[4910-13-P] 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA-2013-0447; Directorate Identifier 2013-NE-17-AD; Amendment 

39-17536; AD 2013-15-20] 

RIN 2120-AA64 

Airworthiness Directives; General Electric Company Turbofan Engines 

AGENCY: Federal Aviation Administration (FAA), DOT. 

ACTION: Final rule; request for comments.

SUMMARY: We are superseding emergency airworthiness directive (AD) 2013-14-51 

for General Electric Company (GE) GE90-110B1 and GE90-115B turbofan engines with 

affected transfer gearbox assembly (TGB) radial gearshafts installed. AD 2013-14-51 

was sent previously to all known U.S. owners and operators of GE90-110B1 and GE90-

115B turbofan engines. AD 2013-14-51 prohibited operation of an airplane if more than 

one installed engine has an affected TGB radial gearshaft. This AD contains the same 

prohibition as AD 2013-14-51 and also prohibits operation of any airplane 60 days after 

the effective date of this new AD if any installed engine has an affected TGB radial 

gearshaft. This new AD also revises the applicability by adding GE90-76B, GE90-77B, 

GE90-85B, GE90-90B, GE90-94B, and GE90-113B turbofan engine models and adds a 

mandatory terminating action. This new AD was prompted by reports of three failures of 

TGB radial gearshafts which resulted in in-flight shutdowns (IFSDs). We are issuing this 

new AD to prevent failure of the TGB radial gearshaft, which could result in IFSD of one 

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

DATES: This AD is effective [INSERT DATE 15 DAYS AFTER DATE OF 

PUBLICATION IN THE FEDERAL REGISTER]. 
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We must receive any comments on this AD by [INSERT DATE 45 DAYS 

AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER]. 

ADDRESSES: You may send comments by any of the following methods: 

• Federal eRulemaking Portal: Go to http://www.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: U.S. Department of Transportation, Docket Operations, M-30, 

West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE., 

Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, except 

Federal holidays. 

For service information identified in this AD, contact General Electric Company, 

One Neumann Way, Room 285, Cincinnati, OH; phone: 513-552-3272; email: 

geae.aoc@ge.com. You may view this service information at the 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. 

Examining the AD Docket 

You may examine the AD docket on the Internet at http://www.regulations.gov; 

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 street address for the 

Docket Office (phone: 800-647-5527) is in the ADDRESSES section. Comments will be 

available in the AD docket shortly after receipt. 
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FOR FURTHER INFORMATION CONTACT: Carlos Fernandes, Aerospace 

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

England Executive Park, Burlington, MA 01803; phone: 781-238-7189; fax: 781-238-

7199; email: carlos.fernandes@faa.gov. 

SUPPLEMENTARY INFORMATION: 

Discussion 

On May 16, 2013, we issued emergency AD 2013-10-52 (issued on June 16, 

2013, as a Final Rule, Request for Comments (78 FR 38195, June 26, 2013)), which was 

immediately effective to owners and operators of GE GE90-110B1 and GE90-115B 

turbofan engines. That AD resulted from reports of two failures of TGB radial gearshafts 

that resulted in IFSDs. That AD prohibited operation of an airplane with affected TGBs 

installed on both engines. 

On July 12, 2013, we issued emergency AD 2013-14-51, superseding AD 2013-

10-52 (78 FR 38195, June 26, 2013). AD 2013-14-51 also prohibits operation of an 

airplane with affected TGB radial gearshafts installed on both engines. AD 2013-14-51 

resulted from a report of an additional failure of a TGB radial gearshaft, outside the 

population identified in AD 2013-10-52. We issued ADs 2013-10-52 and 2013-14-51 to 

prevent failure and separation of the TGB radial gearshaft, which could result in IFSD of 

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

Actions Since AD 2013-14-51 was Issued 

Since we issued emergency AD 2013-14-51, dated July 12, 2013, we determined 

that airplanes with an installed engine with an affected TGB radial gearshaft should not 

be allowed to operate more than 60 days after the effective date of this new AD. We also 

revised the Applicability of this new AD since we determined that the affected TGB 

radial gearshafts are installed on additional GE90 engine models besides the GE90-
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110B1 and GE90-115B. We also determined the need to add a mandatory terminating 

action. 

Relevant Service Information 

We reviewed GE GE90-100 Series Alert Service Bulletin (ASB) No. GE90-100 

S/B 72-A0568, dated July 10, 2013; GE GE90-100 Series Service Bulletin (SB) No. 

GE90-100 S/B 72-0569, Revision 0, dated July 19, 2013; and GE GE90 SB No. GE90 

S/B 72-1091, Revision 0, dated June 11, 2013, which provide additional information 

regarding the affected TGB radial gearshafts. We also reviewed GE GE90-100 Series SB 

No. GE90-100 S/B 72-0563, Revision 0, dated June 21, 2013, and Revision 1, dated July 

10, 2013; and GE GE90 SB No. GE90 S/B 72-1066, Revision 0, dated June 21, 2013; 

which provide information regarding the mandatory terminating action. 

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 prohibits operation of an airplane with affected TGB radial gearshafts 

installed on both engines after the effective date of this AD. This AD also prohibits 

operation of an airplane with affected TGB radial gearshafts installed on any engine 60 

days after the effective date of this AD. This AD also adds a mandatory terminating 

action, namely, to install a TGB radial gearshaft that is eligible for installation. 

FAA’s Justification and Determination of the Effective Date 

An unsafe condition exists that requires the immediate adoption of this AD. The 

FAA has found that the risk to the flying public justifies waiving notice and comment 

prior to adoption of this rule because of the before further flight compliance time. 

Therefore, we find that notice and opportunity for prior public comment are 
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impracticable and 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 AD. Send your comments to an address listed under the ADDRESSES section. 

Include the docket number FAA-2013-0447 and directorate identifier 2013-NE-17-AD at 

the beginning of your comments. We specifically invite comments on the overall 

regulatory, economic, environmental, and energy aspects of this AD. We will consider all 

comments received by the closing date and may amend this AD 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 AD. 

Costs of Compliance 

We estimate that this AD will affect about 16 GE90 engines installed on airplanes 

of U.S. registry. We also estimate that it will take about eight hours per engine to replace 

the TGB radial gearshaft. The average labor rate is $85 per hour. The cost of this part is 

about $16,700. Based on these figures, we estimate the total cost of this AD to U.S. 

operators to be $278,080. 

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. 
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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 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 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 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. 

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: 
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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: 

a. Removing AD 2013-10-52 (78 FR 38195, June 26, 2013); and 

b. Adding the following new AD: 

2013-15-20: Amendment 39-17536; Docket No. FAA-2013-0447; Directorate 

Identifier 2013-NE-17-AD. 

(a) Effective Date 

This AD is effective [INSERT DATE 15 DAYS AFTER DATE OF 

PUBLICATION IN THE FEDERAL REGISTER]. 

(b) Affected ADs 

This AD supersedes Emergency AD 2013-14-51, Directorate ID 2013-NE-17-

AD, dated July 12, 2013. This AD also removes AD 2013-10-52 (78 FR 38195, June 26, 

2013) from the Code of Federal Regulations. 

(c) Applicability 

General Electric Company (GE) GE90-76B, GE90-77B, GE90-85B, GE90-90B, 

GE90-94B, GE90-110B1, GE90-113B and GE90-115B turbofan engines with a transfer 

gearbox assembly (TGB) radial gearshaft, part number (P/N) 1995M24P02, serial 

number (S/N) listed in Figure 1 to paragraph (c) of this AD, installed. 

Figure 1 to Paragraph (c) – TGB Radial Gearshaft P/N 1995M24P02 S/N’s 

FIA0KCYG FIA0JETA FIA0H0VJ FIA0HL0C 

FIA0K63F FIA0J7V2 FIA0K62R FIA0HLY9 

FIA0K3A3 FIA0KCYM FIA0K63C FIA0HL0E 

FIA0JVRE FIA0JJ6E FIA0K89H FIA0HL0F 

FIA0H0VM FIA0JNJH FIA0KCYK FIA0HL0G 

FIA0K3A4 FIA0K62W FIA0K3A5 FIA0HLY7 

FIA0K62T FIA0K89P FIA0HWKA FIA0HJTE 
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FIA0JJ53 FIA0JJ57 FIA0KCYR FIA0HJTJ 

FIA0K89W FIA0JJ56 FIA0HWKE FIA0HJTG 

FIA0KCW8 FIA0KH9Y FIA0J7WH FIA0HJTC 

FIA0K3A6 FIA0KCYP FIA0JER9 FIA0HJTF 

FIA0HY8C FIA0JJ55 FIA0JNJJ FIA0HJTH 

FIA0K3AP FIA0KH9G FIA0JVRR FIA0HJTA 

FIA0J7WG FIA0KH9H FIA0JNJM FIA0HJR9 

FIA0JVRL FIA0KH9K FIA0KH9R FIA0HWJ7 

FIA0J7V1 FIA0KH9C FIA0KH9P FIA0HY76 

FIA0JVRM FIA0K63H FIA0K89C FIA0HY8F 

FIA0K3AV FIA0K63M FIA0JVRH FIA0H0VK 

FIA0J7V8 FIA0K62Y FIA0K89L FIA0J7VR 

FIA0J7WE FIA0JVP9 FIA0JER6 FIA0JJ58 

FIA0K3A2 FIA0K63E FIA0JETH FIA0JJ6C 

FIA0K3A1 FIA0K3AY FIA0H0VC FIA0JNJF 

FIA0K3AN FIA0JVRT FIA0K3AL FIA0JNJK 

FIA0JVRP FIA0HY8E FIA0J7VV FIA0JVRC 

FIA0JJ6F FIA0HY8N FIA0J7VP FIA0J7V4 

FIA0JJ6J FIA0J7V0 FIA0J7V9 FIA0JETF 

FIA0JVRV FIA0J7V3 FIA0HWJ8 FIA0HEG4 

FIA0H0VL FIA0J7V5 FIA0H0VA FIA0HWJ9 

FIA0K89T FIA0HY8H FIA0KCYL FIA0HWJ5 

FIA0K89Y FIA0HEG2 FIA0HY79 FIA0HWJ6 

FIA0JETL FIA0K62V FIA0KH9J FIA0J7VW 

FIA0JER8 FIA0HEGY FIA0HY8G FIA0J7VY 

FIA0J7WC FIA0HWKC FIA0HY8M FIA0J7VT 

FIA0JETE FIA0K3A0 FIA0HY8A FIA0J7WF 

FIA0K3AT FIA0JVRJ FIA0H0VG FIA0J7V6 

FIA0JJ59 FIA0K8AA FIA0K3AR FIA0K89G 

FIA0K3AW FIA0KCYT FIA0JETC FIA0K89K 

FIA0JVRN FIA0KH9T FIA0KH9W FIA0K89R 

FIA0JNH8 FIA0HEG1 FIA0JNJC FIA0KCYJ 

FIA0JETN FIA0HEG3 FIA0K63L FIA0JJ6G 

FIA0HY78 FIA0J7WJ FIA0KCYN FIA0JJ6A 

FIA0HY75 FIA0JER7 FIA0JVRG FIA0HY8K 

FIA0HEG0 FIA0JVRF FIA0HY8L FIA0HLY6 

FIA0KH9E FIA0K63K FIA0HY8J FIA0HLY0 

FIA0KH9F FIA0J7WK FIA0H0VH FIA0HLY1 

FIA0H0T9 FIA0JER5 FIA0H0VF FIA0HLY4 

FIA0HLY3 FIA0JETM 
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(d) Unsafe Condition 

This AD was prompted by reports of three failures of TGB radial gearshafts 

which resulted in in-flight shutdowns (IFSDs). We are issuing this AD to prevent failure 

of the TGB radial gearshaft, which could result in IFSD of one or more engines, loss of 

thrust control, and damage to the airplane. 

(e) Compliance 

(1) Comply with this AD within the compliance times specified, unless already 

done. 

(2) Before further flight after the effective date of this AD, do not operate the 

airplane if more than one installed engine has a TGB radial gearshaft P/N and S/N listed 

in Figure 1 to paragraph (c) of this AD. 

(f) Mandatory Terminating Action 

No later than 60 days after the effective date of this AD, as terminating action to 

the requirements of paragraph (e) of this AD, replace all TGB radial gearshafts identified 

in Figure 1 to paragraph (c) of this AD that are installed on an airplane with TGB radial 

gearshafts that are eligible for installation. 

(g) Prohibition on Operation 

Sixty days after the effective date of this AD, do not operate any airplane that has 

an engine installed that has a TGB radial gearshaft P/N and S/N listed in Figure 1 to 

paragraph (c) of this AD. 

(h) Definition 

For the purposes of this AD, a TGB radial gearshaft eligible for installation is: 

(1) A TGB radial gearshaft P/N and S/N, not listed in this AD or 

(2) A TGB radial gearshaft with an S/N listed in paragraph (c) of this AD with 

part number 1995M24P04, 2205M61P01 or 2205M61P02. 
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(i) Alternative Methods of Compliance (AMOCs) 

The Manager, Engine Certification Office, FAA, may approve AMOCs for this 

AD. Use the procedures in 14 CFR 39.19 to make your request. 

(j) Related Information 

(1) For more information about this AD, contact Carlos Fernandes, Aerospace 

Engineer, Engine Certification Office, FAA, 12 New England Executive Park, 

Burlington, MA 01803; phone: 781-238-7189; fax: 781-238-7199; email: 

carlos.fernandes@faa.gov. 

(2) GE GE90-100 Series Alert Service Bulletin No. GE90-100 S/B 72-A0568, 

Revision 0, dated July 10, 2013; GE GE90-100 Series Service Bulletin (SB) No. GE90-

100 S/B 72-0569, Revision 0, dated July 19, 2013; GE GE90-100 Series SB No. GE90-

100 S/B 72-0563, Revision 0, dated June 21, 2013, and Revision 1, dated July 10, 2013; 

GE GE90 SB No. GE90 S/B 72-1066, Revision 0, dated June 21, 2013; and GE GE90 SB 

No. GE90 S/B 72-1091, Revision 0, dated June 11, 2013, can be obtained from GE using 

the contact information in paragraph (j)(3) of this AD. 

(3) For service information identified in this AD, contact General Electric 

Company, One Neumann Way, Room 285, Cincinnati, OH; phone: 513-552-3272; email: 

geae.aoc@ge.com. 

(4) You may view this service information at the 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. 

(k) Material Incorporated by Reference 

None. 
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Issued in Burlington, Massachusetts, on July 25, 2013. 

Frank P. Paskiewicz, 

Acting Director, 

Aircraft Certification Service.