Airworthiness Directives; Bombardier, Inc. Airplanes

We propose to adopt a new airworthiness directive (AD) for certain Bombardier, Inc. Model DHC-8-400, -401, and -402 airplanes. This proposed AD was prompted by a report of a main landing gear (MLG) parking brake becoming dislodged from its mounting bracket due to an improperly installed quick release pin of the hand pump lever. This proposed AD would require removing the hand pump lever of the parking brake from the right-hand side nacelle. We are proposing this AD to prevent an unsecured lever from migrating from its stowed position, fouling against the MLG, and subsequently puncturing the nacelle structure, which could adversely affect the safe landing of the airplane.