Airworthiness Directive · Amendment 39-21104 · Turbine section
International Aero Engines, LLC Turbofan Engines
This AD applies to International Aero Engines, LLC (IAE) PW1122G-JM, PW1124G1-JM, PW1124G-JM, PW1127GA-JM, PW1127G1-JM, PW1127G-JM, PW1133G-JM, PW1133GA-JM, PW1130G-JM, and PW1129G-JM model turbofan engines with low-pressure turbine (LPT) 3rd-stage blade, part number (P/N) 5387343, 5387493, 5387473 or 5387503, installed.
The FAA is adopting a new airworthiness directive (AD) for all International Aero Engines, LLC (IAE) PW1122G-JM, PW1124G1-JM, PW1124G- JM, PW1127GA-JM, PW1127G1-JM, PW1127G-JM, PW1133G-JM, PW1133GA-JM, PW1130G-JM, and PW1129G-JM model turbofan engines with a certain low- pressure turbine (LPT) 3rd-stage blade installed. This AD requires initial and repetitive borescope inspections (BSI) of the turbine stator intermediate outer rear air seal (turbine piston seal) and, depending on the results of the inspection, replacement with a part eligible for installation. This AD was prompted by reports of failure of turbine piston seals leading to fracture of the LPT 3rd-stage blades. The FAA is issuing this AD to address the unsafe condition on these products.
(1) Perform a borescope inspection (BSI) of the turbine piston seal shiplap in accordance with the Accomplishment Instructions, For Engines Installed On Aircraft, paragraph B of Pratt & Whitney (P&W) Service Bulletin (SB) PW1000G-C-72-00-0154-00A-930A-D, Issue No. 004, dated February 14, 2020 (“P&W SB PW1000G-C-72-00-0154-00A-930A-D”), or the Accomplishment Instructions, For Engines Not Installed on Aircraft, paragraph A of P&W SB PW1000G-C-72-00-0154-00A-930A-D, as applicable, as follows:
(i) For engines operating on extended operations (ETOPS) flights, perform the BSI of the turbine piston seal shiplap within 15 days after the effective date of this AD.
(ii) For engines that do not operate on ETOPS flights, perform the BSI of the turbine piston seal shiplap within 45 days after the effective date of this AD.
(iii) Before further flight, remove from service any turbine piston seal found to exceed serviceable limits, as described in the Accomplishment Instructions, For Engines Installed On Aircraft, paragraph C.(1) and C.(2), of P&W SB PW1000G-C-72-00-0154-00A-930A-D.
(iv) If any turbine piston seal shiplap is found fractured and missing, before further flight, BSI the LPT 3rd-stage blades, and remove any LPT 3rd-stage blade found to exceed serviceable limits.
Note 1 to paragraph (g)(1)(iv): Guidance on determining LPT 3rd-stage blade serviceable limits can be found in Airbus Aircraft Maintenance Manual (AMM) TASK 72-53-00-200-801-A.
(2) Thereafter, repeat the BSI required by paragraph (g)(1) of the turbine piston seal as follows:
(i) For any turbine piston seal found intact (not fractured) during the last BSI, repeat the BSI within the intervals in Table 2, of P&W SB PW1000G-C-72-00-0154-00A-930A-D.
(ii) For any turbine piston seal found fractured during the last BSI, repeat the BSI every 200 flight cycles from the previous BSI to ensure proper engagement per the Accomplishment Instructions, For Engines Installed On Aircraft, paragraph C.(1) of P&W SB PW1000G-C-72-00-0154-00A-930A-D.
Removal of the LPT 3rd-stage blades, P/N 5387343, 5387493, 5387473, and 5387503, is a terminating action to the initial and repetitive BSI requirements of this AD.
