Tue, Aug 10, 2021
AD 2021-15-05 Prompted By An In-Service Occurrence Of Loss Of Engine Thrust Control
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. This AD is effective September 13, 2021.
Supplementary Information: The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to all GE GE90-110B1 and GE90-115B model turbofan engines. The NPRM published in the Federal Register on May 7, 2021 (86 FR 24554). The NPRM was prompted by an in-service occurrence of loss of engine thrust control resulting in uncommanded high thrust. The FAA received a report from the manufacturer of an in-service loss of engine thrust control that occurred on October 27, 2019, resulting in uncommanded high thrust.
Analysis by the manufacturer found accumulated thermal cycles of the MN4 integrated circuit in the FADEC, through normal operation, causes the solder ball joints to wear out and eventually fail over time. The FAA published AD 2020-20-17 (85 FR 63443, dated October 8, 2020) to prohibit dispatch of an airplane if certain status messages are displayed on the engine indicating and crew alerting system and if certain conditions are present per the manufacturer's service information. As a terminating action, AD 2020-20-17 also requires revision of the existing FAA-approved minimum equipment list (MEL) by incorporating into the MEL the dispatch restrictions listed in AD 2020-20-17. Since the effective date of AD 2020-20-17, the manufacturer published GE GE90-100 Service Bulletin (SB) 73-0118 R00, dated November 6, 2020, and Revision 01, dated April 27, 2021, to replace the FADEC MN4 microprocessor and solder. In the NPRM, the FAA proposed to require initial and repetitive replacement of the FADEC MN4
microprocessor using an approved overhaul procedure. The FAA is issuing this AD to address the unsafe condition on these products.
More News
Improvements Stack as Brand Readies for Mass Production Samson Sky updated followers on its flying car progress, describing some of the travails of the wind tunnel as they get clos>[...]
LAHSO An acronym for “Land and Hold Short Operation.” These operations include landing and holding short of an intersecting runway, a taxiway, a predetermined point, or>[...]
Dave Juwel's Aviation Marketing Stories ITBOA BNITBOB ... what does that mean? It's not gibberish, it's a lengthy acronym for "In The Business Of Aviation ... But Not In The Busine>[...]
Aero Linx: Space Medicine Association (SMA) The Space Medicine Branch was founded in 1951 as the first constituent organization of the Aerospace Medical Association (AsMA). In 2006>[...]
Back-Taxi A term used by air traffic controllers to taxi an aircraft on the runway opposite to the traffic flow. The aircraft may be instructed to back-taxi to the beginning of the>[...]