Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain Bombardier, Inc., Model BD-700-1A10 and BD-700-1A11 airplanes. This proposed 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 proposed AD would require 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 proposing this AD to address the unsafe condition on these products.