Cant be...a real show of what not to do in all aspects of PF/PNF demonstrated by both pilots,especially the guy in the left.
It hurts the eyes for sure.

Not me. You mixed me with somebody. At least not about MH17.

About this Kommersant' article (and it's direct translation on RT with only their own addition about steering separation) it for me looks not more believable than that "knuppel" business.

MAK issued press-release concerning this latest "investigation results". In short it can be translated into "who are all this people and what are they talking about?".

It seems to me that according to the previously-posted article prepared by Boeing http://www.boeing.com/commercial/aer...ERO_2014q3.pdf shows several ways to crash the airplane without any mechanical/technical problem at all! I could be full of it, since I'm not a pilot.

The link is broken.

So sorry, yes it is. It may have been removed. Checking.

http://www.boeing.com/commercial/aer...ERO_2014q3.pdf

pp13-17: Performing Safe Go-Around Maneuvers

Correct link to Boeing Article
 

OK, this one works, at least for me:
http://www.boeing.com/commercial/aer...ERO_2014q3.pdf

I hope that every pilot who's flying passengers is thoroughly familiar with this information. Some of the responses here convince me that not everyone is familiar with this information. The article is on Page 13.

From MAK/IAC (Artur Muradyan, aide to chairman):

"At this time, we can neither confirm nor deny the reports of the pilots' last conversation. Neither MAK nor any of its employees gave any information to the media - not to Kommersant, not to anyone at all. When we release our data, it will be open to comment. We haven't yet completed the decoding of CVR and FDR, it's in progress, we're still analysing and compiling the data and identifying the [pilots'] voices. It's possible that we will release some preliminary data in a couple of weeks, but the final results of decoding will be published in a month."

Talking about a fully mechanically controlled airplane this makes no sense at all. There's a direct mechanical connection between the flight controls and the control surfaces (normally hydraulic, but manual fallback) in the 737. There are no "conflicting commands".

And while a "split elevator" condition arising from both pilots pushing/pulling on the yokes against each other may occur in the 767 (see the final report for Egypt Air Flight 990), I have never heard of this for the 737, and that alone would not automatically cause loss of control and crash, much less a stall.


Bernd


EDIT: Egypt Air 990 was a 767. Thanks, Airbubba.

Makes a lot of sense.
In a "mechanically" controlled 737 (as you said it) dual input is very much possible. I suggest you update your knowledge - it is possible in ANY Boeing. If actions of both pilots are sufficiently different and forces exceed some limits - both sides will be separated, this was done to counter possible jamming of controls on one side, certification required such a solution.

The controls are not "normally hydraulic, but manual fallback" - the pitch controls and ailerons are cable and pulley systems, with hydraulic assistance. Manual reversion simply means the hydraulic (or electrical for stab trim) assistance is removed. The controls can split between the two columns, the captains column connected to left elevator and ailerons, the fo's connected to right elevator and spoilers. They split in case one jams, as Olasek said.

Amazing how many people are commenting here without proper knowledge.

Ever tried that in the sim? The system simply does not work, and so nobody has ever tried it to see what happens ( I have asked many times, with no success).

Come on chaps - how many have done a control disconnect in the sim? Looks like another 737 system that does not work.

Yes, once, a long time ago (Classic, but the system is the same as the NG). The breakout force is fairly large, but it works.

SLF. Would a 'split' elevator explain the roll/ bank?

Seems like a common thread to quite a few accidents in the last few years is inattention to the correct pitch attitudes. (Think of the initial autopilot disconnect on AF447). In the older types the flight director was a fairly crude device with limited modes so it was taken for granted that you needed to know the raw data attitudes for a given phase of flight and also to monitor carefully that these were being flown correctly.

I know how it actually works (hydraulically augmented cable-and-pulley), but that's not how Boeing describes it in the (admittedly not necessarily technically precise) FCOM:
So I chose to go with Boeing's description, knowing that it is slightly misleading.

And what I mean is that it makes not sense to say any single entity receives "conflicting commands", since after a split there is no longer a single system, but rather two separate ones (if that is indeed the case; see below). And an airplane as such cannot receivce "conflicting" "commands", it just experiences forces and moments and reacts according to the laws of physics.

I know (and mentioned in my previous post) that what you say is true in the 767 (as evidenced by Egypt Air 990), but the description in the manual does not imply this specifically for the 737.

In fact it says that both elevators are linked by a torque tube, which is mentioned separately from the so-called "override mechanism", which allows the two control columns to be separated in the event that one of them becomes jammed. This does not really imply that it is the torque tube which is broken to free a jammed control column, but rather the connection between the two control columns.

Instead of bemoaning people's lack of knowledge you could just respond to my wondering if the 737 systems are indeed supposed to work the same as in the 767.

If my understanding of 737 is demonstrably wrong, please correct me by citing authoritative sources (which I agree the FCOM is not for a technical description; but it often gives a good idea.)


Bernd


EDIT: Egypt Air 990 was a 767, Thanks to Airbubba for the correction.

Probably not to the extent postulated in that short amount of time. If unchecked it would eventually but the elevators have a very small moment arm.

there's no individual left/right elevator split

......also of interest and applicable to the NG, but not the 300-500 Efis

Thank you. That was my reading as well.


Bernd