Airworthiness Directives; Bombardier, Inc., Airplanes

The FAA is adopting a new airworthiness directive (AD) for certain Bombardier, Inc., Model BD-700-1A10 and BD-700-1A11 airplanes. This AD was prompted by reports of the loss of all air data system information provided to the flightcrew during flight; the air data system information was recovered as the airplane descended to lower altitudes. This AD requires revising the existing airplane flight manual (AFM) to update the Unreliable Airspeed and Landing Distance Factor emergency procedures, which provide instructions for the flightcrew to stabilize the airspeed and altitude. The FAA is issuing this AD to address the unsafe condition on these products.