B-738 Crash in Russia Rostov-on-Don

[Centaurus]

I cannot fathom any current B738 driver sitting with his thumb on the pickle switch for that length of time

I have seen this happen in the simulator on a few occasions. Always during a go-around where the natural pitch up on application of GA thrust is not contained immediately. Usually this happens in IMC where no visible horizon is available to see not only the rate of pitch up but how much above the horizon. In other words poor instrument scan.

Instead of using immediate strong elevator force coupled with careful forward blips to the stab trim to contain the pitch up, the pilot uses the stabiliser trim switch in a continuous motion and keeps his thumb on the switch waiting for a reaction. 12 seconds is a long time to wait for the nose to lower and by then it goes nose down rapidly and no hope of recovery at low altitude on instruments.

It all boils down to poor instrument flying manual skills. Blame lack of proper simulator training in the manoeuvre in terms of manual go-around procedures. Auto go-arounds are a non-event. Manual go-arounds are another story altogether especially on instruments

[framer]

Well if you're so stuffed that your brain is not coping with the info it is presented with, who says it won't 'stall' for twelve seconds?

[henra]

Originally Posted by Centaurus

Instead of using immediate strong elevator force coupled with careful forward blips to the stab trim to contain the pitch up, the pilot uses the stabiliser trim switch in a continuous motion and keeps his thumb on the switch waiting for a reaction. 12 seconds is a long time to wait for the nose to lower and by then it goes nose down rapidly and no hope of recovery at low altitude on instruments.

From all we know this description seems to hit the nail on the head.
Unfortunately the pure readings from CVR/FDR will not be able to finally and undoubtedly confirm this 'why'. It should at least hopefully be able to distinguish if it was an uncommanded trim runaway or a commanded action. If it was the latter, your description is probably as good as it gets.

[JammedStab]

Originally Posted by captplaystation

QDM360, yes sorry, I had read that, but was expecting some more info as to the whys & hows they thought the stab trim would run for 12 seconds (having sat & timed it, I cannot fathom any current B738 driver sitting with his thumb on the pickle switch for that length of time) & was hoping maybe an update with more CVR/FDR input.

You already told us. It is Uncle Sam covering it up. Now, if you want some well thought out reasoning, read again this quote from a few later posts:

"I have seen this happen in the simulator on a few occasions. Always during a go-around where the natural pitch up on application of GA thrust is not contained immediately. Usually this happens in IMC where no visible horizon is available to see not only the rate of pitch up but how much above the horizon. In other words poor instrument scan.

Instead of using immediate strong elevator force coupled with careful forward blips to the stab trim to contain the pitch up, the pilot uses the stabiliser trim switch in a continuous motion and keeps his thumb on the switch waiting for a reaction. 12 seconds is a long time to wait for the nose to lower and by then it goes nose down rapidly and no hope of recovery at low altitude on instruments.

It all boils down to poor instrument flying manual skills. Blame lack of proper simulator training in the manoeuvre in terms of manual go-around procedures. Auto go-arounds are a non-event. Manual go-arounds are another story altogether especially on instruments"

Seems more logical, wouldn't you think.

[sansmoteur]

Very plausible, Centaurus.

[Chronus]

Adding my vote to Centaurus leaves only the following questions. Why the change of mind from going up to going back down or levelling. It has been said turbulence may have been the cause. How severe could it have been, as bad as eye ball shaking - white knuckle grip- thumb frozen on pickle switch type?

[AtomKraft]

I've got 12500 hours in regional ops.

Never flown less than these days,

I often think, as I walk out to the plane, 'am I actually a pilot?'

A I going to fly this thing?

My manual flying skills- which I think are of a decent order, and which I try my best to maintain, seem to be a small part of the skillset needed.......

More prominent things- things featuring in many thoughts before flying skills are.....

1. How am I with the management? Do they think I'm ok? Or are those HR people going to get me?
2. How am I with rostering? God, If only I could get the flights and roster that I want.
3. Will my girlfriend be ok with me going away for five days....?

Bloody hell. Flying the plane is the least of my worries...

[klunk49]

I agree with Centaurus, push in to much thrust, pitch up, get wind gust adding to light weight,you are climbing for a high altitude set in MCP,forget to delete altitude restriction in FMS, FD suddenly says pitch down NOW! Snatch the thrust levers off, pickle trim down, in attempt to return to FMS altitude, trim motor moves HS quickly in flaps 15 position,not looking through FD,tired, brain fart! Went from +20 to -15 pitch, now with HS pitch in -4 degree nose down position, try to recover by only pulling on elevator, won't work. Swiss cheese model accident compounded by tired crew. Lots of "should have,could have, would have" in this accident, lets all learn something from it. The airplane was just along for the ride, nothing wrong with it....Well said AtomKraft!

[Flying Clog]

Bloody hell, that's scary klunk49

[RAT 5]

you are climbing for a high altitude set in MCP,forget to delete altitude restriction in FMS, FD suddenly says pitch down NOW!

Will that happen in TOGA? Is it not the case that MCP ALT controls in TOGA & LVL CHG and FMC ALT controls in VNAV?

[16024]

Is it not the case that MCP ALT controls in TOGA & LVL CHG and FMC ALT controls in VNAV?

Yes.
But only if the MCP ALT is above the point where you engage TOGA. If you forget to set the GA ALT in the MCP (having maybe set a lower MCP ALT to avoid ALT ACQ) it will climb till it runs out of petrol.
If at some point you realise and hit LVL CHG (especially if the MCP speed is high) it will hurry towards the ground.

[Chesty Morgan]

No, it'll head towards whatever altitude you have set when you press TOGA. It won't automatically climb!

[de facto]

click click,,magic

[16024]

It won't automatically climb!

It won't "automatically" climb unless you are dual channel and Flare Arm. But provided TOGA is armed (and there's no way of telling) you'll get 15 degrees pitch UP, and if the A/T is in you'll get a handful of thrust.
Surely (Shirley?) you're not saying if I am at 2100 feet on the Glide with 2000 M/A set its going to go down in TOGA.

[Centaurus]

Bloody hell, that's scary klunk49

So is blindly following a flight director into the deck

[RAT 5]

True; I was forgetting they initiated TOGA quite early, i.e. well above MDA. However, they had briefed and requested FL80, and the PF had asked on approach if the MCP had been set. It would have been either 3000' or 8000. Either way above the TOGA altitude???

So is blindly following a flight director into the deck

I have seen in the sim, cadets under stress as they all are, on an ILS at DA the application of GA power without pressing TOGA and continue down the GP at accelerating speed. FLT FRZ and discuss. Both for PM & PF.

[Chesty Morgan]

Originally Posted by 16024

It won't "automatically" climb unless you are dual channel and Flare Arm. But provided TOGA is armed (and there's no way of telling) you'll get 15 degrees pitch UP, and if the A/T is in you'll get a handful of thrust.
Surely (Shirley?) you're not saying if I am at 2100 feet on the Glide with 2000 M/A set its going to go down in TOGA.

No, my bad, I didn't read your post properly (blame a Borolo induced hangover). GAs at heights above TOGA activation have seen recent discussion at our place and the importance of setting the MAA first if you're using Level Change. We've got a handful of aircraft where TOGA activates above 2000' but most don't.

[16024]

We've got a handful of aircraft where TOGA activates above 2000' but most don't.

Yep, the 737 options list must be like a phone book.
"It's like a box of chocolates..."

[RAT 5]

Except with such a box of chocolates I often close my eyes to be surprised. You don't know what you're getting. NOT recommended on an a/c.

[FGD135]

I cannot fathom any current B738 driver sitting with his thumb on the pickle switch for that length of time

Very easy to fathom.

The pilot presses the switch, and leaves it pressed, knowing that he is going to have to leave it pressed for a good 5 seconds or so.

But, approaching the 5 second mark, he gets distracted. This was about the time the aircraft was levelled off, so the need to manage the flight path would have provided several challenges that would easily be enough to distract a tired pilot.

Was there a radio exchange at around this time? If so, that could also have served as the distraction.

Being distracted, his thumb just remains on the switch ...

I bet Boeing will modify the trim logic so that the trim can only be run for a maximum of a few seconds at a time.