Action
Notice of proposed rulemaking (NPRM).
Summary
We propose to supersede an existing airworthiness directive (AD) that applies to 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. The existing AD currently requires inspecting the intermediate-pressure (IP) compressor rotor shaft rear balance land for cracks. Since we issued that AD, we received reports of one RB211-Trent 700 and two additional RB211-Trent 800 IP compressor rotor shafts that have been found cracked. This proposed AD would continue to require initial inspections, add additional inspections, and an optional terminating action. The cracking identified above could lead to IP compressor rotor shaft failure, uncontained engine failure, and damage to the airplane. We are proposing this AD to correct the unsafe condition on these products.