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Airworthiness Directives; General Electric Company Turbofan Engines

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AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Final rule.

Start Printed Page 17934

SUMMARY:

We are superseding Airworthiness Directive (AD) 2016-13-05 for all General Electric Company (GE) GE90-76B, GE90-77B, GE90-85B, GE90-90B, and GE90-94B turbofan engines. AD 2016-13-05 required eddy current inspection (ECI) of the high-pressure compressor (HPC) stage 8-10 spool at each shop visit for all affected engines and ECI or ultrasonic inspection (USI) for certain affected engines. This new AD requires initial and repetitive on-wing USIs of the HPC stage 8-10 spool for certain engines prior to shop visit and ECI of all affected engines at each shop visit. This AD was prompted by analysis that the risk of the failure of an HPC stage 8-10 spool was excessive without repetitive USI prior to shop visit. We are issuing this AD to correct the unsafe condition on these products.

DATES:

This AD is effective May 19, 2017.

ADDRESSES:

For service information identified in this final rule, contact General Electric Company, GE-Aviation, Room 285, 1 Neumann Way, Cincinnati, OH 45215, phone: 513-552-3272; fax: 513-552-3329; email: geae.aoc@ge.com. You may view this service information at the FAA, Engine & Propeller Directorate, 1200 District Avenue, 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 by searching for and locating Docket No. FAA-2015-7491; 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 W12-140, 1200 New Jersey Avenue SE., Washington, DC 20590.

Start Further Info

FOR FURTHER INFORMATION CONTACT:

John Frost, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 1200 District Avenue, Burlington, MA 01803; phone: 781-238-7756; fax: 781-238-7199; email: john.frost@faa.gov.

End Further Info End Preamble Start Supplemental Information

SUPPLEMENTARY INFORMATION:

Discussion

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to supersede AD 2016-13-05, Amendment 39-18569 (81 FR 41208, June 24, 2016; corrected 81 FR 42475, June 30, 2016), (“AD 2016-13-05”). AD 2016-13-05 applied to all GE GE90-76B, GE90-77B, GE90-85B, GE90-90B, and GE90-94B turbofan engines. The NPRM published in the Federal Register on December 19, 2016 (81 FR 91880). The NPRM was prompted by an uncontained failure of the HPC stage 8-10 spool, leading to an airplane fire. The NPRM proposed to require an ECI or USI of the HPC stage 8-10 spool and removing from service those parts that fail inspection. 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.

Comments

We gave the public the opportunity to participate in developing this AD. The following presents the comments received on the NPRM and the FAA's response to each comment.

Request To Revise Compliance

The Boeing Company (Boeing) and GE requested paragraph (f)(1)(i) be changed to apply to ECIs performed between January 2016 and July 29, 2016. Boeing and GE stated that operators who performed an ECI between January 2016 and July 29, 2016 are in accordance with GE GE90 Service Bulletin (SB) 72-1151, Initial issue or Revision 1.

We agree. Credit should be given for ECIs performed in accordance with GE GE90 SB 72-1151, Initial issue or Revision 1. We added paragraph (f)(2)(iii) to the Compliance section.

Request To Revise Compliance Time

Boeing and GE requested paragraph (f)(1)(ii) be changed to state that if it has been more than 400 cycles since the qualified initial USI inspection, then, inspect within 100 cycles from the effective date of this AD. Boeing and GE stated that this provides the operators with a reasonable amount of time to perform the USI.

We disagree. The date for the initial inspection was based on the effective date of AD 2016-13-05. The USI requirement is unchanged, so the 500 cycle allowance mandated in AD 2016-13-05 is also mandated by this AD. We did not change this AD.

Request To Revise Service Information

Boeing, GE, and Japan Air Lines (JAL) requested updating the Related Information section to reflect the latest version of the GE SB. GE SB 72-1151 was revised to Revision 01 on September 13, 2016 and includes the most recent details and aligns with this AD.

We agree. GE GE90 SB 72-1151, Revision 01, dated September 13, 2016, includes the most recent details, aligns with this AD, and also meets the risk analysis performed. We added GE GE90 SB 72-1151, Revision 01, dated September 13, 2016 and GE GE90 SB 72-1151, Revision 0, dated June 10, 2016 to paragraph (i)(2) of this AD.

Request To Revise Service Information

JAL requested updating paragraph (i)(2) Related Information, to perform an ECI in accordance with future revisions of the service information. JAL also requested updating paragraph (i)(2) Related Information, to add “and later” to the revision number relating to Chapter 72-31-08; Special Procedure 003 and 72-00-31 Special Procedure 006 in GE GE90 Engine Manual, GEK100700, Revision 68, dated September 1, 2016.

We disagree. We are only authorized to mandate use of service information that we have reviewed and which are published. Since future revisions of service information are not yet published, we are not authorized to mandate their use. We did not change this AD.

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 have determined that these minor changes:

  • Are consistent with the intent that was proposed in the NPRM, for correcting the unsafe condition; and
  • Do not add any additional burden upon the public than was already proposed in the NPRM.

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

We reviewed GE GE90 SB 72-1151, Revision 01, dated September 13, 2016. The SB describes procedures for an on-wing USI of the stage 8 web of the stage 8-10 spool. 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.

We also reviewed Chapter 72-31-08, Special Procedures 003; and Chapter 72-00-31, Special Procedures 006, in the GE GE90 Engine Manual, GEK100700, Revision 68, dated Start Printed Page 17935September 1, 2016. These procedures describe how to perform ECI of the stage 8 aft web of the stage 8-10 spool.

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 determined, we will consider additional rulemaking.

Costs of Compliance

We estimate that this AD affects 54 engines installed on airplanes of U.S. registry.

We estimate the following costs to comply with this AD:

Estimated Costs

ActionLabor costParts costCost per productCost on U.S. operators
Inspection7 work-hours × $85 per hour = $595 per inspection cycle$0$595 per inspection cycle$32,130 per inspection cycle.

We estimate the following costs to do any necessary replacements that would be required based on the results of the inspection. We have no way of determining the number of engines that might need this replacement:

On-Condition Costs

ActionLabor costParts costCost per product
Replacement of spool0 work-hours × $85 per hour = $0$780,000$780,000

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

We have determined that 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.

Start List of Subjects

List of Subjects in 14 CFR Part 39

  • Air transportation
  • Aircraft
  • Aviation safety
  • Incorporation by reference
  • Safety
End List of Subjects

Adoption of the Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows:

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PART 39—AIRWORTHINESS DIRECTIVES

End Part Start Amendment Part

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

End Amendment Part Start Authority

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

End Authority
[Amended]
Start Amendment Part

2. The FAA amends § 39.13 by removing Airworthiness Directive (AD) 2016-13-05, Amendment 39-18569 ( 81 FR 41208, June 24, 2016; corrected 81 FR 42475, June 30, 2016), and adding the following new AD:

End Amendment Part

2017-08-05 General Electric Company: Amendment 39-18854; Docket No. FAA-2015-7491; Directorate Identifier 2015-NE-39-AD

(a) Effective Date

This AD is effective May 19, 2017.

(b) Affected ADs

This AD replaces AD 2016-13-05, Amendment 39-18569 (81 FR 41208, June 24, 2016; corrected June 30, 2016, 81 FR 42475).

(c) Applicability

This AD applies to General Electric Company (GE) GE90-76B, GE90-77B, GE90-85B, GE90-90B, and GE90-94B turbofan engines with a high-pressure compressor (HPC) stage 8-10 spool, part numbers (P/Ns) 1694M80G04, 1844M90G01, or 1844M90G02, installed.

(d) Subject

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

(e) Unsafe Condition

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

(f) Compliance

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

(1) For HPC stage 8-10 spool, P/N 1694M80G04, all serial numbers (S/Ns), or HPC stage 8-10 spool, P/N 1844M90G01 or 1844M90G02, with a S/N listed in Figure 1 to paragraph (f) of this AD; perform an on-wing ultrasonic inspection (USI) of the stage 8 aft web upper face as follows:

(i) Perform an initial USI after reaching 8,000 cycles since new (CSN), but, before exceeding 9,000 CSN, or within 500 cycles in service after July 29, 2016, whichever occurs later.

(ii) Thereafter, perform a USI of the stage 8 aft web upper face every 500 cycles since last inspection.Start Printed Page 17936

(iii) Compliance with paragraph (f)(2)(i) or (f)(2)(iii) of this AD is terminating action for the initial and repetitive USIs specified by paragraphs (f)(1)(i) and (ii) of this AD.

Figure 1 to Paragraph (f)—HPC Stage 8-10 Spool S/Ns

Part Nos.Serial Nos.
1844M90G01GWN005MFGWNBK753GWNBS077GWNBS497GWNBS724
GWN005MGGWNBK754GWNBS078GWNBS499GWNBS794
GWN0087MGWNBK841GWNBS079GWNBS500GWNBS810
GWN0087NGWNBK842GWNBS080GWNBS501GWNBS811
GWN00DGKGWNBK843GWNBS081GWNBS502GWNBS812
GWN00DGLGWNBK844GWNBS157GWNBS609GWNBS813
GWNBJ992GWNBK952GWNBS158GWNBS610GWNBS814
GWNBK667GWNBK953GWNBS159GWNBS611GWNBS910
GWNBK674GWNBK954GWNBS160GWNBS612GWNBS911
GWNBK675GWNBK955GWNBS266GWNBS613GWNBS912
GWNBK743GWNBK956GWNBS267GWNBS614GWNBS914
GWNBK744GWNBK957GWNBS268GWNBS721GWNBS915
GWNBK751GWNBK958GWNBS269GWNBS722GWNBS982
GWNBK752GWNBK959GWNBS270GWNBS723GWNBS983
1844M90G02GWN00C2TGWN01C5NGWN02N8DGWN03RTMGWN04E21
GWN00C2VGWN01GE2GWN02T3RGWN03RTPGWN04GHT
GWN00G2NGWN01GE3GWN02WGMGWN040RLGWN04GHW
GWN00G2PGWN01GE4GWN0311KGWN040RMGWN04GJ0
GWN00PFPGWN01GE6GWN035PPGWN040RNGWN04JW6
GWN00PFRGWN01WH1GWN038TDGWN040RPGWN04JW7
GWN00T2NGWN02688GWN039TGGWN04202GWN04JW8
GWN00YHVGWN02689GWN03G2RGWN0435WGWN04L7K
GWN0125GGWN0268AGWN03G2WGWN04360GWN04L7L
GWN0125HGWN02DP2GWN03G30GWN04361GWN04MT7
GWN0166KGWN02DP3GWN03JPCGWN04362GWN04MT8
GWN01C5KGWN02F9FGWN03JPDGWN04ATGGWNBS984
GWN01C5LGWN02F9GGWN03N8PGWN04ATH
GWN01C5MGWN02L9TGWN03N8RGWN04E20

(2) For all HPC stage 8-10 spools, P/N 1694M80G04, 1844M90G01, or 1844M90G02, perform an eddy current inspection (ECI) of the stage 8 aft upper face as follows:

(i) Perform an initial ECI of the stage 8 aft web upper face at the next shop visit after the effective date of this AD.

(ii) Thereafter, perform an ECI of the stage 8 aft web upper face at each subsequent shop visit.

(iii) If you performed an ECI of the stage 8 aft web upper surface before the effective date of the AD, you met the requirements of paragraph (f)(2)(i) of this AD.

(3) Remove from service any HPC stage 8-10 spool that fails the inspection required by paragraphs (f)(1) or (2) of this AD, and replace with a spool eligible for installation.

(g) Definition

For the purpose of this AD, an engine shop visit is the induction of an engine into the shop for maintenance during which the compressor discharge pressure seal face is exposed.

(h) 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.

(i) Related Information

(1) For more information about this AD, contact John Frost, Aerospace Engineer, Engine Certification Office, FAA, 1200 District Avenue, Burlington, MA 01803; phone: 781-238-7756; fax: 781-238-7199; email: john.frost@faa.gov.

(2) GE GE90 Service Bulletin (SB) 72-1151, Revision 01, dated September 13, 2016; GE GE90 SB 72-1151, Revision 0, dated June 10, 2016; Chapter 72-31-08, Special Procedures 003; and Chapter 72-00-31, Special Procedures 006, in GE GE90 Engine Manual, GEK100700, Revision 68, dated September 1, 2016, can be obtained from GE using the contact information in paragraph (i)(3) of this AD. These SBs describe procedures for an on-wing USI of the stage 8 web of the stage 8-10 spool. These engine manual procedures describe how to perform ECI of the stage 8 aft web of the stage 8-10 spool.

(3) For service information identified in this AD, contact General Electric Company, GE-Aviation, Room 285, 1 Neumann Way, Cincinnati, OH 45215, phone: 513-552-3272; fax: 513-552-3329; email: geae.aoc@ge.com.

(4) You may view this service information at the FAA, Engine & Propeller Directorate, 1200 District Avenue, Burlington, MA. For information on the availability of this material at the FAA, call 781-238-7125.

(j) Material Incorporated by Reference

None.

Start Signature

Issued in Burlington, Massachusetts, on April 5, 2017.

Carlos A. Pestana,

Acting Manager, Engine & Propeller Directorate, Aircraft Certification Service.

End Signature End Supplemental Information

[FR Doc. 2017-07476 Filed 4-13-17; 8:45 am]

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