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Federal Register / Vol. 86, No. 181 / Wednesday, September 22, 2021 / Rules and Regulations 0140; fax: 860 5655442; email:
help24@prattwhitney.com; website:
https fleetcare.prattwhitney.com. You may view this service information at the FAA, Airworthiness Products Section, Operational Safety Branch, 1200 District Avenue, Burlington, MA 01803. For information on the availability of this material at the FAA, call 781 238
7759. It is also available at https
www.regulations.gov by searching for and locating Docket No. FAA2021
0515.
Examining the AD Docket You may examine the AD docket at https www.regulations.gov by searching for and locating Docket No.
FAA20210515; or in person at Docket Operations between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this final rule, any comments received, and other information. The address for Docket Operations is U.S. Department of Transportation, Docket Operations, M
30, West Building Ground Floor, Room W12140, 1200 New Jersey Avenue SE, Washington, DC 20590.
FOR FURTHER INFORMATION CONTACT:
Mark Taylor, Aviation Safety Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone:
781 2387229; fax: 781 2387199;
email: Mark.Taylor@faa.gov.
SUPPLEMENTARY INFORMATION:
Background The FAA issued a notice of proposed rulemaking NPRM to amend 14 CFR
part 39 by adding an AD that would apply to all Pratt & Whitney PW1500G
and PW1900G series turbofan engines with a certain HPT 1st-stage hub or HPT
rotor 1st-stage blade retaining plate installed. The NPRM published in the
Federal Register on June 29, 2021 86
FR 34166. The NPRM was prompted by a report from the manufacturer who determined that the HPT 1st-stage hub and HPT rotor 1st-stage blade retaining plate fail to meet the published lifecycle limits for each part. In the NPRM, the FAA proposed to require removal and replacement of the HPT 1st-stage hub and HPT rotor 1st-stage blade retaining plate prior to reaching certain cycle limits. The FAA is issuing this AD
to address the unsafe condition on these products.
Discussion of Final Airworthiness Directive Comments The FAA received comments from two commenters. The commenters were Delta Air Lines, Inc. DAL and the Air Line Pilots Association, International ALPA. The following presents the comments received on the NPRM and the FAAs response to each comment.
Request To Correct Required Actions DAL requested that the FAA change paragraph g1ii of this AD from removing the affected part and replacing with a part eligible for installation at the next engine shop visit after accumulating 4,700 CSN. . . to at the next engine shop visit after accumulating 4,960 CSN. . . to mirror the 4,960 CSN listed earlier in the paragraph. DAL suggested that 4,700
CSN is a typographical error.
The FAA disagrees that 4,700 CSN
is a typographical error. It is the cyclic value at which point certain HPT parts are to be removed from service. In contrast, 4,960 CSN on the effective date of this AD is a calculated point at which HPT-part removal requirements transition from the requirements of
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paragraph g1ii of this AD to the requirements of paragraph g1iii of this AD. 4,960 CSN and 4,700 CSN
are different in their function and how they are calculated. The FAA did not change this AD.
Support for the AD
ALPA expressed support for the NPRM as written.
Conclusion The FAA reviewed the relevant data, considered any comments received, and determined that air safety requires adopting this AD as proposed.
Accordingly, the FAA is issuing this AD
to address the unsafe condition on these products. This AD is adopted as proposed in the NPRM.
Related Service Information The FAA reviewed Pratt & Whitney Service Bulletin SB PW1000GA72
00011500B930AD, Issue No. 001, dated April 26, 2021, and Pratt &
Whitney SB PW1000GA72000168
00A930AD, Issue No. 001, dated April 26, 2021. These SBs describe procedures for removing and replacing the HPT 1st-stage hub and HPT rotor 1st-stage blade retaining plate.
Costs of Compliance The FAA estimates that this AD
affects 88 engines installed on airplanes of U.S. registry. The FAA estimates that in most cases the affected HPT 1st-stage hub and the affected HPT 1st-stage blade retaining plate will both be replaced during the same disassembly of the engine. This cost estimate therefore reflects the cost of replacing both parts during the same engine disassembly.
The FAA estimates the following costs to comply with this AD:

ESTIMATED COSTS
Action
Labor cost
Replace HPT 1st-stage hub and HPT rotor 1st-stage blade retaining plate pro-rated part cost.

300 work-hours $85 per hour = $25,500

Authority for This Rulemaking Title 49 of the United States Code specifies the FAAs 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 Agencys authority.
The FAA is issuing this rulemaking under the authority described in
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Parts cost
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
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$86,252

Cost per product $111,752

Cost on U.S.
operators $9,834,176

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
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