Date: 201912
Location: ZZZ.Airport, US
Light: Daylight
Aircraft: EMB ERJ 170/175 ER/LR
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Climb
Airspace: Class B ZZZ
ATC / advisory: Tower ZZZ
Aircraft component: Aileron
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Communication Breakdown
Second reporter function: Pilot Flying; Captain
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Overcame Equipment Problem
Contributing factors: Aircraft; Company Policy; Human Factors
Primary problem: Aircraft

Narrative: We arrived to the airplane in ZZZ at around XA:00 A.M. Maintenance was on board the aircraft. They informed us that the previous crew that flew the airplane in had stiffness with their aileron control and the feel was not what they were used to feeling. Maintenance was basically done with their procedures; so the Captain asked to do a check on the flight controls ourselves. The Captain and I went into the flight deck and tested the flight controls. There were no issues that the Captain [nor] I observed. Maintenance finished up and said everything was good on their end; and since everything felt good on our end; we accepted the aircraft for operation. Departing out of ZZZ Runway XX on the ZZZZZ climb; we made a left turn per our departure procedure. The Captain was the pilot flying. He stated that the previous crew was right; the ailerons do feel stiff. It wasn't until after we had aerodynamic loading on the aircraft that we felt the stiffness. He handed me the flight controls for a few seconds; so I could feel it. You had to put a pretty good amount of force to go from wings level to enter a turn. At no time was the plane uncontrollable; let alone did we feel the operational control of the aircraft was unsafe; but the ailerons were definitely stiff. This report is not for me to explain that we did something wrong; but merely to document multiple crews saying the same thing; and Maintenance saying the aircraft is good to return to service. If something like this were to happen again; the best thing for me to do is trust the previous crew; and refuse the aircraft until a more thorough check has been done; like a flight test.


Second narrative: We arrived at the aircraft about an hour prior to scheduled departure to find Maintenance onboard. I entered the flight deck to ask the Maintenance Technician what the problem was. He explained to me that the previous crew had refused the airplane citing aileron stiffness. He then told me they had checked extensively and could find nothing wrong. I asked if I could sit in the seat and try the flight controls. I asked the FO to try as well; and we were all in agreement that there was nothing apparent wrong with the ailerons. I felt no binding; had full authority and travel; and the control column centered up without any difficulty. As such; we accepted the plane for service.Upon departure; flying the ZZZZZ climb Runway XX; I immediately noticed stiffness once the controls were under aerodynamic loading. Out of about 10;000 feet I gave flight controls to the FO to see what he thought. We were both in agreement that while we were not having control difficulties; the aileron characteristics of the aircraft were definitely not what either of us were accustomed to. It seemed to take a little more force than normal to get the same input. We evaluated the nature of the discrepancy and saw no reason why we could not safely continue.Upon arrival in ZZZ1; I contacted Maintenance Control and documented for a second time the aileron stiffness; and strongly recommended they look further into the matter. I also notified the outbound crew that the aircraft definitely needed to be inspected more closely. I have over 4;000 hours of flight experience on the E-170/175. It is normally a very responsive airplane and demands little effort from the pilot to enact a change of flight path and attitude. I am writing this report not because I feel we made an unsafe decision. All we can do as flight crew is trust our maintenance processes; take the information we are given; and make our decision to accept or reject an aircraft based off of that information. What makes this report important is the insidious nature of the event; given that the problem was not able to be noticed on the ground; but rather immediately in flight. My immediate safety recommendation is that going forward any squawks about flight control abnormalities be treated with more attention; removing the aircraft from service and flight testing it to catch what may not be visible on the ground.


Synopsis: EMB-175 flight crew reported that during pre-flight; Maintenance informed them the inbound crew had written up a stiff aileron issue; but had tested OK on the ground. Flight crew decided to take the aircraft and experienced aileron stiffness while turning on departure; but elected to continue to destination.