Non counteracting aileron

[LetsFlyAway]

I flew into EGBB this morning and while the E195 taxied to the gate I noticed an aircraft that had its left aileron in a down position with the right aileron in a neutral position.

Is this possible? I thought the ailerons counteracted each other so if one goes down the other goes up?

Thanks for any insight!

[TurboTomato]

Was the other aircraft moving or stopped at the time?

[LetsFlyAway]

Stopped at the gate with APU and beacon on.

[gas path]

Aircraft type? Modern a/c like the 777 and airbus types with fly by wire flight controls, one or both ailerons (or elevators) will sink under their own weight. Also powering up just one hydraulic system will be enough to 'fair' a drooped flt.control.:8

[LetsFlyAway]

Was an Aer Lingus think it was an A320.

[LetsFlyAway]

thanks for the insight also : )

[HEATHROW DIRECTOR]

Same used to happen with DC-9 elevators - one up, one down when parked.