Summary
The FAA proposes to supersede an existing airworthiness directive (AD) that applies to certain Bombardier Model CL-600-2B19 (Regional Jet Series 100 & 440) airplanes. The existing AD currently requires revising the Airplane Flight Manual (AFM) to provide the flightcrew with revised procedures for checking the flap system. The existing AD also requires revising the maintenance program to provide procedures for checking the flap system, and performing follow-on actions, if necessary. This proposed AD would require installing new flap actuators, a new or retrofitted air data computer, a new skew detection system, and new airspeed limitation placards; and revising the AFM to include revised maximum allowable speeds for flight with the flaps extended, and a new skew detection system/crosswind-related limitation for take-off flap selection. This proposed AD is prompted by a number of cases of flap system failure that resulted in a twisted outboard flap panel. We are proposing this AD to prevent an unannunciated failure of the flap system, which could result in a flap asymmetry and consequent reduced controllability of the airplane.