AD 98-10-11

This amendment adopts a new airworthiness directive (AD) that is applicable to CFM International CFM56-3, -3B, -3C, -5, -5B, and -5C series turbofan engines. This action supersedes telegraphic AD T97-25-51 that currently requires removal of one engine from an aircraft, and replacement with a serviceable engine or replacement of parts, if both engines are equipped with a specific accessory gearbox (AGB) starter gearshaft or transfer gearbox (TGB) input bevel gear, and daily checks of the AGB/TGB magnetic chip detector. This amendment is prompted by further investigation that has revealed that certain TGB output bevel gears and AGB intermediate gear assemblies on CFM56-3, -3B, and -3C series engines, and AGB gearshaft cluster spur assemblies on CFM56-5, -5B, and -5C series engines could also be affected. The actions specified by this AD are intended to prevent inflight engine shutdowns due to an AGB starter gearshaft, TGB input bevel gear, TGB output bevel gear, AGB gearshaft cluster spur assembly or AGB intermediate gear assembly failure.

Final rule; request for comments.

98-10-11 CFM International: Amendment 39-10523. Docket No. 97-ANE-54-AD. Supersedes telegraphic AD T97-25-51.
Applicability: CFM International (CFMI) CFM56-3, -3B, and -3C series turbofan engines, having any of the engine serial numbers (ESNs) identified in Table 1 of CFMI CFM56-3/-3B/-3C Service Bulletin (SB) No. 72-863, Revision 1, dated November 18, 1997, Table 1 of CFMI CFM56-3/-3B/-3C SB No. 72-867, dated November 28, 1997, or Table 1 of CFMI CFM56-3/-3B/-3C SB No. 72-873, Revision 1, dated February 5, 1998; CFM56-5 series turbofan engines, having any of the ESNs identified in Table 1 of CFMI CFM56-5 SB No. 72-523, Revision 1, dated January 30, 1998; CFM56-5B series turbofan engines, having any of the ESNs identified in Table 1 of CFMI CFM56-5B SB No. 72-211, Revision 1, dated January 29, 1998; and CFM56-5C series turbofan engines, having any of the ESNs identified in Table 1 of CFMI CFM56-5C SB No. 72-350, Revision 1, dated January 30, 1998. These engines are installed on but not limited to Boeing 737 series, and Airbus Industrie A319, A320, A321, and A340 series aircraft.
Note 1: This airworthiness directive (AD) applies to each engine identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For engines that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (i) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.
Compliance: Required as indicated, unless accomplished previously.
To prevent inflight engine shutdowns due to an accessory gearbox (AGB) starter gearshaft, transfer gearbox (TGB) input bevel gear, TGB output bevel gear, AGB gearshaft cluster spur assembly or AGB intermediate gear assembly failure, accomplish the following:
(a) For twin engine aircraft that are equipped with both engines identified by ESN in Table 1 of the applicable SB noted in the Applicability paragraph of this AD, prior to further flight, accomplish the following:
(1) Remove one of the engines, and replace with an engine not identified by ESN in Table 1 of the applicable SB noted in the Applicability paragraph of this AD; or
(2) On one of the engines, accomplish the following as applicable:
(i) For CFM56-3, -3B, and -3C series engines:
(A) Replace the AGB starter gearshaft with a serviceable part, as defined in paragraph (h) of this AD, in accordance with CFMI CFM56-3/-3B/-3C SB No. 72-863, Revision 1, dated November 18, 1997,
(B) Replace the TGB assembly with a serviceable part, as defined in paragraph (h) of this AD, in accordance with CFMI CFM56-3/-3B/-3C SB No. 72-865, dated November 18, 1997; or, replace the TGB input bevel gear and/or output bevel gear, as applicable, with a serviceable part in accordance with CFMI CFM56-3/-3B/-3C SB No. 72-867, dated November 28, 1997,
(C) Replace the AGB intermediate gear assembly with a serviceable part, as defined in paragraph (h) of this AD, in accordance with CFMI CFM56-3/-3B/-3C SB No. 72-873, Revision 1, dated February 5, 1998.
(ii) For CFM56-5 series engines, replace the gearshaft cluster spur assembly with a serviceable part, as defined in paragraph (h) of this AD, in accordance with CFMI CFM56-5 SB No. 72-523, Revision 1, dated January 30, 1998.
(iii) For CFM56-5B series engines, replace the gearshaft cluster spur assembly with a serviceable part, as defined in paragraph (h) of this AD, in accordance with CFMI CFM56-5B SB No. 72-211, Revision 1, dated January 29, 1998.
(b) For four engine aircraft that are equipped with morethan one engine identified by ESN in Table 1 of CFMI CFM56-5C SB No. 72-350, Revision 1, dated January 30, 1998, prior to further flight, accomplish the following:
(1) Remove at least all but one affected engine from the aircraft, and replace with serviceable engines not identified by ESN in Table 1 of CFMI CFM56-5C SB No. 72-350, Revision 1, dated January 30, 1998; or
(2) Replace the gearshaft cluster spur assembly with a serviceable part, as defined in paragraph (h) of this AD, in accordance with CFMI CFM56-5C SB No. 72-350, Revision 1, dated January 30, 1998, on at least all but one affected engine.
(c) For CFM56-3, -3B, and -3C series engines identified by ESN in Table 1 of CFMI CFM56-3/-3B/-3C SB No. 72-863, Revision 1, dated November 18, 1997, or CFMI CFM56-3/-3B/-3C SB No. 72-867, dated November 28, 1997, prior to further flight, and thereafter once per calendar day, perform checks of the AGB/TGB magnetic chip detector in accordance with CFMI CFM56-3/-3B/-3C Alert Service Bulletin (ASB) No. 72-A861, Revision 3, dated December 3, 1997. If magnetic particles are found to be abnormal in accordance with CFMI CFM56-3/-3B/-3C ASB No. 72-A861, Revision 3, dated December 3, 1997, prior to further flight, accomplish the following as applicable:
(1) For engines identified by ESN in Table 1 of CFMI CFM56-3/-3B/-3C SB No. 72-863, Revision 1, dated November 18, 1997, remove the AGB starter gearshaft, and replace with a serviceable part, as defined in paragraph (h) of this AD, in accordance with CFMI CFM56-3/-3B/-3C SB No. 72-863, Revision 1, dated November 18, 1997.
(2) For engines identified by ESN in Table 1 of CFMI CFM56-3/-3B/-3C SB No. 72-867, dated November 28, 1997, remove the TGB assembly and replace with a serviceable part, as defined in paragraph (h) of this AD, in accordance with CFMI CFM56-3/-3B/-3C SB No. 72-865, dated November 18, 1997; or, remove the TGB input bevel gear and/or TGB output bevel gear, as applicable, and replace with serviceable parts, as defined in paragraph (h) of this AD, in accordance with CFMI CFM56-3/-3B/-3C SB No. 72-867, dated November 28, 1997.
(d) For CFM56-3, -3B, and -3C series engines identified by ESN in Table 1 of CFMI CFM56-3/-3B/-3C SB No. 72-863, Revision 1, dated November 18, 1997, remove the AGB starter gearshaft within 30 days after the effective date of this AD, and replace with a serviceable part, as defined in paragraph (h) of this AD, in accordance with CFMI CFM56-3/-3B/-3C SB No. 72-863, Revision 1, dated November 18, 1997. Installation of a serviceable AGB starter gearshaft, as defined in paragraph (h) of this AD, and compliance with paragraph (e) of this AD, if applicable, constitutes terminating action to the daily AGB/TGB magnetic chip detector checks required by paragraph (c) of this AD.
(e) For CFM56-3, -3B, and -3C series engines identified by ESN in Table 1 of CFMI CFM56-3/-3B/-3C SB No. 72-867, dated November 28, 1997, remove the TGB assembly in accordance withCFMI CFM56-3/-3B/-3C SB No. 72-865, dated November 18, 1997; or, remove the TGB input bevel gear and/or output bevel gear, as applicable, within 30 days after the effective date of this AD, and replace with serviceable parts, as defined in paragraph (h) of this AD, in accordance with CFMI CFM56-3/-3B/-3C SB No. 72-867, dated November 28, 1997. Installation of a serviceable TGB assembly, or TGB input bevel gear and/or TGB output bevel gear, as defined in paragraph (h) of this AD, and compliance with paragraph (d) of this AD if applicable, constitutes terminating action to the daily AGB/TGB magnetic chip detector checks required by paragraph (c) of this AD.
(f) For CFM56-3, -3B, and -3C series engines identified by ESN in Table 1 of CFMI CFM56-3/-3B/-3C SB No. 72-873, Revision 1, dated February 5, 1998, remove the AGB intermediate gear assembly within 30 days after the effective date of this AD, and replace with a serviceable part, as defined in paragraph (h) of this AD, in accordance with CFMI CFM56-3/-3B/-3C SB No. 72-873, Revision 1, dated February 5, 1998.
(g) For CFM56-5, -5B, and -5C series engines identified by ESN in Table 1 of CFMI CFM56-5 SB No. 72-523, Revision 1, dated January 30, 1998, CFMI CFM56-5B SB No. 72-211, Revision 1, dated January 29, 1998, or CFMI CFM56-5C SB No. 72-350, Revision 1, dated January 30, 1998, remove the gearshaft cluster spur assembly within 30 days after the effective date of this AD, and replace with a serviceable part, as defined in paragraph (h) of this AD, in accordance with CFMI CFM56-5 SB No. 72-523, Revision 1, dated January 30, 1998, CFMI CFM56-5B SB No. 72-211, Revision 1, dated January 29, 1998, or CFMI CFM56-5C SB No. 72-350, Revision 1, dated January 30, 1998, as applicable.
(h) For the purposes of this AD, a serviceable part is defined as an AGB starter gearshaft, Part Number (P/N) 335-302-503-0, a TGB assembly, P/N 335-300-012-0, a TGB input bevel gear, P/N 335-321-008-0, a TGB output bevel gear, P/N 335-322-405-0, AGB gearshaft cluster spur assembly, P/N 335-302-503-0, or an AGB intermediate gear assembly, P/N 335-303-202-0, not identified by part serial number in Table 1 of the applicable SB noted in the Applicability Section of this AD.
(i) An alternative method of compliance or adjustment of the initial compliance time that provides an acceptable level of safety may be used if approved by the Manager, Engine Certification Office. The request should be forwarded through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Engine Certification Office.
Note 2: Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the Engine Certification Office.
(j) The actions required by this AD shall be accomplished in accordance with the following CFMI service documents:

Document No.
Page
Revision
Date
CFM56-3/-3B/-3C ASB No. 72-A8611-10
3
December 3, 1997
Total Pages: 10.

CFM56-3/-3B/-3C SB No. 72-863
1-39
1
November 18, 1997
Total Pages: 39.

CFM56-3/-3B/-3C SB No. 72-865
1-8
Original
November 18, 1997
Total Pages: 8.

CFM56-3/-3B/-3C SB No. 72-867
1-11
Original
November 28, 1997
Total Pages: 11.

CFM56-3/-3B/-3C SB No. 72-873
1-21
1
February 5, 1998
Total Pages: 21.

CFM56-5 SB No. 72-523
1-33
1
January 30, 1998
Total Pages: 33.

CFM56-5B SB No. 72-211
1-28
1
January 29, 1998
Total Pages: 28.

CFM56-5C SB No. 72-350
1-28
1
January 30, 1998
Total Pages: 28.

This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from CFM International, Technical Publications Department, 1 Neumann Way, Cincinnati, OH 45215; telephone (513) 552-2981, fax (513) 552-2816. Copies may be inspected at the FAA, New England Region, Office of the Regional Counsel, 12 New England Executive Park, Burlington, MA; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.
(k) This amendment supersedes telegraphic AD T97-25-51, issued December 4, 1997.
(l) This amendment becomes effective on June 3, 1998.

On December 4, 1997, the Federal Aviation Administration (FAA) issued telegraphic airworthiness directive (AD) T97-25-51, applicable to CFM International (CFMI) CFM56-3, -3B, and -3C series turbofan series engines, which requires removal of one engine from an aircraft, and replacement with a serviceable engine or replacement of parts, if both engines are equipped with a specific accessory gearbox (AGB) starter gearshaft or transfer gearbox (TGB) input bevel gear. In addition, that telegraphic AD requires daily checks of the AGB/TGB magnetic chip detector on engines identified by engine serial number (ESN) in the applicability section of that telegraphic AD until installation of a serviceable starter gearshaft or input bevel gear. That action was prompted by reports of three inflight engine shutdowns due to AGB starter gearshaft failures, and reports of four findings of TGB input bevel gear cracks that were detected during inspections. All seven reports occurred on low time newly delivered CFM56-3 series turbofan engines. The engines involved in these reports had time in service since new ranging from 213 to 500 hours, and cycles in service since new ranging from 153 to 229.
Preliminary investigation results indicate that the root cause of the AGB starter gearshaft failure and TGB input bevel gear cracks may stem from the improper cleaning procedure prior to the black oxide process during manufacture that causes residual stresses around the welding areas that could lead to a crack. That condition, if not corrected, could result in inflight engine shutdowns due to an AGB starter gearshaft or TGB input bevel gear failure.
Since the issuance of that telegraphic AD, the FAA has determined that certain TGB output bevel gears and AGB intermediate gear assemblies on CFM56-3, -3B, and -3C series engines, and AGB gearshaft cluster spur assemblies on CFM56-5, -5B, and -5C series engines could also be affected. There are 44 total AGB starter gearshafts, 41 total TGB input bevel gears, 33 total TGB output bevel gears, 60 total AGB gearshaft cluster spur assemblies, and 37 AGB intermediate gear assemblies that may be affected. Therefore, this expands the applicability of the AD to include those engines with these parts installed.
The FAA has reviewed and approved the technical contents of CFMI CFM56-3/-3B/-3C Alert Service Bulletin (ASB) No. 72-A861, Revision 3, dated December 3, 1997, that describes procedures for AGB/TGB magnetic chip detector inspections. In addition, the FAA has reviewed and approved the technical contents of CFMI CFM56-3/-3B/-3C Service Bulletin (SB) No. 72-863, Revision 1, dated November 18, 1997; CFMI CFM56-3/-3B/-3C SB No. 72-865, dated November 18, 1997; CFMI CFM56-3/-3B/-3C SB No. 72-867, dated November 28, 1997; CFMI CFM56-3/-3B/-3C SB No. 72-873 Revision 1, dated February 5, 1998; CFMI CFM56-5 SB No. 72-523, Revision 1, dated January 30, 1998; CFMI CFM56-5B SB No. 72-211, Revision 1, datedJanuary 29, 1998; and CFMI CFM56-5C SB No. 72-350, Revision 1, dated January 30, 1998. These SBs describe procedures for removal and replacement of the AGB starter gearshaft, TGB assembly, TGB input bevel gear, TGB output bevel gear, AGB gearshaft cluster spur assembly or AGB intermediate gear assembly.
Since an unsafe condition has been identified that is likely to exist or develop on other engines of this same type design, this AD supersedes telegraphic AD T97-25-51 to require the removal of one engine on twin engine aircraft, and replacement with a serviceable engine or replacement of parts, if both engines are equipped with a specific AGB starter gearshaft, TGB input bevel gear, TGB output bevel gear, or AGB intermediate gear assembly. This AD also requires the removal of all necessary engines on four engine aircraft, and replacement with a serviceable engine or replacement of the AGB gearshaft cluster spur assembly, if more than one affected engine is installed on the aircraft. In addition, this AD requires daily checks of the AGB/TGB magnetic chip detector on CFM56-3, -3B, and -3C series engines identified in Table 1 of CFMI CFM56-3/-3B/-3C SB No. 72-863, Revision 1, dated November 18, 1997, or CFMI CFM56-3/-3B/-3C SB No. 72-867, dated November 28, 1997. If abnormal magnetic particles are found, this AD requires, prior to further flight, installation of a serviceable AGB starter gearshaft, TGB assembly, TGB input bevel gear, or TGB output bevel gear. This AD also requires, within 30 days after the effective date of this AD, installation of a serviceable AGB starter gearshaft, serviceable TGB assembly, serviceable TGB input bevel gear, serviceable TGB output bevel gear, serviceable AGB gearshaft cluster spur assembly or an AGB intermediate gear assembly, as applicable. Installation of a serviceable AGB starter gearshaft, TGB assembly, TGB input bevel gear or output bevel gear, as applicable, constitutes terminating action to the daily AGB/TGB magneticchip detector inspections. The calendar end-date was based upon FAA risk assessment and parts availability. The actions are required to be accomplished in accordance with the service documents described previously.
Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days. Comments Invited
Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications should identify the Rules Docket number and be submitted in triplicate to the address specified under the caption "ADDRESSES." All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.
Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket Number 97-ANE-54-AD." The postcard will be date stamped and returned to the commenter.
The regulations adopted herein will not have substantial direct effects 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. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.
The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and is not a "significant regulatory action" under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES." List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows: PART 39 - AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new airworthiness directive: