Event Description
During the initial climb phase, the amber leading edge flat light remained illuminated after the flaps were retracted from 5 degrees to 2 degrees. The flight crew required moderate aileron and rudder inputs to maintain wings-level flight. The flaps were cycled from 5 back to 2 degrees, but the same condition persisted. The second officer confirmed that the No. 7 slat was not retracting. The crew then extended the flaps to 15 degrees, which eliminated the rolling tendency. The flight returned to LaGuardia Airport.
Inspection Findings
Subsequent inspection revealed that an inboard slat track roller support bolt for the No. 7 slat had failed. The roller was found lodged between the inboard track and wing structure. The roller was seized, with several bearings missing, and little lubrication was evident. The bolt had fractured through a lubrication hole that the roller mounts over. The fracture faces exhibited striations and cupping. The total time on the bolt and roller was 18,815 hours.
Conclusion
The investigation identified that the failure of the No. 7 slat track roller support bolt, due to a fracture through the lubrication hole, prevented the slat from retracting, necessitating corrective flight control inputs and a return to the departure airport.