Airworthiness Directives; Bombardier, Inc., Airplanes

The FAA is adopting a new airworthiness directive (AD) for all Bombardier, Inc., Model BD-100-1A10 airplanes. This AD was prompted by an investigation that indicated that one of the springs in the pitch trim switch of the horizontal stabilizer had failed. The failure of the spring could result in the airplane pitching nose down when actually commanded nose up. This AD requires a verification of the serial numbers of certain pitch trim switches, and replacement of the affected pitch trim switches with new ones in the pilot and co-pilot control wheels. This AD would also prohibit the installation of affected parts. The FAA is issuing this AD to address the unsafe condition on these products.