Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to Rolls-Royce plc RB211-535E4 and - 535E4-B series turbofan engines. This proposal would require installation of an improved fuel flow governor that incorporates revised minimum compressor discharge P4 stop settings. This proposal is prompted by reports of engine rundowns during low idle descent during icing conditions. The actions specified by the proposed AD are intended to prevent compressor stall and subsequent engine rundown on one or both engines.