Airworthiness Directive · Amendment 39-21652 · Engine controls
General Electric Company Turbofan Engines
Superseded. A later AD replaced this one: AD 2025-07-10. Comply with the one in force.
This AD applies to General Electric Company (GE) GE90-110B1 and GE90-115B model turbofan engines.
The FAA is adopting a new airworthiness directive (AD) for all General Electric Company (GE) GE90-110B1 and GE90-115B model turbofan engines. This AD was prompted by an in-service occurrence of loss of engine thrust control resulting in uncommanded high thrust. This AD requires initial and repetitive replacement of the full authority digital engine control (FADEC) integrated circuit (MN4) microprocessor. The FAA is issuing this AD to address the unsafe condition on these products.
(1) Within the following compliance times after the effective date of this AD, replace the FADEC MN4 microprocessor using an approved overhaul procedure:
(i) For a FADEC MN4 microprocessor with 10,500 or more cycles since new (CSN), replace the FADEC MN4 microprocessor before accumulating 500 additional cycles on the FADEC MN4 microprocessor.
(ii) For a FADEC MN4 microprocessor with 5,000 CSN or more, but fewer than 10,500 CSN, replace the FADEC MN4 microprocessor at the next FADEC component shop visit or before accumulating 11,000 CSN on the FADEC MN4 microprocessor, whichever occurs first.
(2) Thereafter, repeat the replacement of the FADEC MN4 microprocessor at the first FADEC component shop visit after accumulating 5,000 CSN since the last replacement but before accumulating 11,000 CSN since the last replacement.
(1) For the purpose of this AD, an “approved overhaul procedure” is one of the following:
(i) Replacement of the FADEC MN4 microprocessor using FADEC International-approved maintenance procedures; or
(ii) Replacement of the FADEC MN4 microprocessor using the Accomplishment Instructions, paragraph 3.A., of GE GE90-100 Service Bulletin 73-0118, Revision 01, dated April 27, 2021.
(2) For the purpose of this AD, a “FADEC component shop visit” is the induction of the FADEC into a repair facility to perform internal maintenance on the FADEC.
