An Airworthiness Directive issued by Transport Canada yesterday requires a general visual inspection of the left and right main landing gear system and main landing gear retract actuator jam nut on all Bombardier Q400s. The AD also calls for an immediate detailed visual inspection of main landing gear retract actuators that have accumulated 8,000 or more landings, or that have flown in service for more than four years since new, whichever comes first. Bombardier estimates that part of the AD affects some 85 aircraft.
Bombardier has sent two separate air safety teams to the sites of the recent incidents in which the right landing gear of two SAS Q400s collapsed upon landing. The first incident occurred in Aalborg, Denmark, on September 9. The second, which occurred yesterday in Vilnius, Lithuania, prompted Bombardier to ask operators to ground any Q400 that had accumulated more than 10,000 cycles. The action resulted in the grounding of some 60 airplanes and the cancellation of more than 300 flights.