Date: 201411
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: VMC
Aircraft: B757-200
Operator: Air Carrier
Operating under: Part 121
Mission: Passenger
Flight phase: Taxi
ATC / advisory: Ground ZZZ
Aircraft component: Aileron
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; First Officer
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Other / Unknown
Second reporter function: Captain; Pilot Flying
Anomaly: Aircraft Equipment Problem Less Severe
Detector: Person Flight Crew
When detected: Taxi
Result: Aircraft Aircraft Damaged; Flight Crew Returned To Gate; General Flight Cancelled / Delayed; General Maintenance Action
Contributing factors: Aircraft; Human Factors; Procedure
Primary problem: Human Factors

Narrative: While performing the flight control check; noted binding when ailerons were deflected 1/2 way to the right. Asked the captain if he was restricting movement; he was not. Pushed to full deflection. Ailerons initially stuck at full deflection; then when pushed back left froze at 1/2 deflection. Reported the malfunction to ground and taxied back to parking. NOTE: I also noticed this on the ground during flight control check at ZZZ; but it was a temporary 'hitch' when moved right with no recurrence. After the initial sluggish feeling; which was very transient; there was no more odd feeling in the controls. I assumed a burble in the hydraulic line from sitting in depot or something of that nature that worked itself out and did not require further attention. It appears from the maintenance log that the left aileron was binding; interfering with a panel on the wing. It was supposedly flight checked before we got it. Since the FCF (Functional Check Flight) crew didn't notice anything; I can only assume it happened after they left and before we got to the plane. It is impossible in my opinion to damage that area without running something into the aircraft from behind; and since we did not back the plane or push back at all; I don't see how aircrew could prevent this damage.


Second narrative: During taxi out when First Officer (FO) did his control check the yoke and ailerons stuck approximately 5 to 6 degrees deflection to the right. Taxied aircraft back to gate and shutdown. I did not feel anything hit the aircraft during loading; we pushed back out of gate with a wing walker tail South on to B and did not hit anything during push back. FO did not see any damage to aircraft during his walk around. I actually looked at the aileron after we blocked in to confirm that it was in fact stuck in an up position and did not see any damage from the ground. The aircraft was coming out of C check and was flown by myself and FO empty a couple hours prior to the ground turn back. The aircraft was parked on the ramp in front of the maintenance hangar at ZZZ. We started and powered out with a marshaller and a wing walker making an approximately 45 degree turn before wave off. During the flight control check FO thought he felt resistance when moving the aileron to the right. He asked me if the yoke was hitting my leg and I told him no. He re-accomplished the check and did not feel resistance that time. We completed the before take-off checklist and flew uneventfully with myself as the pilot flying. The controls did not feel unusual during the flight. Landing and taxi in were normal. We were later told there was damage to aileron causing the flight controls to stick. Obviously it was human error if someone struck the aileron and damaged it. I suspect the aircraft was already damaged when we picked it up in ZZZ. I can't prove that though.


Synopsis: After pushback; B757 flight crew reports detecting aileron binding during a flight control check and returns to the gate. Damage to an aileron is discovered and it is suspected that it occurred prior to the previous flight; but was not detected by the crew.