Federal Register Proposed Rules, Rules and Notices for September 3,2013

September 3,2013

RULES

Airworthiness Directives; Rolls-Royce plc (RR) Turbofan Engines [FR DOC# 2013-21108] SUMMARY: We are superseding airworthiness directive (AD) 2012-10-12 for all RR RB211-Trent 553-61, 553A2-61, 556-61, 556A2-61, 556B-61, 556B2- 61, 560-61, 560A2-61, 768-60, 772-60, 772B-60, 875-17, 877-17, 884-17, 884B-17, 892-17, 892B-17, and 895-17 turbofan engines. AD 2012-10-12 required inspecting the intermediate-pressure (IP) compressor rotor shaft rear balance land for cracks. We are issuing this AD to
require inspections of the IP compressor rotor shaft, as required by AD 2012- 10-12, to add on-wing inspections for the Trent 500 engines, and to add on-wing and in-shop inspections for the Trent 900 engines. This AD was prompted by detection of a crack in a Trent 500 IP compressor rotor shaft rear balance land during a shop visit. Further engineering evaluation, done by RR, concluded that the cracking may also exist in
Trent 900 engines. We are issuing this AD to detect cracking on the IP compressor rotor shaft rear balance land, which could lead to uncontained engine failure and damage to the airplane.

Airworthiness Directives; Rolls-Royce plc Turbofan Engines [FR DOC# 2013-21109] SUMMARY: We are adopting a new airworthiness directive (AD) for certain Rolls-Royce plc (RR) RB211-524B-02; -524B2-19; – 524B3-02; -524B4-02; – 524C2-19; -524D4-19; -524D4-B-19; -524D4-39; -535C-37; -535E4-37; – 535E4-B- 37, and -535E4-B-75 turbofan engines, and all RB211-524G2-19; – 524G3-19; -524H2-19; and -524H-36
turbofan engines. This AD requires a one-time inspection of the front combustion liner (FCL) metering panel to determine if it is made from N75 material and, if so, replacing it with an FCL made from C263 material. This AD was prompted by the discovery of a cracked and distorted FCL metering panel, which was made from N75 material. We are issuing this AD to prevent hot gases from burning through the engine casing, which could result in an under-cowl fire and damage to the airplane.