AD 2018-26-01

We are superseding Airworthiness Directive (AD) 2018-18-01 for all CFM International S.A. (CFM) Model CFM56-7B turbofan engines. AD 2018-18-01 required initial and repetitive inspections of certain fan blades and, if they fail the inspection, their replacement with parts eligible for installation. This AD requires the same initial and repetitive inspections but revises the compliance time for the initial inspections and revises the installation prohibition based on the updated compliance time. This AD was prompted by further analysis by the manufacturer that indicated a need to reduce the initial fan blade inspection interval based on an ongoing root cause investigation of an April 2018 engine failure. We are issuing this AD to address the unsafe condition on these products.

Final rule; request for comments.

Adoption of the Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0 1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

Sec. 39.13 [Amended]

0 2. The FAA amends Sec. 39.13 by removing Airworthiness Directive (AD) 2018-18-01, Amendment 39-19380 (83 FR 49272, October 1, 2018) and adding the following new AD:

2018-26-01 CFM International S.A.: Amendment 39-19531; Docket No. FAA-2018-1039; Product Identifier 2018-NE-14-AD.

(a) Effective Date

This AD is effective January 10, 2019.

(b) Affected ADs

This AD replaces AD 2018-18-01, Amendment 39-19380 (83 FR 49272, October 1, 2018).

(c) Applicability

This AD applies to CFM International S.A.(CFM) CFM56-7B20, CFM56-7B22, CFM56-7B22/B1, CFM56-7B24, CFM56-7B24/B1, CFM56-7B26, CFM56-7B26/B2, CFM56-7B27, CFM56-7B27A, CFM56-7B26/B1, CFM56-7B27/ B1, CFM56-7B27/B3, CFM56-7B20/2, CFM56-7B22/2, CFM56-7B24/2, CFM56- 7B26/2, CFM56-7B27/2, CFM56-7B20/3, CFM56-7B22/3, CFM56-7B22/3B1, CFM56-7B24/3, CFM56-7B24/3B1, CFM56-7B26/3, CFM56-7B26/3B1, CFM56- 7B26/3B2, CFM56-7B27/3, CFM56-7B27/3B1, CFM56-7B27/3B3, CFM56-7B27A/ 3, CFM56-7B26/3F, CFM56-7B26/3B2F, CFM56-7B27/3F, CFM56-7B27/3B1F, CFM56-7B20E, CFM56-7B22E, CFM56-7B22E/B1, CFM56-7B24E, CFM56-7B24E/ B1, CFM56-7B26E, CFM56-7B26E/B1, CFM56-7B26E/B2, CFM56-7B27AE, CFM56-7B27E, CFM56-7B27E/B1, CFM56-7B27E/B3, CFM56-7B26E/F, CFM56- 7B26E/B2F, CFM56-7B27E/F, and CFM56-7B27E/B1F turbofan engine models.

(d) Subject

Joint Aircraft System Component (JASC) Code 7230, Turbine Engine Compressor Section.

(e) Unsafe Condition

This AD was prompted by further analysis by the manufacturer that indicated a need to reduce the initial fan blade inspection requirement based on its ongoing root cause investigation of an April 2018 engine failure that resulted in one fatality. We are issuing this AD to prevent failure of the fan blade. The unsafe condition, if not addressed, could result in failure of the fan blade, the engine inlet cowl disintegrating and debris penetrating the fuselage, causing a loss of pressurization, and prompting an emergency descent.

(f) Compliance

Comply with this AD within the compliance times specified, unless already done.

(g) Required Actions

(1) Perform an ultrasonic inspection (USI) or eddy current inspection (ECI) of the concave and convex sides of the fan blade dovetail as follows:
(i) For a fan blade with less than or equal to 16,000 cycles since new (CSN), inspect prior to accumulating 17,000 CSN.
(ii) For a fan blade with more than 16,000 and less than 20,000 CSN, inspect within 1,000 cycles but no later than 20,000 CSN.
(iii) For a fan blade with 20,000 or more CSN, inspect before further flight.
(iv) Thereafter, repeatthis inspection no later than 1,600 cycles since the last inspection, or within 450 cycles after October 16, 2018, the effective date of AD 2018-18-01, whichever occurs later.
(v) Use the Accomplishment Instructions, paragraphs 3.A.(3)(a) through (i), of CFM International Service Bulletin (SB) CFM56-7B S/B 72-1033, Revision 3, dated November 6, 2018, to perform a USI or use the instructions in subtask 72-21-01-220-091, of task 72-21-01-200- 001, from CFM CFM56-7B Engine Shop Manual, Revision 57, dated January 15, 2018, to perform an ECI.
(2) If any unserviceable indication, as specified in the applicable service information in paragraph (g)(1)(v) of this AD, is found during the inspections required by paragraph (g) of this AD, replace the fan blade before further flight with a part eligible for installation.

(h) Installation Prohibition

Do not install any replacement fan blade unless it meets one of the following criteria:
(1) The replacement fan blade has fewer than 17,000 CSN, or;
(2) The replacement fan blade has been inspected, per paragraph (g)(1) of this AD, within the last 1,600 cycles before installation.

(i) Definition

For the purpose of this AD, a ``replacement fan blade'' is a fan blade that is being installed into an engine from which it was not previously removed. Removing and reinstalling a fan blade for the purpose of relubrication is not subject to the Installation Prohibition of this AD.

(j) Credit for Previous Actions

You may take credit for the actions that are required by paragraph (g) of this AD, if you performed those actions before the effective date of this AD using CFM SB CFM56-7B S/B 72-1019, dated March 24, 2017; CFM SB CFM56-7B S/B 72-1019, Revision 1, dated June 13, 2017; CFM SB CFM56-7B S/B 72-1024, dated July 26, 2017; CFM SB CFM56-7B S/B 72-1033 dated April 20, 2018; CFM SB CFM56-7B S/B 72- 1033, Revision 1, dated May 9, 2018; or CFM International SB CFM56- 7B S/B 72-1033, Revision 2, dated July 27, 2018; or performed an ECI using the instructions in task 72-21-01-200-001, subtask 72-21-01- 220-091 of CFM56-7B Engine Shop Manual, earlier than Revision 57, dated January 15, 2018.

(k) Alternative Methods of Compliance (AMOCs)

(1) The Manager, ECO 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 certification office, send it to the attention of the person identified in paragraph (l) of this AD. You may email your request to: ANE-AD-AMOC@faa.gov.
(2) 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.
(3) For service information that contains steps that are labeled as Required for Compliance (RC), the provisions of paragraphs (k)(3)(i) and (k)(3)(ii) of this AD apply.
(i) The steps labeled as RC, including substeps under an RC step and any figures identified in an RC step, must be done to comply with the AD. An AMOC is required for any deviations to RC steps, including substeps and identified figures.
(ii) Steps not labeled as RC may be deviated from using accepted methods in accordance with the operator's maintenance or inspection program without obtaining approval of an AMOC, provided the RC steps, including substeps and identified figures, can still be done as specified, and the airplane can be put back in an airworthy condition.
(4) AMOCs approved previously for AD 2018-10-11 (83 FR 22836, May 17, 2018) and AD 2018-18-01 (83 FR 49272, October 1, 2018) are approved as AMOCs for the corresponding provisions of this AD.

(l) Related Information

For more information about this AD, contact Christopher McGuire, Aerospace Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone: 781-238-7120; fax: 781-238-7199; email: chris.mcguire@faa.gov.

(m) Material Incorporated by Reference

(1) The Director of the Federal Register approved the incorporation by reference (IBR) of the service information listed in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.

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(2) You must use this service information as applicable to do the actions required by this AD, unless the AD specifies otherwise.
(3) The following service information was approved for IBR on January 10, 2019.
(i) CFM International (CFM) Service Bulletin CFM56-7B S/B 72- 1033, Revision 3, dated November 6, 2018.
(ii) [Reserved]
(4) The following service information was approved for IBR on May 14, 2018 (83 FR 19176, May 2, 2018).
(i) Subtask 72-21-01-220-091, of Task 72-21-01-200-001, from the CFM CFM56-7B Engine Shop Manual, Revision 57, dated January 15, 2018.
(ii) [Reserved]
(5) For CFM service information identified in this AD, contact CFM International Inc., Aviation Operations Center, 1 Neumann Way, M/D Room 285, Cincinnati, OH 45125; phone: 877-432-3272; fax: 877- 432-3329; email: aviation.fleetsupport@ge.com.
(6) You may view this service information at the FAA, Engine and Propeller Standards Branch, 1200 District Avenue, Burlington, MA 01803. For information on the availability of this material at the FAA, call 781-238-7759.
(7) You may view this service information that is incorporated by reference at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal-register/cfr/ibr-locations.html.

Discussion

We issued AD 2018-18-01, Amendment 39-19380 (83 FR 49272, October 1, 2018), (``AD 2018-18-01''), for all CFM model CFM56-7B turbofan engines. AD 2018-18-01 required initial and repetitive ultrasonic inspections (USI) or eddy current inspection (ECI) of certain fan blades and, if they fail the inspection, their replacement with parts eligible for installation. AD 2018-18-01 resulted from analysis by the manufacturer that indicated a need to reduce the repetitive fan blade inspection interval based on ongoing root cause investigation of an April 2018 engine failure. The April 2018 engine failure was the result of a fractured fan blade leading to the engine inlet cowl disintegrating and debris penetrating the fuselage, causing a loss of pressurization and prompting an emergency descent. One passenger fatality occurred as a result. We issued AD 2018-18-01 to reduce the repetitive inspection interval from 3,000 cycles to 1,600 cycles.

Actions Since AD 2018-18-01 Was Issued

Since we issued AD 2018-18-01, CFM gained a better understanding of the fan blade failures based on the inspections and further analysis of the detected cracks and the April 2018 event. As a result, CFM has published CFM International Service Bulletin (SB) CFM56-7B S/B 72-1033, Revision 3, dated November 6, 2018, to reduce the initial inspection requirement from 20,000 cycles since new (CSN) to 17,000 CSN. We are issuing this AD to address the unsafe condition on these products.

Related Service Information Under 1 CFR Part 51

We reviewed CFM International SB CFM56-7B S/B 72-1033, Revision 3, dated November 6, 2018, and Subtask 72-21-01-220-091, of Task 72-21-01- 200-001, from the CFM56-7B Engine Shop Manual (ESM), Revision 57, dated January 15, 2018. CFM International SB CFM56-7B S/B 72-1033, Revision 3, describes procedures for performing a USI of the affected fan blades. Subtask 72-21-01-220-091, of Task 72-21-01-200-001, from theCFM56-7B ESM, describes procedures for performing an ECI of the affected fan blades. This service information 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.

Other Related Service Information

We also reviewed CFM SB CFM56-7B S/B 72-1019, dated March 24, 2017; CFM SB CFM56-7B S/B 72-1019, Revision 1, dated June 13, 2017; CFM SB CFM56-7B S/B 72-1024, dated July 26, 2017; CFM International SB CFM56- 7B S/B 72-1033, Revision 2, dated July 27, 2018; CFM SB CFM56-7B S/B 72-1033, Revision 1, dated May 9, 2018; CFM SB CFM56-7B S/B 72-1033, dated April 20, 2018; and General Electric Field Support Technology (FST) Procedure 2370, dated December 9, 2016. These SBs and the FST provide information on performing the USI.

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FAA's Determination

We are issuing this AD because we evaluated all the relevant information and determined the unsafe condition described previously is likely to exist or develop in other products of the same type design.

AD Requirements

This AD requires initial and repetitive USI or ECI of certain fan blades and, if they fail the inspection, their replacement with parts eligible for installation.

Interim Action

We consider this AD interim action. An investigation to determine the cause of the failure is ongoing, and we may consider additional rulemaking if final action is identified.

FAA's Justification and Determination of the Effective Date

An unsafe condition exists that requires the immediate adoption of this AD without providing an opportunity for public comments prior to adoption. The FAA has found that the risk to the flying public justifies waiving notice and comment prior to adoption of this rule. Due to the reduction in the initial inspection interval, some fan blades have reached or exceeded the revised initial inspection threshold and will require inspection within 1,000 cycles after the effective date of this AD. Because of this, the compliance time for the required action is shorter than the time necessary for the public to comment and for the FAA to issue the final rule to ensure the unsafe condition is addressed. Therefore, we find good cause that notice and opportunity for prior public comment are impracticable. In addition, for the reasons stated above, we find that good cause exists for making this amendment effective in less than 30 days.

Comments Invited

This AD is a final rule that involves requirements affecting flight safety, and we did not provide you with notice and an opportunity to provide your comments before it becomes effective. However, we invite you to send any written data, views, or arguments about this final rule. Send your comments to an address listed under the ADDRESSES section. Include the docket number FAA-2018-1039 and product identifier 2018-NE-14-AD at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this final rule. We will consider all comments received by the closing date and may amend this final rule because of those comments.
We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this final rule.

Costs of Compliance

We estimate that this AD affects 3,716 engines installed on 1,858 airplanes of U.S. registry.
We estimate the following costs to comply with this AD:

Estimated Inspection Costs ----------------------------------------------------------------------------------------------------------------
Cost per Cost on U.S.
Action Labor cost Parts cost product operators ---------------------------------------------------------------------------------------------------------------- Inspect engine fan blade.............. 2 work-hours x $85 per $0 $170 $631,720
hour = $170. ----------------------------------------------------------------------------------------------------------------

We estimate the following costs to complete any necessary replacement of a single fan blade that would be required based on the results of the inspection. We have no way of determining the number of engines that might need fan blades to be replaced.

On-Condition Costs ----------------------------------------------------------------------------------------------------------------
Cost per
Action Labor cost Parts cost product ---------------------------------------------------------------------------------------------------------------- Replace fan blade............................. 1 work-hour x $85 per hour = $85 $51,400 $51,485 ----------------------------------------------------------------------------------------------------------------

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.
We are 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.
This AD is issued in accordance with authority delegated by the Executive Director, Aircraft Certification Service, as authorized by FAA Order 8000.51C. In accordance with that order, issuance of ADs is normally a function of the Compliance and Airworthiness Division, but during this transition period, the Executive Director has delegated the authority to issue ADs applicable to engines, propellers, and associated appliances to the Manager, Engine and Propeller Standards Branch, Policy and Innovation Division.

Regulatory Findings

This AD will not have federalism implications under Executive Order 13132. This AD will 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 that this AD:
(1) Is not a ``significant regulatory action'' under Executive Order 12866,
(2) Is not a ``significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979),
(3) Will not affect intrastate aviation in Alaska, and

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(4) Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.