PPRuNe Forums - View Single Post - Air Asia Indonesia Lost Contact from Surabaya to Singapore
Old 5th Dec 2015, 19:33
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FDMII
 
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EMIT, "All the captain had to do, was push the override button to get full control."

Yes. The last pilot to push the button retains control while the button is pressed.

Further detail from an AOM:

A pilot can deactivate the other stick and take full control by pressing and keeping pressed his priority takeover pushbutton.

For latching the priority condition, it is recommended to press the takeover push button for more than 40 seconds. This allows the pilot to release his takeover push button without losing priority.

However, a pilot can at any time reactivate a deactivated stick by momentarily pressing the takeover push button on either stick. If both pilots press their takeover pushbuttons, the pilot that presses last gets priority.
_Phoenix;
True, BUT elevator is not a direct function of sidestick position.
Yes, I know. I said this in my response to you.
Even with full nose-down pitch command, as the airspeed built up in the recovery the nose-up trim had too much influence to overcome and the airplane would pitch up despite any action on the sidestick.
Well, I don't think that claim can be made without the aerodynamic work behind it support the claim. The elevator in AF447 remained effective and could have brought the nose down.
Something fundamental has to change on this matter, for a simple reason: under stall it's imperative to reduce the AOA, if PF demands nose down rotation then A/C should start rotate that direction not opposite. How? engineers to figure out: THS position, moving fuel foward, etc
Regarding something fundamental having to change, no, I wouldn't think so, not, at least, until the assumption the statement is based upon is well understood and supported as per the above.

Regarding using the THS wheels on the center pedestal, the THS is always available mechanically. Moving it ND would have improved chances for recovery in both this, and the AF447 cases.

Regarding the moving of fuel forward, the notion is entirely impractical for the A330/A340 due the time it takes to do so, (20 minutes, roughly from full to empty), and technically not possible in the A320 as there is no fuel stored in the horizontal stabilizer and moving fuel in the wing-tanks inboard takes more time than any meaningful improvement to CG could be accomplished.

Last edited by FDMII; 5th Dec 2015 at 19:52.
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