Airworthiness Directives; Honeywell, Inc. Part Number HG1075AB05 and HG1075GB05 Inertial Reference Units

This amendment adopts a new airworthiness directive (AD) that applies to certain Honeywell, Inc. part number (P/N) HG1075AB05 and HG1075GB05 inertial reference units (IRU) that are installed on aircraft. This AD requires you to inspect the affected IRU's for proper function and remove the IRU either immediately or at a certain time depending on the result of the inspection. This AD is the result of a report that these IRU's may not function when using backup battery power in certain installations. The actions specified by this AD are intended to ensure the correct transition of the IRU to backup battery power upon the loss of primary power. Failure of an IRU to transition to backup battery power could result in loss of attitude, heading, and position reference and lead to the pilot making flight decisions that put the aircraft in unsafe flight conditions.