Airworthiness Directive · Amendment 39-22140 · Turbine engine accessory drive
CFM International, S.A. Turbofan Engines
This AD applies to CFM International, S.A. (CFM) LEAP-1B21, LEAP-1B23, LEAP-1B25, LEAP-1B27, LEAP-1B28, LEAP-1B28B1, LEAP-1B28B2, LEAP-1B28B2C, LEAP-1B28B3, LEAP-1B28BBJ1, and LEAP-1B28BBJ2 model turbofan engines with an installed inner radial drive shaft (RDS) with a serial number listed in Additional Information, paragraph 6.A., Table 1, of CFM Service Bulletin (SB) LEAP-1B-72-00-0365-01A-930A-D, Issue 003-00, dated April 26, 2022 (CFM SB LEAP-1B-72-00-0365-01A-930A-D).
The FAA is adopting a new airworthiness directive (AD) for certain CFM International, S.A. (CFM) LEAP-1B model turbofan engines. This AD was prompted by multiple commanded in-flight shutdowns (IFSDs) due to inner radial drive shaft (RDS) failure. This AD requires initial and repetitive inspections of the transfer gearbox (TGB) scavenge screens and, depending on the results of the inspections, replacement or rework of the affected inner RDS. As a mandatory terminating action to the initial and repetitive inspections of the TGB scavenge screens, this AD requires replacement or rework of the affected inner RDS. This AD also prohibits the installation of an engine with an affected inner RDS onto an airplane that already has one engine with an affected inner RDS installed. The FAA is issuing this AD to address the unsafe condition on these products.
(1) Before exceeding 50 flight hours (FHs) after the effective date of this AD, and thereafter at intervals not to exceed 50 FHs from the previous inspection, inspect the transfer gearbox (TGB) TGB1 and TGB2 scavenge screens in accordance with the Accomplishment Instructions, paragraph 5.A.(1), of CFM SB LEAP-1B-72-00-0365-01A-930A-D.
(2) If, during any inspection required by paragraph (g)(1) of this AD, any metallic particles are found, before further flight, perform the actions in the Accomplishment Instructions, paragraphs 5.A.(2) and (3), of CFM SB LEAP-1B-72-00-0365-01A-930A-D. Where paragraph 5.A.(3)(b) of CFM SB LEAP-1B-72-00-0365-01A-930A-D specifies to remove the engine, this AD instead requires replacement or rework of the inner RDS in accordance with the Accomplishment Instructions, paragraph 5.A., of CFM SB LEAP-1B-72-00-0258-01A-930A-C Issue 002, dated September 15, 2020 (CFM SB LEAP-1B-72-00-0258-01A-930A-C).
As a mandatory terminating action to the initial and repetitive inspections of the TGB1 and TGB2 scavenge screens required by paragraph (g)(1) of this AD, at the next piece-part exposure after the effective date of this AD, replace or rework the inner RDS in accordance with the Accomplishment Instructions, paragraph 5.A., of CFM SB LEAP-1B-72-00-0258-01A-930A-C.
After the effective date of this AD, do not install an engine with an affected inner RDS onto an airplane that already has one engine with an affected inner RDS installed.
For the purpose of this AD, “piece-part exposure” is when the fan frame shroud is separated from the fan hub.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
