Aircraft Crash in Moscow

[Kulverstukas]

Leak from CVR/FDR confirmed that that there was no autospoilers and no reverse unlock signal but levers was moved forward to nominal thrust. Panic in the cabin ("brake! apply brakes!"). Adding landing speed of 260 kmh and 800 m further touchdown...

[BOAC]

Kulver - I would appreciate any contact you have with 204 drivers to explain the reverse controls please. I had assumed it was similar to Boeing in that once the reversers were unlocked by an initial movement of the reverse levers these levers were raised to increase N1, yet your 'leak' says that the ?thrust? levers were moved forward to 'nominal thrust' This should not be possible on the Boeing system since the forward thrust selection via the thrust levers is inhibited mechanically when reversers are unlocked. In normal ops, no pilot would attempt to advance the thrust levers if using reverse, even if they had not unlocked - unless trying for an aborted landing.

[Kulverstukas]

BOAC, it still unclear for everybody including 204 pilots and tech on both russian forums I read. There is mechanical lock on both levers and reverse deployment gears and tech people swear that link between levers and engine is mechanical. But it still seems that there may be conditions when if reverse levers are still locked by no wow signal, wrong manipulations with levers can send engine(s) to N thrust.

This is picture from Service Manual of ПС-90А engine

Pos. 13 is guide which move reverse flaps (as I understand it) and blocks max thrust deployment in intermediate position.

[BOAC]

Originally Posted by Kulver

But it still seems that there may be conditions when if reverse levers are still locked by no wow signal, wrong manipulations with levers can send engine(s) to N thrust.

- thanks again for your help here. If this is in fact true then surely there would be some warning to crews, an ADD or whatever?

[Kulverstukas]

As I belive, this is what all latest bulletins was about - if no indication of REVERSE UNLOCK in green, crew must immediately move levers to idle.

[BOAC]

Yes, I recall you posting that but cannot at the moment remember when it was issued?

[Machinbird]

Kulverstukas
Do you know if there is a flight idle minimum rpm and a different ground idle minimum rpm?

[Kulverstukas]

Bulletin on WOW switches greasing - 24/12/12, amendment to FCOM about reverse - 31/12/12.

[BOAC]

Thanks - so the handling advice only came after the accident. That is a little surprising since I remember you posting a story of another 204 over-run where the engines were thought to have gone to forward 86% N1 with reverse selected. I would have expected some technical investigation and a handling warning well before 29/12. If this turns out to be the same, even more of a tragedy for the victims and families.

[liider]

The overrun with forward 86% N1 with reverse selected happened on 20/12, nine days before the Moscow crash. So the handling warning couldn't be issued "well before". Anyway, it's more about the attitude in Russia - until someone crashes, no one would seriously think about possible consequences.

[HDP]

Overhaed bins falling open on touchdown. Not a very good safety impression.

I flew on a Vladivostok Air Tu-204 last year, and the overhead bins fell open on touchdown. The cabin crew didn't appear in any rush to fix it and it almost seemed like a normal occurrence. I guess the latches aren't very secure.

My video shows almost exactly the same "second bang" as in the Red Wings video. I didn't capture the overhead bins in the video as the passengers next to me started glaring at me and I didn't want to get into trouble, so I continued to shoot out of the window.

I felt safer flying the Tu-154M than the Tu-204 - I had a splitting headache the entire flight as the air filtration seemed to be playing up, and the aircraft kept "swaying" side to side in the cruise, almost as if it couldn't keep the wings level. I'm avoiding the Tu-204 if possible in future, but I'd still fly it if there was no choice - I still consider it safe. Just not the most pleasant aircraft to be a passenger on.

Link

[Capn Bloggs]

Overhaed bins falling open on touchdown. Not a very good safety impression.

Don't look like overhead bins to me; more like the PSUs (pax service units eg O2 masks, call buttons) unlatching. Still not a very good safety impression though.

[Kulverstukas]

BOAC, liider:

I told this already and will repeat, 204/214 flying almost for 20 years now, more than half of ~70 produced still in the air and only one airline suffer from 3 (!) consequential incidents with wow switch and reverse malfunction.

[Count Niemantznarr]

Anyone reminded of the ETIHAD A340-600 "crash"?

Another aircraft with just a crew on it. Seems to be much safer flying with passengers?

Boeing confirms ZA001 factory gauntlet underway (Update1) - FlightBlogger - Aviation News, Commentary and Analysis

Violation of test procedures led to Toulouse A340-600 crash

[Lyman]

Perpignan...

I still say the time to be extra careful is just out of maintenance not just going in

[lomapaseo]

Update on Engine Pics

I did some more comparisons between both engine pics post accident see pic



I had originally assumed wide chord fan blades (low count density) but now realize there are a lot more blades.

Probably low RPM

[Tiennetti]

Loma, wich is the source of the left engine photo?

[Lyman]

This is an overrun excursion into obstacles. As such, a dependence on one possible theory of engine damage needs to be doubted. The aircraft was roughly following terrain in its final 200 meters, terrain that resembles a curve roughly, and may have allowed degenerative velocities around the nacelles.

It is possible the forward third of the aircraft lost its energy whilst uplifting the following structures, wings, and tail. This would allow a form of 'protection' for the casings, and Fans.

The spinners and wide chord blades appear not to have suffered from forward (blunt) impact, and the standard "the blades suggest making power at impact" may not apply here. The corollary "idling at impact" is also suspect.....

The data will show the power levels at 0 velocity. But, just because rhe fans are reasonably void of thrust telltales does not mean the engines were not powered up.

Commanded thrust, delivered thrust, and thrust at impact tell a story, but in the company of the recorders, conjecture from site photography might take a back seat to data.....

[Ds3]

Those pictures look to me like they are of the same engine, the first one after the fire has been dowsed and the second prior to this happening.

The are taken from slightly different angles, but there are number of almost identical pieces of debris in front of the engine and the angle at which they are resting is the same.

[Kulverstukas]

At airliners.net there is a lot of cabin photo of 64047