Airworthiness Directives; Bombardier, Inc. Airplanes
We are superseding Airworthiness Directive (AD) 2014-03-05, for certain Bombardier, Inc. Model BD-700-1A10 airplanes. AD 2014-03-05 required modification of the air data probes and sensors. This new AD continues to require modification of the air data probes and sensors. This new AD also adds airplanes to the applicability. This AD was prompted by a report that the manufacturer has determined that some completion centers used the heater current/brake temperature monitor unit (HBMU) logic circuit to control the line voltage of the drain mast heaters. We are issuing this AD to detect and correct an unannunciated failure of two pitot static probe heaters, which could affect controllability of the airplane in icing conditions.