AD 2018-08-02

(1) Inspect the IPC stage 1 rotor blades before exceeding the applicable initial inspection thresholds specified in Table 1 of RR Alert Non-Modification Service Bulletin (NMSB) Trent 1000 72-AK060, dated April 13, 2018, or within 80 flight cycles (FCs) after the effective date of this AD, whichever occurs later. If Direct Accumulation Count cycles, as specified in Table 1 of RR Alert NMSB Trent 1000 72-AK060, are not available, then use FCs, regardless of Engine Health Monitoring alerts. Thereafter at intervals not to exceed 200 FCs, repeat the inspection of the IPC stage 1 rotor blades. Use the Accomplishment Instructions, paragraph 3.A., of RR Alert NMSB Trent 1000 72-AK060, dated April 13, 2018 to perform the inspections.

(2) Perform an initial inspection of the IPC stage 2 rotor blades and IPC shaft stage 2 dovetail posts, using the Accomplishment Instructions, paragraph 3.B., of RR Alert NMSB Trent 1000 72-AK060, dated April 13, 2018. Perform the initial inspection based on engine operations as specified in the following paragraphs and within the following compliance times:

(i) For engines with less than 300 FCs since new on the effective date of this AD:

(A) For engines that are not operated on ETOPS (extended operations) flights, prior to exceeding 300 FCs or within 50 days after the effective date of this AD, whichever occurs later.

(B) For engines that are operated on ETOPS flights, before exceeding 300 FCs or before the next ETOPS flight, whichever occurs later.

(ii) For engines with 300 or more FCs since new on the effective date of this AD:

(A) For engines that are not operated on ETOPS flights, prior to exceeding 50 days after the effective date of this AD or within 80 FCs since the last inspection performed in accordance with RR Alert NMSB Trent 1000 72-AJ819, whichever occurs later. This inspection is not to exceed 200 FCs since the previous inspection.

(B) For engines that are operated on ETOPS flights, before the next ETOPS flight, or within 80 FCs since the last inspection performed in accordance with RR Alert NMSB Trent 1000 72-AJ819, whichever occurs later.

(3) Thereafter, at intervals not to exceed 80 FCs, repeat the inspections of the IPC stage 2 rotor blades and IPC shaft stage 2 dovetail posts required by paragraph (g)(2) of this AD. Use the Accomplishment Instructions, paragraph 3.B., of RR Alert Trent 1000 72-AK060, dated April 13, 2018, to perform these inspections.

(4) For engines involved in ETOPS operations, inspect the rear face of IPC stage 2 rotor blades, part number KH25730, at each inspection interval defined in paragraph (g)(3) of this AD in accordance with the Accomplishment Instructions, paragraph 3.C., of RR Alert Trent 1000 72-AK060, dated April 13, 2018.

(5) As of the effective date of this AD, before the next flight after each occurrence where engine operation in asymmetric power conditions was sustained for more than 30 minutes at less than 25,000 feet, either resulting from engine power reduction, or from engine in-flight shut-down (IFSD), perform an on-wing borescope inspection of the IPC stage 2 rotor blades and IPC shaft stage 2 dovetail posts on the unaffected engine (no power reduction, no IFSD) installed on the airplane. Use the Accomplishment Instructions, either paragraph 3.B. for engines not involved in ETOPS operations, or paragraphs 3.B. and 3.C. for engines involved in ETOPS operations, of RR Alert NMSB Trent 1000 72-AK060, dated April 13, 2018, to perform this inspection.

(6) If any IPC stage 1 rotor blade, IPC stage 2 rotor blade, or an IPC shaft stage 2 dovetail post is found cracked during any inspection required by this AD, replace the part with a part eligible for installation before further flight.

For the purpose of this AD, flight cycles indicated in paragraph (g)(1) of this AD are those accumulated by the engine. FCs indicated in paragraph (g)(2) of this AD are those accumulated by each affected IPC stage 2 rotor blade since first installation on an engine. If FCs accumulated by an affected IPC stage 2 rotor blade are unknown, then engine FCs since new apply.