Airworthiness Directives; Pratt & Whitney PW4000 Series 94-Inch Fan Turbofan Engines

概要

The FAA is adopting a new airworthiness directive (AD) for Pratt & Whitney (P&W) PW4052, PW4056, PW4060, PW4062, PW4152, PW4156A, PW4158, PW4460, and PW4462 turbofan engines. This AD requires a onetime visual inspection of all EEC-131 model electronic engine controls (EECs). This AD also requires the EECs to be identified, categorized by group number, marked, and replaced using a fleet management plan. This AD results from a report of an uncommanded engine in-flight shutdown due to defective EEC pulse width modulator (PWM) microcircuits. We are issuing this AD to prevent uncommanded in-flight engine shutdowns which could result in loss of thrust and prevent continued safe flight or landing.