One for the fly boys

IanAnderson · May 21, 2011

Amazing footage shows out-of-control plane - Yahoo! News

brianstewart · May 21, 2011

I would not have enjoyed being on board that...

David Morton · May 21, 2011

I think it was discussed on PPrune extensively and one of the suggested
problems was a device called the Yaw Damper. How the russians designers configure their flying controls is beyond me, and so it seems is beyond them as well , but the fact remains that swept wing aeroplanes such as this rely heavily on devices such as these Yaw Dampers. They are often set up with different rates of control regime depending on altitude and speed at the time. Other flying control surfaces that do this as well are the elevators and in fact the Nimrod had a physical changeover to course from fine descending through approximately 10,000ft. The 747 .400 has inboard and outboard ailerons, the outboards have a much greater lever moment and therefore a much greater effect and the switch over is 232kts, below which they all work and above which only the inboards work. It also has variable horizontal stabiliser (tailplane)trim which is so important it's duplicated in case of a failure. Do they fail ? Yes indeed. Yes - I had no outboard ailerons and both channels on the stab trim failed on approach into LHR. It was very slow, but not difficult, to turn. People often say what is wrong with using the rudder to turn. Its such a big machine and the rudder is big as well and very effective so it twists the fuselage. The rudder is for engine failures and not a lot else. Sensing the speeds and altitude uses a device called a heated Q pot so it may have been a simple failure of something like the heater in the Q pot which nearly cost the lives on this aeroplane.
Of course , we will never know as the Russians are never very forthcoming about accidents within their own territorial boundaries. It detracts from the fact that these aeroplanes are supposedly made by supposedly the best engineers in the world from the glorious soviet socialist republic and destroys their dream like self belief. Oh yes - in the 60's until well after Gorbys glasnost, overseas flights always carry a party member to stop the crews defecting.

Keith1 · May 21, 2011

Ah! The Cropduster Method....

toy264 · May 21, 2011

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oNotPromoteQF/> <w:LidThemeOther>EN-US</w:LidThemeOther> <w:LidThemeAsian>X-NONE</w:LidThemeAsian> <w:LidThemeComplexScript>X-NONE</w:LidThemeComplexScript> <w:Compatibility> <w:BreakWrappedTables/> <w:SnapToGridInCell/> <w:WrapTextWithPunct/> <w:UseAsianBreakRules/> <w

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ontVertAlignInTxbx/> <w:Word11KerningPairs/> <w:CachedColBalance/> </w:Compatibility> <w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel> <m:mathPr> <m:mathFont m:val="Cambria Math"/> <m:brkBin m:val="before"/> <m:brkBinSub m:val="--"/> <m:smallFrac m:val="off"/> <m:dispDef/> <m:lMargin m:val="0"/> <m:rMargin m:val="0"/> <m:defJc m:val="centerGroup"/> <m:wrapIndent m:val="1440"/> <m:intLim m:val="subSup"/> <m:naryLim m:val="undOvr"/> </m:mathPr></w:WordDocument> </xml><![endif]-->It looks like a case of inertial coupling, verging on departure. In the video at a couple of points you can see the pilot pitching the nose down 15 or 20 degrees to unload the aircraft, which is a classic recovery technique. Loss of the yaw damper might explain it.

David Morton · May 22, 2011

John,
Insufficent speed for IC ?

One for the fly boys

Ian Anderson

Brian Stewart

David Morton

Keith

John Fitzpatrick

David Morton

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