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Teevee
3rd Sep 2015, 15:25
I have just been watching a video of the AN124 landing at Doncaster three days ago. It is on another forum so I am not sure I could link to it. The aircraft lands, the spoilers deploy and quite clearly the aircraft pitches up and the nose gear lifts off the runway. Does this happen often? I put a question on that forum and the guy who filmed it says that he has filmed many 124 landings but never seen it happen before!

737aviator
3rd Sep 2015, 18:38
While not Russian enough, spoiler deployment on the 737 causes a pitch up moment anyway! ;)

Chesty Morgan
3rd Sep 2015, 19:35
As the lift is lost towards the rear of the wing the centre of pressure will move forward creating a larger nose up moment.

Teevee
3rd Sep 2015, 19:39
Thanks. It just surprised me that it was enough to lift the nose gear three or four feet up into the air. I guess it happens once in a while!

Intruder
3rd Sep 2015, 21:23
If outboard spoilers deploy but inboard spoilers fail, the center of lift will shift significantly forward and inboard. That will lift the nose to the extent that it could cause a tail strike in some aircraft (e.g., 747) if not controlled properly.

unusualAtitude
3rd Sep 2015, 22:05
Nose gear lifting on spoiler deployment

https://www.youtube.com/watch?v=DmjzRd-lkfk

AerocatS2A
4th Sep 2015, 00:31
Nose gear lifting on spoiler deployment

https://www.youtube.com/watch?v=DmjzRd-lkfk

A lot of up elevator when the nose gear comes up too. Don't know that it is caused by the spoilers.

tom775257
4th Sep 2015, 10:43
A321 also... if you land at a fairly high nose attitude, the spoilers cause a fairly rapid nose up, so you have to push the stick forward to start with once the mains touch, then pull back as the nose comes down to cushion the nose gear landing. If you land at a lower nose attitude it doesn't seem to be very noticeable.

John Farley
5th Sep 2015, 18:28
Chaps
Spoilers are used to spoil lift and keep the thing firmly on the ground the better to use wheel brakes.
Whether the pilot decides to raise the nose after touchdown in order to use aerodynamic braking and so save on tyres and brakes is a separate issue and depends on several factors.
I don't think anyone should feel that spoilers will cause the nose to rise - in effect out of the control of the pilot.

Intruder
6th Sep 2015, 00:24
"Anyone" would think differently after a #4 Hydraulic failure on a 747! From the QRH:System 4 is inoperative:
Extend the ground spoilers manually and slowly. Automatic extension of the outboard ground spoilers, without automatic extension of the inboard ground spoilers, causes the nose to pitch up.
In the simulator the pitch-up is dramatic, and will cause a tail strike if not handled quickly.

John Farley
6th Sep 2015, 08:51
Intruder

Point taken. I did not word that very well.

I should have missed out "- in effect"

JF