involvement, and enjoyment in the process of the activity. In essence, flow is characterized by complete absorption in what one does, and a resulting loss in one's sense of space and time.

In this state, time is slowed, and everything is clear, and error resolution is much easier. However, as pilots we don't get to chose the timing of our mental states.

Recently in this state of flow, I observed a highly experienced fellow crew member make a MCP error. He was totally confused (arming APP early, capturing GS before LOC capture, then immediately setting missed approach heading resulting in us turning away from the LLZ intercept). I could actually observe his surprise & confusion at what was happening, and his inability to resolve the solution (simply turning the heading back to original intercept). All I had to do was prompt him to set the heading and his confusion was immediately eliminated. In this instance, I could slowly and methodically observe each and every one of his touches of the MCP panel, and actually anticipate the error, and solution with ease.

I felt totally "in-tune" with both the aircraft, and other pilot making the mistake, that is a state of flow. My mental state of flow just happened to coincide with his error in this particular instance. This isn't always the case & I only tell the anecdote as an example of how our minds work sometimes, not self aggrandizement. I'm nothing special when it comes to aviation.

bnt

21st Jan 2018, 09:27

Recovery video:

https://www.youtube.com/watch?v=YuhmN1yeSE4

sonicbum

21st Jan 2018, 10:25

It surprises me greatly that nobody here mentioned that the safest way is easy:

The reason nobody mentioned anything yet is probably due to the fact that we are basing everything on assumptions as there are (obviously) no preliminary reports out yet. What the crew "should have done" in a total lack of event details is totally useless.

gearlever

21st Jan 2018, 11:16

- No preliminary report
- No final report

Never ever, 'cause Turkey doesn't follow ICAO ANNEX 13.

Centaurus

21st Jan 2018, 12:15

I could actually observe his surprise & confusion at what was happening, and his inability to resolve the solution (simply turning the heading back to original intercept).

The solution is easily resolved by following the advice recommended in the Children of the Magenta Line video.

And that is "CLICK CLICK" disengage the autopilot and if appropriate the autothrottle, and without delay manually recover the situation to get back to the desired heading/course/whatever. Whatever actions take place after that depends on pilot discretion.

gearlever

21st Jan 2018, 12:42

Children of the Magenta

should be shown in every training departement.

Many incidents/accidents could have been avoided....

PEI_3721

21st Jan 2018, 14:47

Centaurus, gearlever, I disagree.
It is the ‘click click’ mentality which more often contributes to mistakes.

First just because crews have been shown a film it does not mean that they will change behaviour as required. Why should individual pilots, training, or management think that way; ‘video training complacency’.

Second, ‘click click’ training does not explain when to disengage autos; the critical aspects of judgement based adequate awareness of the situation. Many problems in this category arise from SOPs, - when to use autos or not, and the underlying philosophy of safety benefits. Why use A/T independently from the A/P - few people would consider the opposite arrangement.

Third, is the method of disconnecting fully explained, which includes the means of confirming the selection and appropriate cross checking. How many incidents originate from less than adequate PNF duties when Captains are in that role?

gearlever

21st Jan 2018, 14:53

It's not about a "video", it's about a philosophy.

"If you don't like what you see, or don't understand.. click, click."

This incorporates manual flight = manual thrust.

PEGASUS, as many other accidents may not have happened with "click, click".

Council Van

21st Jan 2018, 15:25

Pressing either of the TOGA buttons instead of disengaging the autothrottle is certainly not a common mistake in the 737. You either have to be retarded, completely unqualified or maybe have a live seizure to mistake/accidently push the wrong one of those buttons :* .
I pushed the auto throttle disconnect button on my first 757 renewal sim when I wanted to go around, but I had flown Dornier 228's for ten years. They did not have auto throttle but to set the flight director for take off or to go around you would press the TOGA button on the side of the throttle in exactly the same position as the auto throttle disconnect switch in the B757.

I guess that makes me retarded as I was qualified and was not having a seizure.

Chesty Morgan

21st Jan 2018, 16:20

fox niner

21st Jan 2018, 19:52

If you click click the autothrottle on every flight, you will not make a mistake so quickly by inadvertently pressing toga instead.
It all boils down to:
1. Are you allowed by sops?
2 are you comfortable to do so because of your training?
3. Are you encouraged to manually fly the beast by the airline/crew mates/culture?

BraceBrace

21st Jan 2018, 21:50

Whatever actions take place after that depends on pilot discretion.

Not really, for anything that creates an "unstable approach" you will have to go-around, a rule implemented by pretty much every sane company. Unstable is from 1000/500 AGL... and below. Children of the magenta is fantastic and tries to solve problems, below a certain height trying to solve problems is not the preferred method, staying safe is.

But I completely 100% agree that as far as this flight is concerned, it is all speculation. I'm only referring to proposed reactions in case of certain failures - in general -.

Tetsuo

28th Jan 2018, 18:08

According to news on Turkish media the plane is a write off.

Pistten ç?kan uça??n ak?beti belli oldu - Cumhuriyet Türkiye Haberleri (http://www.cumhuriyet.com.tr/haber/turkiye/914716/Pistten_cikan_ucagin_akibeti_belli_oldu.html)

gearlever

28th Jan 2018, 20:19

Never ever Turkish Media will tell about a mishap of their "Heroes"...

ExSp33db1rd

28th Jan 2018, 20:41

A more prudent technique is to manually advance the thrust levers towards go-around thrust while pitching up as part of the GA procedure.

Absolutely - what's wrong with that

That would suggest you are the type of long disappearing pilot who likes to control the a/c rather than be a follower:

Yes.

hans brinker

28th Jan 2018, 21:32

The solution is easily resolved by following the advice recommended in the Children of the Magenta Line video.

And that is "CLICK CLICK" disengage the autopilot and if appropriate the autothrottle, and without delay manually recover the situation to get back to the desired heading/course/whatever. Whatever actions take place after that depends on pilot discretion.

ATP(L) for 20 years, 20 years flying, from turboprops without any AP/FD/AT to the (current) A320. I do the T/O without FD/AT on any T/O when possible (non-RNAV SID), I normally go AP/AT off latest passing 10K in the descend and weather/approach permitting FD off as well.

Yes, I have saved a few situations by losing the automation and going back to green needles, but I think in the vast majority of "what is it doing now?" while on automation a more appropriate reaction is:
-first, make sure the right mode is selected
-if that is not it, go back to basic mode (HDG/VS/SPD on the bus)
-if that doesn't work Click Click.

Off course if you find yourself diving to the ground and only have a second to recover it is different. Most of the time if you find yourself in a situation where you are not sure where the AP is going to, and switch everything off, you are making life much harder for your other crew member, who now has to solve the puzzle all by himself while talking to ATC, as you are going to be busy keeping the blue side up to do anything else useful.

Especially on the bus, unless you are already on an ILS switching the AP of doesn't really help much because you still have to follow the FD (there is no CDI in RNAV and nowadays you are not normally on any radial, if you have to follow the FD you are better of having the AP on as well...

Just my opinion.

sonicbum

29th Jan 2018, 08:47

If you click click the autothrottle on every flight, you will not make a mistake so quickly by inadvertently pressing toga instead.

Did not really get what you mean here. You must click click the autothrottle on every flight before landing anyway unless you carry out an autoland.

tractorpuller

29th Jan 2018, 13:08

That “must“ would be company specific,as lots of airlines permit a manual landing with AT on.

J.O.

29th Jan 2018, 13:13

Airbus permits manual landings with auththrust on, but not on the 737/757/767.

sonicbum

29th Jan 2018, 19:39

tractorpuller

The “must” is Boeing specific.

tractorpuller

30th Jan 2018, 00:55

Weird. I fly a Boeing and we do manual landings with AT all the time.

J.O.

30th Jan 2018, 04:46

Weird. I fly a Boeing and we do manual landings with AT all the time.

Which type?

sonicbum

30th Jan 2018, 06:28

Isn’t this thread about a Pegasus 737 or am I missing something.

RAT 5

30th Jan 2018, 07:57

The authorities have all the players at their disposal, including the a/c. How can they not have discovered what happened by now? All this bar-room speculation yet some one must have all the facts. Where are they?

Skyjob

30th Jan 2018, 08:29

In Turkey...

gearlever

30th Jan 2018, 12:06

States in charge of an investigation must submit a Preliminary Report to ICAO within thirty days of the date of the accident, unless the Accident/Incident Data Report has been sent by that time. Preliminary
Reports may be marked as confidential or remain public at the investigating State’s discretion.

Accident happened JAN 13th, so wait...

Nevertheless Turkey doesn't publish Aviation accident/incident reports.

RAT 5

30th Jan 2018, 12:06

Yeah, but where are Boeing in this? They should have been involved, surely.

J.O.

30th Jan 2018, 15:23

They know which side of their toast is buttered and they're not about to walk over a country - and its airlines - who've put plenty of bread on their table.

gearlever

30th Jan 2018, 18:28

YEP. You nailed it.

tdracer

30th Jan 2018, 19:17

They know which side of their toast is buttered and they're not about to walk over a country - and its airlines - who've put plenty of bread on their table.
While that certainly plays a part, it's more basic than that. The aircraft manufacturer is a participant in the investigation, but all information releases must come from the government agency responsible for the investigation. During my career I was involved in a couple accident and several incident investigations - and violating the investigation confidentiality was a good way to get severely reprimanded or even fired. I wasn't even supposed to talk about it with co-workers that weren't involved in the investigation or didn't have a 'need to know'.

I suppose if the investigating agency released something that blamed the manufacturer, and that the manufacturer felt was false or seriously misleading, the manufacturer could release some sort of rebuttal, but it would be carefully worded and blessed by a team of lawyers before it saw the light of day.