Airworthiness Directives; Bombardier, Inc., Airplanes

The FAA is adopting a new airworthiness directive (AD) for certain Bombardier, Inc., Model BD-100-1A10 airplanes. This AD was prompted by a design review of the avionic architecture of the pitch trim indication and alerting system that revealed software errors could generate misleading pitch trim indication to the crew, leading to incorrect horizontal stabilizer positioning at takeoff. This AD requires revising the Emergency Procedures and Normal Procedures of the existing airplane flight manual (AFM) to ensure the horizontal stabilizer is correctly configured prior to takeoff. The FAA is issuing this AD to address the unsafe condition on these products.