Bombardier Inc CL-600-2B19 N8505Q incident near Detroit, Michigan

Probable cause

The mechanic's incomplete securing of all the wheel well bin's fasteners, which resulted in separation of the bin from the airplane.

NTSB analysis

The operator reported that the flight crew received a main landing gear overheat fail message on the engine indication and crew alerting system as the landing gear was being retracted after takeoff. During the remainder of the flight, the message came on every 15 to 20 seconds, remained on for about 5 seconds, and then extinguished. The flight crew contacted maintenance control and were advised that the flight could continue to the destination since the message was intermittent. The airplane landed at its intended destination without incident. During postincident troubleshooting to determine the reason for the message, maintenance personnel discovered that the right wheel well bin, which incorporated the landing gear overheat temperature sensor, had departed the aircraft. Examination revealed that only 3 of the 11 fasteners that attached the bin to the fuselage remained in place, and those 3 fasteners retained torn sections of bin under their heads. According to the operator, the last maintenance that involved removal and reinstallation of the wheel well bin was the repair of a flap discrepancy six days prior to the incident. Subsequent to the repair, the airplane completed 29 flights before the incident flight. After the incident, the operator published a warning in its airplane maintenance manual cautioning mechanics not to use electric, battery, or pneumatic powered screw guns to secure wheel well bins.

Text from the NTSB. Open the NTSB docket for CEN11IA264 for the full record.