Summary
The FAA proposes to adopt a new airworthiness directive (AD) for all Honeywell International Inc. Model AS907-1-1A and AS907-2-1G engines. This proposed AD was prompted by reports of compressor surge, including a dual engine compressor surge, during takeoff climb out through a steep temperature inversion, causing a loss of engine thrust control. This proposed AD would require either the replacement of a certain electronic control unit (ECU) software version installed on AS907-1-1A engines with updated software or the replacement of certain ECUs installed on AS907-1-1A engines with ECUs eligible for installation. This proposed AD would also require the replacement of certain ECUs installed on AS907-2-1G engines with ECUs eligible for installation. The FAA is proposing this AD to address the unsafe condition on these products.