Summary
We propose to adopt a new airworthiness directive (AD) for certain Bombardier, Inc. Model DHC-8-102, -103, and -106 airplanes, and Model DHC-8-200, -300, and -400 series airplanes. This proposed AD was prompted by reports of excessive wear found in the clevis (bolt) hole where the rod assembly attaches to the rudder/brake pedal bellcrank, due to prolonged fretting. This proposed AD would require measuring the bellcrank clevis holes, inspecting for cracking of the bellcrank, and re-working the clevis holes with steel bushings, or replacing the bellcrank. We are proposing this AD to detect and correct a worn or cracked clevis hole, which could cause failure of the bellcrank on one side, with subsequent asymmetric braking and consequent runway excursion.