What happened
Shortly after departure, the first officer observed stiffness in the flight controls while attempting to roll the aircraft to the left. Following an assessment of the situation, the captain decided to continue the climb. After reaching level flight, the crew observed that the control stiffness increased in proportion to the airspeed. This phenomenon persisted during the descent phase, with the first officer noting that resistance to left roll inputs increased as the aircraft accelerated.
In an attempt to relieve the pressure, the captain utilized aileron trim. However, once the trim indicator reached the first index, the control wheel suddenly snapped approximately 25 degrees, causing the airplane to bank to the right. As the aircraft slowed during the approach, the crew noted that the roll control stiffness decreased. Following the landing, a full control check was performed, which revealed no abnormal indications regarding the spoilers or ailerons.
The investigation
A post-flight inspection identified several mechanical discrepancies believed to have contributed to the stiff flight controls:
- High tension in the right control yoke chain
- The right aileron spring tab hinge bearing failed to rotate freely
- Low tension on the left aileron spring tab aft spring and a worn contact stud
- Low tension on the right aileron spring tab and a worn contact stud
- The left aileron hinge bearing failed to rotate freely