Summary
The FAA proposes to supersede Airworthiness Directive (AD) 2012-21-08, which applies to certain The Boeing Company Model 737-600, -700, -700C, -800, and -900 series airplanes. AD 2012-21-08 requires inspecting for part numbers of the operational program software (OPS) of the flight control computers (FCCs) and installing and testing an updated version of the FCC OPS. Since the FAA issued AD 2012-21-08, the FAA has determined that there is a new unsafe condition which must be addressed by an updated version of the FCC OPS. This proposed AD would retain the requirement to inspect for part numbers of the OPS of the FCCs, and add a new requirement to update the version of the FCC OPS if necessary. This proposed AD would also expand the applicability to include The Boeing Company Model 737-900ER series airplanes. The FAA is proposing this AD to address the unsafe condition on these products.