[Docket No. FAA-2015-0277; Directorate Identifier 2015-NE-05-AD; Amendment 

39-18262; AD 2015-18-04] 

RIN 2120-AA64 

Airworthiness Directives; CFM International S.A. Turbofan Engines AGENCY: Federal Aviation Administration (FAA), DOT. 

ACTION: Final rule. 

SUMMARY: We are adopting a new airworthiness directive (AD) for certain CFM 

International S.A. (CFM) CFM56-7B and CFM56-3 turbofan engines. This AD was 

prompted by a report of an uncommanded in-flight shutdown (IFSD) on a CFM CFM56-

7B engine following rupture of the 73-tooth gearshaft located in the engine accessory 

gearbox (AGB). This AD requires AGE/transfer gearbox (TGB) magnetic chip detector 

(MCD) inspection of the affected gearshafts until removal. We are issuing this AD to 

prevent failure of certain engine AGB gearshafts, which could lead to failure of one or 

more engines, loss of thrust control, and damage to the airplane. 

DATES: This AD is effective [INSERT DATE 35 DAYS AFTER DATE OF 

PUBLICATION IN THE FEDERAL REGISTER]. 

The Director of the Federal Register approved the incorporation by reference of a 

certain publication listed in this AD as of [INSERT DATE 35 DAYS AFTER DATE OF 

PUBLICATION IN THE FEDERAL REGISTER]. 

ADDRESSES: For service information identified in this AD, contact CFM International 

Inc., Aviation Operations Center, 1 Neumann Way, MID Room 285, Cincinnati, OH 

45125; phone: 877-432-3272; fax: 877-432-3329; email: aviation.fleetsupport@ge.com. 

You may view this service information at the FAA, Engine & Propeller Directorate, 12 
You may examine the AD docket on the Internet at http://www.regulations.gov by 

searching for and locating Docket No. FAA-2015-0277; or in person at the Docket 

Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal 

holidays. The AD docket contains this AD, the regulatory evaluation, any comments 

received, and other information. The address for the Docket Office (phone: 

800-647-5527) is Document Management Facility, U.S. Department of Transportation, 

Docket Operations, M-30, West Building Ground Floor, Room WI2-140, 1200 New 

Jersey Avenue SE., Washington, DC 20590. 

FOR FURTHER INFORMATION CONTACT: Kyle Gustafson, Aerospace Engineer, 

Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England 

Executive Park, Burlington, MA 01803; phone: 781-238-7183; fax: 781-238-7199; email: 

kyle.gustafson@faa.gov. 

SUPPLEMENTARY INFORMATION: 

Discussion 

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by 

adding an AD that would apply to certain CFM CFM56-7B series turbofan engines. The 

NPRM published in the Federal Register on May 1, 2015 (80 FR 24856). The NPRM was 

prompted by a report of an uncommanded IFSD on a CFM CFM56-7B engine following 

rupture of the 73-tooth gearshaft located in the engine AGB. The NPRJ\t1 proposed to 

require MCD inspection of the affected gearshafts until removal. 

2 
Request to Add CFM56-3 Engines to Applicability 

CFM requested that we add CFM56-3 engines to this AD, as the CFM56-3 

engines share the same 73-tooth and 41-tooth gearshafts as the CFM56-7B engines. 

We agree. We revised the applicability of this AD by adding CFM56-3 engines. 

Request to Clarify Discussion of IFSDs 

CFM commented that the NPRM (80 FR 24856, May I, 2015) incorrectly 

indicated that multiple instances ofuncornrnanded IFSDs occurred on CFM56-7B 

engines follov..ring rupture of the 73-tooth gearsha:ft when only one IFSD actually 

occurred. CFM requested that this AD be revised to reflect that only one IFSD occurred 

following rupture of the 73-tooth gearsha:ft. 

We agree. We revised the Summary, Discussion, and Unsafe Condition sections 

of this final rule to reflect the occurrence of one IFSD following rupture of the 73-tooth 

gearshaft in the CFM56-7B's AGB. 

Request to Clarify Inspection Requirement 

CFM commented that the NPRM (80 FR 24856, May I, 2015) did not clearly 

specify that the MCD inspection is of the AGB/TGB. 

We agree. We revised the Summary and the Compliance sections of this final rule 

to reflect that the required inspection is an "AGB/TGB MCD inspection." 

Request to Clarify Relevant Service Information 

CFM requested that we specify in the Relevant Service Information section of the 

NPRM (80 FR 24856, May l, 2015) that the referenced service bulletins (SBs) describe 

3 
http://wv.rw.regulations.gov by searching for and locating Docket No. FAA-2015-0277. 

We did not change this AD. 

Request to Clarify Proposed AD Requirements 

CFM commented that the Proposed AD Requirements section should be revised 

to be consistent with the compliance and mandatory terminating action paragraphs in this 

AD. 

We disagree. This AD incorporates changes produced as a result of the comments 

received, as permitted by the Administrative Procedures Act (APA) (Public Law 79-404, 

5 U.S.C. § 551, et. seq.). To take the action the comrnenter suggests would be contrary to 

the APA. We did not change this AD. 

Request to Allow Use of Later Revisions to SBs 

CFM requested that we include a provision in this AD to allow for use of later 

revisions to CFM SB No. CFM56-7B SIB 72-0964, Revision I, dated December 15, 

2014, and SB No. CFM56-7B SIB 72-0965, dated December 16,2014. 

We disagree. We do not know the content of future revisions ofSBs and, 

therefore, cannot approve them before publication. We did not change this AD. 

Request to Revise Description of Laboratory Analysis 

CFM requested we change the wording in the Compliance section of this AD 

from "particles lab analysis" to "laboratory analysis." 

We agree. The term "laboratory analysis" is more accurate. We revised the term 

"particles lab analysis" to read "laboratory analysis" in the Compliance section of this 

AD. 

4 
We disagree. Operators have access to CFM SB No. CFM56-7B SIB 72-0964, 

Revision 1, dated December 15,2014, in the AD docket on the Internet at 

http://www.regulations.gov by searching for and locating Docket No. FAA-2015-0277, 

or by requesting the SB from CFM. We did not change this AD. 

Request to Limit Applicability by Engine Serial Number 

Sun Country Airlines requested that the Applicability of this AD be limited to 

CFM56-7B engines with engine SINs listed in Appendix A of CFM SB No. CFM56-7B 

SIB 72-0964 and CFM56-7B engines that have the 73-tooth gearshafts listed in Appendix 

B ofCFM SB No. CFM56-7B SIB 72-0964 installed post-production. Sun Country 

Airlines noted that the applicability of the NPRM (80 FR 24856, May 1, 2015) could be 

misconstrued to mean to include all CFM56-7B engines unless it is proven that they do 

not have the affected 73-tooth or 41-toth gearshafts. 

We disagree. CFM identified the affected population of gearshafts by gearshaft 

SIN and by the engine SIN on which it was installed. However, an affected gearshaft may 

now be installed on an engine with an SIN not listed in Appendix A. To address the latter 

population, those engines with a gearshaft that has been installed on an unknown engine, 

we identified the affected population of73-tooth and 41-tooth gearshafts by gearshaft 

part number and SIN. We did not change this AD. 

Request to Clarify that Applicability is by Gearshaft Serial Number 

Delta Air Lines (Delta) requested that we clarify that the applicability of the AD 

is by gears haft S/N rather than by engine SIN. 

5 
CFM56-7B S/B 72-0964, Revision I, dated December 15, 2014." 

Request to Verify Affected Gearshafts Have Been Removed From Service and 

Reduce the Scope of Applicability 

Delta requested that we verify which gearshafts have been removed from service 

per the proposed requirements of the NPRM (80 FR 24856, May I, 2015). Delta further 

asked that we reduce the applicability to only those affected gearshafts that remain in 

service. 

We disagree. This AD will ensure that all affected gearshafts are removed from 

service and that gearshafts already removed from service are not returned to service. We 

did not change this AD. 

Support for the NPRM 

The Boeing Company and an anonymous commenter expressed support for the 

NPRM (80 FR 24856, May 1, 2015) as proposed. 

Conclusion 

We reviewed the relevant data, considered the comments received, and 

determined that air safety and the public interest require adopting this AD with the 

changes described previously. 

We also determined that these changes will not increase the economic burden on 

any operator or increase the scope of this AD. 

Related Service Information under 1 CFR Part 51 

We reviewed CFM SB No. CFM56-7B SIB 72-0964, Revision I, dated December 

15, 2014. The service information describes procedures for removal of affected 73-tooth 

6 
We estimate that this AD will affect about 67 engines installed on airplanes of 

U.S. registry. We also estimate that it will take about 1 hour per engine to do the 

inspection and 8 hours per engine to replace each affected gearshaft. We estimate thirtysix 73-tooth gearshafts and forty 41-tooth gearshafts will need replacement at a cost of 

$12,480 and $7,680 per part, respectively. The average labor rate is $85 per hour. Based 

on these figures, we estimate the cost of this AD on U.S. operators to be $813,855. 

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. 

Regulatory Findings 

This AD will not have federalism implications Wlder Executive Order 13132. This 

AD will not have a substantial direct effect on the States, on the relationship between the 

7 
(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 to the extent that it justifies 

making a regulatory distinction, and 

( 4) Will not have a significant economic impact, positive or negative, on a 

substantial number of small entities tmder the criteria of the Regulatory Flexibility Act. 

List of Subjects in 14 CFR Part 39 

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

Adoption of the Amendment 

Accordingly, under the authority delegated to me by the Administrator, the FAA 

amends 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. The FAA amends§ 39.13 by adding the following new airworthiness directive 

(AD): 

2015-18-04 CFM International S.A.: Amendment 39-18262; Docket 

No. FAA-2015-0277; Directorate Identifier 2015-NE-05-AD. 

(a) Effective Date 

This AD is effective [INSERT DATE 35 DAYS AFTER DATE OF 

PUBLICATION IN THE FEDERAL REGISTER]. 

8 
engines with a 73-tooth or 41-tooth gearshaft installed in the accessory gearbox (AGB), 

that has a gearshaft serial number in Appendix A or Appendix B of CFM Service Bulletin 

(SB) No. CFM56-7B SIB 72-0964, Revision I, dated December 15, 2014. 

(d) Unsafe Condition 

This AD was prompted by a report of an uncommanded in-flight shutdown on a 

CFM CFM56-7B engine following rupture of the 73-tooth gearshaft located in the engine 

AGE. We are issuing this AD to prevent failure of certain AGB gearshafts, which could 

lead to failure of one or more engines, loss of thrust control, and damage to the airplane. 

(e) Compliance 

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

(1) Initial AGE/Transfer Gearbox (TGB)/Magnetic Chip Detector (MCD) 

Inspection and Analysis 

(i) For affected 73-tooth gearshafts, perform an AGB/TGB MCD inspection 

within 250 flight hours (FHs) since last inspection, within 25 FHs from the effective date 

of this AD, or when the gearshaft accumulates 3,000 FI-ls since new, whichever comes 

later. 

(ii) For affected 41-tooth gearshafts, perform an AGB/TGB MCD inspection 

within 250 FHs since last inspection, within 25 FHs from the effective date of this AD, or 

when the gearshaft accumulates 6,000 FHs since new, whichever comes later. 

(iii) If any magnetic particles, including fuzz, are seen, determine with laboratory 

analysis if the particles are 73-tooth or 41-tooth gearshaft material. 

9 
laboratory analysis within every 500 FHs since the last AGB/TGB MCD inspection until 

affected gearshaft is removed. 

(ii) For affected 41-tooth gearshafts, perform an AGB/TGB MCD inspection and 

laboratory analysis within every 500 FHs since the last AGB/TGB MCD inspection until 

affected gearshaft is removed. 

(iii) If any magnetic particles, including fuzz, are seen, determine with laboratory 

analysis if the particles are 73-tooth or 41-tooth gearshaft materiaL 

(iv) If the particles are 73-tooth or 41-tooth gearshaft material, remove the 

affected gearshaft(s) within 75 FHs since the AGB/TGB MCD inspection. 

(f) Mandatory Terminating Action 

(1) Remove the affected 73-tooth gearshaft prior to the gearshaft accumulating 

6,000 FHs since new or within 50 FHs after the effective date of this AD, whichever 

comes later. 

(2) Remove the affected 41-tooth gearshaft prior to the gearshaft accumulating 

9,000 FHs since new or within 50 FHs after the effective date of this AD, whichever 

comes later. 

(g) Installation Prohibition 

After the effective date of this AD, do not install an affected gearshaft into an 

AGB, 

10 
(i) Related Information 

For more information about this AD, contact Kyle Gustafson, Aerospace 

Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New 

England Executive Park, Burlington, MA 01803; phone: 781-238-7183; fax: 

781-238-7199; email: kyle.gustafson@faa.gov. 

(j) 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. 

(2) You must use this service information as applicable to do the actions required 

by this AD, tmless the AD specifies otherwise. 

(3) The following service information was approved for IBR on [INSERT DATE 

35 DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER]. 

(i) CFM International Service Bulletin No. CFM56-7B S/B 72-0964, Revision 1, 

dated December 15,2014. 

(ii) Reserved. (4) For CFM service information identified in this AD, contact CFM International 

Inc., Aviation Operations Center, 1 Neumann Way, MID Room 285, Cincinnati, OH 

45125; phone: 877-432-3272; fax: 877-432-3329; email: aviation.fleetsupport@ge.com. 

(5) You may view this service information at FAA, Engine & Propeller 

Directorate, 12 New England Executive Park, Burlington, MA. For information on the 

availability of this material at the FAA, call 781-238-7125. 

11 
Issued in Burlington, Massachusetts, on August 28,2015. 

Ann C. Mollica, 

Acting Directorate Manager, Engine & Propeller Directorate, 

Aircraft Certification Service. 

12