[Docket No. FAA-2015-6823; Directorate Identifier 2015-NE-38-AD; Amendment 

39-18360; AD 2015-27-01] 

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 adopting a new airworthiness directive (AD) for all General 

Electric Company (GE) GE90-76B, -77B, -85B, -90B, and -94B turbofan engines. This 

AD requires performing an eddy current inspection (ECI) or ultrasonic inspection (USI) 

of the high-pressure compressor (HPC) stage 8-10 spool and removing from service those 

parts that fail inspection. This AD was prompted by an uncontained failure of the HPC 

stage 8-10 spool, leading to an airplane fire. We are issuing this AD to prevent failure of 

the HPC stage 8-10 spool, uncontained rotor release, damage to the engine, and damage 

to the airplane. 

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

PUBLICATION IN THE FEDERAL REGISTER]. 

We must receive comments on this AD by [INSERT DATE 45 DAYS AFTER 

DATE OF PUBLICATION IN THE FEDERAL REGISTER]. 

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 http://www.regulations.gov. Follow the 

instructions for submitting comments. 

• Fax: 202-493-2251. 
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. 

Examining the AD Docket 

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

searching for and locating Docket No. F AA-2015-6823; 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. 

FOR FURTHER INFORMATION CONTACT: John Frost, Aerospace Engineer, 

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

Executive Park, Burlington, MA 01803; phone: 781-238-7756; fax: 781-238-7199; email: 

jolm.frost@faa.gov. 

SUPPLEMENTARY INFORMATION: 

Discussion 

We received a report of an HPC stage 8-10 spool uncontained failure resulting in 

an airplane fire. Ongoing investigations have determined that a crack initiated in the stage 

8 aft web upper face of the HPC 8-10 spool and propagated until spool rupture. The root 

cause of the crack initiation is not yet known. This condition, if not corrected, could 

result in failure of the HPC stage 8-10 spool, uncontained rotor release, damage to the 

2 
24,2015. The SB describes procedures for one-time on-wing USI of the stage 8 web of 

the stage 8-10 spool. We also reviewed the following chapters ofGE GE90 Engine 

Manual, GEK100700, Revision 66, dated September I, 2015: 

• Chapter 72-31-08, Special Procedure 003, piece-part level ECI, 

• Chapter 72-00-31, Special Procedure 006, rotor assembly and module 

level ECI and, 

• Chapter 72-00-31, Special Procedure 007, rotor assembly level USI. 

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 accomplishing an ECI or USI of the stage 8 aft web upper face 

of the HPC stage 8-10 spool and removing from service those parts that fail inspection. 

Interim Action 

We consider this AD interim action. GE is determining the root cause for the 

unsafe condition identified in this AD. Once a root cause is identified, we might consider 

additional rulemaking. 

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 based on the reported engine failure. Therefore, we find that 

3 
not preceded by notice and an opportunity for public comment. 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 "Docket No. FAA-2015-6823; 

Directorate Identifier 2015-NE-38-AD" at the beginning of your comments. We 

specifically invite comments on the overall regulatory, economic, environmental, and 

energy aspects of this AD. We vvill 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 vvill 

also post a report summarizing each substantive verbal contact we receive about this AD. 

Costs of Compliance 

We estimate that this AD affects 1 engine installed on an airplane ofU.S. registry. 

We also estimate that it will take about 7 hours per engine to comply with this AD. The 

average labor rate is $85 per hour. Required parts cost about $780,000 per engine. Based 

on these figures, we estimate the total cost of the AD to U.S. operators to be $780,595. 

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 

4 
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 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. 

5 
No. FAA-2015-6823; Directorate Identifier 2015-NE-38-AD. 

(a) Effective Date 

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

PUBLICATION IN THE FEDERAL REGISTER]. 

(b) Affected ADs 

None. 

(c) Applicability 

This AD applies to General Electric Company (GE) GE90-76B, -77B, -85B, 

-90B, and -94B turbofan engines with high-pressure compressor (HPC) stage 8-10 spool, 

part number 1694M80G04, installed. 

(d) Unsafe Condition 

This AD was prompted by an uncontained failure of the HPC stage 8-10 spool, 

leading to an airplane fire. We are issuing this AD to prevent failure of the 1-IPC stage 

8-10 spool, uncontained rotor release, damage to the engine, and damage to the airplane. 

(e) Compliance 

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

(1) Perform an eddy current inspection or ultrasonic inspection of the stage 8 aft 

web upper face of the HPC stage 8-10 spool for cracks as follows: 

(i) For HPC stage 8-10 spools with serial number (SIN) GWNHC086 or 

GWNI-IB875, inspect within 150 cycles-in-service (CIS), after the effective date of this 

AD. 

6 
required by paragraph (e)(!) of this AD and replace the spool with a spool eligible for 

installation. 

(I) Alternative Methods of Compliance (AMOCs) 

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

AD. Use the procedures found in 14 CFR 39.19 to make your request. You may email 

your request to: ANE-AD-AMOC@faa.gov. 

(g) Related Information 

For more information about this AD, contact John Frost, Aerospace Engineer, 

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

Executive Park, Burlington, MA 01803; phone: 781-238-7756; fax: 781-238-7199; email: 

john.frost@faa.gov. 

(h) Material Incorporated by Reference 

None. 

Issued in Burlington, Massachusetts, on December 21, 2015. 

Colleen M; D'Alessandro, 

Directorate Manager, Engine & Propeller Directorate, 

Aircraft Certification Service. 

7