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Serious UTair Boeing 737 Upset Involved Excessive Pitch And Roll

Russian investigators have detailed a serious loss-of-control incident last month involving a Utair Boeing 737-500 on approach to Moscow Vnukovo. ( 更多...

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The notation in the article about the auto throttle NOT having been turned off may prove to be a contributing factor. The article does note that the auto PILOT was off.
There seems to be a contradiction in the article.

One paragraph states, "As the 737 approached the entry point to the glidepath, at around 130kt, the crew extended the flap setting to 30° and the autopilot disengaged."

Two paragraphs later, it reads, "The pilot's control column, it states, was pushed nose-down and the thrust levers were pulled back to a lower power setting, but without a disconnection of the autothrottle."

I don't get it.
joel wiley 1
?? Autopilot NE autothrust ??
Got it. I'm tired and missed that. Thanks for pointing it out.
ekim125 2
Everyone involved very fortunate there were cool capable hands on the controls. Vodka for everyone. I hope the maintenance guys deserve the spirits.
Bill Garcia 2
Something doesn't compute here. This is on final approach?! Let me get the attitude straight in my head: 45 degrees pitch, 96 degrees bank (so it's past knife-edge!), speed under 135 knots, altitude less than 2,000 feet. This aircraft is not recoverable, something must be lost in the translation or I'm grossly misunderstanding this article.
pagheca 2
it's incredible that at a 96° bank angle no PAX was hurted by objects falling from the overhead bins or kept on their laps.
ko25701 1
G-force really works
pagheca 2
please, let me understand: doesn't a 95° bank angle means that the aircraft was more than vertical?

Pretty scaring for the passengers and the crew!!
toolguy105 1
That is correct. Usually once a plane passes 90 degrees of bank it is unrecoverable. This is where luck and skill combined to save that plane.
pagheca 1
thanks. I have now seen the movie from the FDR. Amazing recovery...
High bank angles are not in and of themselves unrecoverable. Pilots are being trained to recover from extreme attitudes. Look up UPRT.
Serious indeed and the crew did well to recover from the gross upset.They didn't mention why the autopilot disconnected.
That has yet to been seen (the crew doing well). It's also possible pilot incompetence to get into the situation in the first place. We don't know what the autopilot mode was prior to disconnect, we don't know if the pilots disconnected it or if it happened automatically, we don't know what the Flight Management Modes were which are all key parts of the puzzle...
Sure thing. The report on ASN is more understandable
bbabis 2
Wow! That does not look very good for the crew. The plane finally saved itself by doing what a well designed plane should do at the stall. Crew was along for the ride instead of commanding. Luck indeed saved the flight.
I just watched the video--it put a knot in my stomach! Amazing how it recovered.

At what point in the severe positive nose attitude/low airspeed situation that this plane got into does the vertical stabilizer effectively cease to control yaw due to blockage of air flow by the fuselage?
96 deg. bank, 65 KIAS, isnt this an incipient inverted flat spin ? Recovering at 1000 feet agl. Some flying, 99 times out of 100 this had to be unrecoverable in a 735 ! Has anyone got some free simulator time ?
is 100 kts not stall speed?
hence rolling over .
Yup, one wing stalled.
The book stall speed assumes 1g flight. You can be at 0 kts and 0 gs and not be stalled. Of course it's extremely difficult to set up this scenario, but I have been at 30 kts or less at very close to 0 gs in a T37 and not been stalled.
Could someone have hacked into and taken over the plane?
The article states the auto pilot disconnected. We don't know why but it does sometimes just happen. Whatever the reason, once it's off, the 737 is a totally manual aircraft, whatever happened after that was likely due to pilot input. Having said that, until we see the data from the flight data recorder (FDR) we don't know if the pitch up was 'commanded' by the pilots or not. There was an issue decades ago alluded to elsewhere of an uncommanded opposite rudder movement in earlier versions of the 737 (having to due with the yaw damper system which is not applicable to the elevators) but I have never heard of a such a thing happening in pitch.
sparkie624 0
I would say no... That would be an impossibility and if that had happened there would have been more on the FDR!
They did have to clean a number of seats, I imagine.
wafa rizk 1
Note USAirways 427, over Pittsburgh there was an issue with fligh augmentation hydraulics valves supposedly was remidied
joel wiley 1
sparkie624 1
Interesting... .Does not sound like weather... Will be interesting to see what they find out...
bbabis 3
Agreed. I hope the official finding makes its way to FA. For now I think luck played the biggest role in the safe termination of this flight.
toolguy105 1
Luck may be a part of it but good piloting skills and the ability of stick and rudder flying had a lot to do with it. Had this happen in an Airbus Joystick contol piloting I don't think the out come would be the same. The computer save the plane instructions would be overriding the pilots input.
Tony Perez 1
Also with Boeing aircraft, the autopilot physically moves the flight controls so pilots can see what it's doing and grab control if they need to. With Airbus, the flight controls don't move; the autopilot interacts with the plane behind the scenes.
sparkie624 2
That was one contributing factor to the Air France pancaking into the ocean... the FO was pulling the stick all the way back and no one else knew it.... If the opposite stick had moved the 2nd crew member may have been able to save the plane... I think that is one of the Biggest issues that I have with Air Bus...
toolguy105 0
This has happened three times before two of the time the pilots did not regain control and the aircraft crashed. The problem at that time was traced to a hydraulic actuator for the rudder. Boeing spent millions retro fitting all the 737's in operation and new 737 were fitted with the new actuators.

Russians investigators have not given any other information as to the age of the plane, the model or when the last heavy maintenance was. Speculation; is it possible the rudder actuator was during the last heavy maintenance and the wrong one installed?
Are you referring to these? (from Wikipedia) The NTSB concluded that similar rudder problems had caused the previously mysterious March 3, 1991 crash of United Airlines Flight 585 and the June 9, 1996 incident involving Eastwind Airlines Flight 517, both Boeing 737s.

This is not likely the cause of this incident though.
sparkie624 3
I do not think this was a rudder actuator issue... In all of those cases it put the plane on it's back and out of control... Also that vintage of a/c here in question has the newer actuator. The old ones were long gone before this a/c was even manufactured.


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