The FAA proposes to adopt a new airworthiness directive (AD) for all CFM International, S.A. (CFM) Model CFM56-7B engines. This proposed AD was prompted by an event involving a ...
The FAA proposes to adopt a new airworthiness directive (AD) for all CFM International, S.A. (CFM) Model CFM56-7B engines. This proposed AD was prompted by an event involving a CFM Model CFM56-7B26/3 engine where a fan blade separated and resulted in an engine in-flight shutdown (IFSD) with debris penetrating the fuselage, which caused a loss of pressurization and prompted an emergency descent. This proposed AD would require a visual inspection of the fan blades for findings considered not serviceable and, depending on the results of the inspection, replacement with a serviceable part and additional fan blade inspections. This proposed AD would also require sending the inspection results to CFM if any finding considered not serviceable is found. The FAA is proposing this AD to address the unsafe condition on these products.
DATES:
The FAA must receive comments on this proposed AD by November 27, 2026.
ADDRESSES:
You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, by any of the following methods:
Federal eRulemaking Portal:
Go to
regulations.gov. Follow the instructions for submitting comments.
Fax:
(202) 493-2251.
Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590.
Hand Delivery:
Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.
AD Docket:
You may examine the AD docket at
regulations.gov
under Docket No. FAA-2026-11817; or in person at Docket Operations between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this NPRM, any comments received, and other information. The street address for Docket Operations is listed above.
Material Incorporated by Reference:
For CFM material identified in this proposed AD, contact CFM, GE Aviation Fleet Support, 1 Neumann Way, M/D Room 285, Cincinnati, OH 45215; phone: (877) 432-3272; email:aviation.fleetsupport@ge.com.
You may view this material at the FAA, Airworthiness Products Section, Operational Safety Branch, 1200 District Avenue, Burlington, MA 01803. For information on the availability of this material at the FAA, call (817) 222-5110.
FOR FURTHER INFORMATION CONTACT:
Alexei Marqueen, Aviation Safety Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198; phone: (781) 238-7178; email:
alexei.t.marqueen@faa.gov.
SUPPLEMENTARY INFORMATION:
Comments Invited
The FAA invites you to send any written relevant data, views, or arguments about this proposal. Send your comments using a method listed under the
ADDRESSES
section. Include “Docket No. FAA-2026-11817; Project Identifier AD-2026-01020-E” at the beginning of your comments. The most helpful comments reference a specific portion of the proposal, explain the reason for any recommended change, and include supporting data. The FAA will consider all comments received by the closing date and may revise this proposal because of those comments.
Except for Confidential Business Information (CBI) as described in the following paragraph, and other information as described in 14 CFR 11.35, the FAA will post all comments received, without change, to
regulations.gov, including any personal information you provide. The agency will also post a report summarizing each substantive verbal contact received about this NPRM.
Confidential Business Information
CBI is commercial or financial information that is both customarily and actually treated as private by its owner. Under the Freedom of Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public disclosure. If your comments responsive to this NPRM contain commercial or financial information that is customarily treated as private, that you actually treat as private, and that is relevant or responsive to this NPRM, it is important that you clearly designate the submitted comments as CBI. Please mark each page of your submission containing CBI as “PROPIN.” The FAA will treat such marked submissions as confidential under the FOIA, and they will not be placed in the public docket of this NPRM. Submissions containing CBI should be sent to Alexei Marqueen, Aviation Safety Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198. Any commentary that the FAA receives which is not specifically designated as CBI will be placed in the public docket for this rulemaking.
Background
The FAA received a report that a Boeing 737-800 Model airplane powered by CFM56-7B26/3 engines experienced a fan blade separation during flight that resulted in an engine IFSD with debris penetrating the fuselage, which caused a loss of pressurization and prompted an emergency descent. The manufacturer investigation into the root cause of the fan blade failure is ongoing, but preliminary investigation indicates deformation to the fan blades induced a localized vibratory response in the failed blade. This condition, if not addressed, could result in debris penetrating the fuselage and cause a loss of pressurization and prompt an emergency descent.
On April 17, 2018, a Southwest Airlines flight experienced a CFM56-7B engine failure due to a fractured fan blade that led to the engine inlet cowl
( printed page 67533)
disintegrating and debris penetrating the fuselage. The FAA has received no factual information that indicates that the April 17, 2018 incident on a Southwest Airlines flight is related to the unsafe condition addressed by this proposed AD. It is noted here for completeness only.
The FAA is providing a 30-day comment period for this NPRM instead of the standard 45-day comment period. This shortened timeframe is necessary to align the effective implementation of this safety action with the European Union Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Union, and in consideration of the recent in-service engine event. The FAA has determined that a 30-day comment period provides sufficient opportunity for public input while ensuring harmonization with EASA.
FAA's Determination
The FAA is issuing this NPRM after determining that the unsafe condition described previously is likely to exist or develop on other products of the same type design.
Material Incorporated by Reference Under 1 CFR Part 51
The FAA reviewed CFM Service Bulletin CFM56-7B S/B 72-1119, dated September 8, 2026, which specifies procedures for visual inspection of the fan blades for findings considered not serviceable (cracks, tears, tip curls, local distortion on leading edge), and additional inspections of adjacent (forward looking aft) fan blades. This material is reasonably available because the interested parties have access to it through their normal course of business or by the means identified in the
ADDRESSES
section.
Proposed AD Requirements in This NPRM
This proposed AD would require a visual inspection of the fan blades for findings considered not serviceable (cracks, tears, tip curls, local distortion on leading edge) and, depending on the results of the inspection, replacement with a serviceable part and additional fan blade inspections. This proposed AD would also require sending the inspection results to CFM if any unserviceable finding is found.
Interim Action
This AD is considered to be interim action. The inspection reports that are required by this AD will enable the manufacturer to obtain better insight into the nature, cause, and extent of the fan blade failure, and eventually allow the manufacturer to develop final action to address the unsafe condition. Once final action has been identified, the FAA might consider further rulemaking.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would affect 3,450 engines installed on airplanes of U.S. registry.
The FAA estimates the following costs to comply with this proposed AD:
Estimated Costs
Action
Labor cost
Parts cost
Cost per
product
Cost on U.S.
operators
Visually inspect fan blades
1 work-hour × $85 per hour = $85
$0
$85
$293,250
The FAA estimates the following costs to do any necessary replacements and additional inspections that would be required based on the results of the proposed inspection. The agency has no way of determining the number of engines that might need these replacements and additional inspections:
On-Condition Costs
Action
Labor cost
Parts cost
Cost per product
Remove and replace fan blade
1 work-hour × $85 per hour = $85
$51,400
$51,485
Inspect adjacent fan blade
2 work-hours × $85 per hour = $170
0
170
Report inspection results
1 work-hour × $85 per hour = $85
0
85
Paperwork Reduction Act
A federal agency may not conduct or sponsor, and a person is not required to respond to, nor shall a person be subject to a penalty for failure to comply with a collection of information subject to the requirements of the Paperwork Reduction Act unless that collection of information displays a currently valid OMB Control Number. The OMB Control Number for this information collection is 2120-0056. Public reporting for this collection of information is estimated to be approximately 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. All responses to this collection of information are mandatory. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to: Information Collection Clearance Officer, Federal Aviation Administration, 10101 Hillwood Parkway, Fort Worth, TX 76177-1524.
Authority for This Rulemaking
Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. Subtitle VII: Aviation Programs, describes in more detail the scope of the Agency's authority.
The FAA is issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701: General requirements. Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.
Regulatory Findings
The FAA determined that this proposed AD would not have federalism implications under Executive Order
( printed page 67534)
13132. This proposed AD would not have a substantial direct effect on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government.
For the reasons discussed above, I certify this proposed regulation:
(2) Would not affect intrastate aviation in Alaska, and
(3) Would not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.
This AD was prompted by an event involving a CFM Model CFM56-7B26/3 engine, which experienced a fan blade separation that resulted in an in-flight engine shutdown and debris penetrating the fuselage, causing a loss of pressurization and prompting an emergency descent. The FAA is issuing this AD to prevent failure of the fan blade. The unsafe condition, if not addressed, could result in debris penetrating the fuselage and cause a loss of pressurization and prompt an emergency descent.
(f) Compliance
Comply with this AD within the compliance times specified, unless already done.
(g) Definition
For the purpose of this AD, a “serviceable fan blade” is a new, zero-hour fan blade or a fan blade that has passed the inspections required by paragraph (h)(1) of this AD.
(h) Required Actions
(1) Perform a visual inspection of the fan blades in accordance with the Accomplishment Instructions, paragraph 3.C., of CFM Service Bulletin (SB) CFM56-7B S/B 72-1119, dated September 8, 2026 (CFM56-7B S/B 72-1119), as follows:
(i) For engines installed on aircraft as of the effective date of this AD, within 400 flight cycles or within 90 days after the effective date of this AD, whichever occurs first.
(ii) For engines not installed on aircraft as of the effective date of this AD, before further flight.
(2) If any findings considered not serviceable are detected, before further flight, do the following:
(i) Remove the fan blade from service and replace with a serviceable fan blade.
(ii) Perform an inspection of the adjacent clockwise (forward looking aft) fan blade for findings considered not serviceable in accordance with the Accomplishment Instructions, paragraph 3.D.(2), of CFM56-7B S/B 72-1119.
(iii) If any unserviceable finding is found during the inspection required by paragraph (h)(2)(ii) of this AD, before further flight, remove the fan blade from service and replace with a serviceable fan blade.
(i) Credit for Previous Actions
This paragraph provides credit for actions required by paragraph (h) of this AD, if those actions were performed prior to the effective date of this AD using the material identified in, and meeting the applicable conditions specified in, paragraphs (i)(1) through (3) of this AD.
(1) Credit is allowed for the actions required by paragraph (h) of this AD if an engine shop manual piece-part inspection was performed on each fan blade in the set within 100 flight cycles prior to the effective date of this AD; or
(2) Credit is allowed if the actions required by paragraph (h) of this AD were performed within 100 flight cycles prior to the effective date of this AD using CFM SB CFM56-7B S/B 72-1033, Revision 3, dated November 6, 2018; CFM56-7B S/B 72-1033, Revision 4, dated September 12, 2019; CFM56-7B S/B 72-1033, Revision 5, dated July 28, 2026; or CFM56-7B S/B 72-1033, Revision 6, dated August 14, 2026; or
(3) Credit is allowed if the actions required by paragraph (h) of this AD were performed using CFM SB CFM56-7B S/B 72-1118, dated June 1, 2026.
(j) Reporting Requirement
Report the results of the inspections required by paragraph (h) of this AD to CFM within 30 days after the inspection or within 30 days after the effective date of this AD, whichever occurs later, in accordance with the Accomplishment Instructions, paragraph 3.D.(3), of CFM56-7B S/B 72-1119.
(k) Alternative Methods of Compliance (AMOCs)
The Manager, AIR-520 Continued Operational Safety Branch, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request to your principal inspector or local Flight Standards District Office, as appropriate. If sending information directly to the manager of the AIR-520 Continued Operational Safety Branch, send it to the attention of the person identified in paragraph (l)(1) of this AD and email to:
AMOC@faa.gov. Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/certificate holding district office.
(l) Additional Information
(1) For more information about this AD, contact Alexei Marqueen, Aviation Safety Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198; phone: (781) 238-7178; email:
alexei.t.marqueen@faa.gov.
(2) For material identified in this AD that is not incorporated by reference, contact CFM International, S.A., GE Aviation Fleet Support, 1 Neumann Way, M/D Room 285, Cincinnati, OH 45215; phone: (877) 432-3272; email:
aviation.fleetsupport@ge.com.
(m) Material Incorporated by Reference
(1) The Director of the Federal Register approved the incorporation by reference (IBR) of the material listed in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
(2) You must use this material as applicable to do the actions required by this AD, unless the AD specifies otherwise.
(i) CFM Service Bulletin CFM56-7B S/B 72-1119, dated September 8, 2026.
(ii) [Reserved]
(3) For CFM material identified in this AD, contact CFM International, S.A., GE Aviation Fleet Support, 1 Neumann Way, M/D Room 285, Cincinnati, OH 45215; phone: (877)
( printed page 67535)
432-3272; email:
aviation.fleetsupport@ge.com.
(4) You may view this material at the FAA, Airworthiness Products Section, Operational Safety Branch, 1200 District Avenue, Burlington, MA 01803. For information on the availability of this material at the FAA, call (817) 222-5110.
14 CFR 11.43
5 U.S.C. 552
www.archives.gov/federal-register/cfr/ibr-locations