Summary
The FAA proposes to adopt a new airworthiness directive (AD) for all The Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes. This proposed AD was prompted by a report indicating that adjusting the upper locking hydraulic actuator proximity sensor targets in accordance with certain data in the aircraft maintenance manual (AMM) could result in incorrect upper locking hydraulic actuator indications, which could result in a thrust reverser that indicates 'locked' when it is not locked. This proposed AD would require conducting measurements, tests, and operational checks of the upper locking hydraulic actuator for certain functions, performing applicable on-condition actions, and revising the existing maintenance or inspection program, as applicable, to incorporate certain certification maintenance requirements (CMR). The FAA is proposing this AD to address the unsafe condition on these products.