Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain The Boeing Company Model 727, 727C, 727-100, 727-100C, 727- 200, and 727-200F series airplanes. This proposed AD was prompted by reports of nuisance stick shaker activation while the airplane accelerated to cruise speed at the top of climb. This proposed AD was also prompted by an investigation of those reports that revealed that the angle of attack (AOA) (also known as angle of airflow) sensor vanes could not prevent the build-up of ice, causing the AOA sensor vanes to become immobilized, which resulted in nuisance stick shaker activation. This proposed AD would require a general visual inspection of the AOA sensors for certain AOA sensors, and replacement of affected AOA sensors. The FAA is proposing this AD to address the unsafe condition on these products.