[4910-13-P] DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA-2012-0079; Directorate Identifier 2012-NE-06-AD; Amendment 39-17148; AD 2012-16-01] RIN 2120-AA64 Airworthiness Directives; Pratt & Whitney Divi sion Turbofan Engines AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for Pratt & Whitney Division PW4052, PW4152, PW4056, PW 4156A, PW4060, PW4060A, PW4060C, PW4062, PW4062A, PW4158, PW4460, PW4462, PW4164, PW4164C, PW4164C/B, PW4168, and PW4168A turbofan engines with ce rtain high-pressure turbine (HPT) stage 1 front hubs installed. This AD was prompt ed by Pratt & Whitney’s updated low-cyclefatigue analysis that indicated certain HPT stage 1 front hubs could initiate a crack prior to the published life limit. This AD require s removing the affected HPT stage 1 front hubs from service using a drawdown plan. We are issuing this AD to prevent failure of the HPT stage 1 front hub, which could lead to an uncontained engine failure and damage to the airplane. DATES: This AD is effective [INSER T DATE 35 DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER]. The Director of the Federal Register a pproved the incorporation by reference of certain publications listed in the AD as of [INSERT DATE 35 DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER]. ADDRESSES: For service information identified in this AD, contact Pratt & Whitney, 400 Main St., East Hartford, CT 06108; phone: 860-565-7700; fax: 860-565-1605. You2 may view this service information at the F AA, Engine & Propelle r 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 address for the Docket Office (phone: 800-647-5527) is Document Mana gement 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. FOR FURTHER INFORMATION CONTACT: James Gray, Aerospace Engineer, Engine Certification Office, FAA, 12 New England Executive Park, Burlington, MA; phone: 781-238-7742; fax: 781-238-7199; e-mail: james.e.gray@faa.gov. SUPPLEMENTARY INFORMATION: Discussion We issued a notice of proposed rulema king (NPRM) to amend 14 CFR part 39 to include an AD that would apply to the speci fied products. That NPRM published in the Federal Register on March 23, 2012 (77 FR 16967). That NPRM proposed to require removing the affected HPT stage 1 front hubs from service using a drawdown plan. Comments We gave the public the opportunity to participate in developing this AD. The following presents the comments received on the proposal and the FAA’s response to each comment.3 Support for the NPRM One commenter, The Boeing Company, suppor ted the contents of the proposed AD (77 FR 16967, March 23, 2012), as written. Request to Modify Applicability Commenters United Airlines, United Par cel Service Co. (UPS), Pratt & Whitney (P&W), and MNG Airlines requested that part numbers (P/Ns) 52L301 and 51L201-021 be added to the applicability paragraphs (c)(1) and (c)(2) of the proposed AD (77 FR 16967, March 23, 2012). The commenters noted that the applicability of the proposed AD is inconsistent since it includes some assembly P/Ns and some detail P/Ns. We agree. We revised the applicability paragraphs of this AD to include the referenced P/Ns for consistency. Request to Change Compliance Time Commenters UPS, MNG Airlines, and OnurAir requested that the compliance time be changed to “at next pi ece-part exposure after the e ffective date of this AD or before accumulating the number of cycles lis ted in this AD, whichever occurs later.” MNG Airlines indicated that its engines would lose 1,382 flig ht cycles, which would cost more than $1,000,000 and force early shop visits . Onur Air noted that its engines would lose 1,300 cycles and it would cause stub life problems on other life limited parts. UPS also expressed its concern over the increased shop burde n from a hub life reduction. We do not agree. We determined that removal of the HPT stage 1 front hubs according to the compliance times in paragr aph (f) of this AD provides an acceptable level of safety for the fleet. This acceptable level of safety would not be maintained if all HPT stage 1 front hubs were allowed to re main in service until the next piece-part exposure above the number of cycles listed in this AD. For this reason, we also cannot adjust the compliance time to account for potenti al stub life problems that might occur in the other rotors. We did not change the AD.4 Request to Reference the PW4000 Engine Manual Chapter 05 Life Limits Commenters MNG Airlines and P&W re quested that the phrase “former life limits cannot be exceeded” be added to complia nce paragraphs (f)(1)(ii) and (f)(2)(ii) of the proposed AD (77 FR 16967, March 23, 2012), orthat some other reference to the PW4000 Engine Manual Chapter 05 life limits be added when the stage 1 front hub is operating during the 1,000 cycl e drawdown. United commented that a reference to the reduced life limits be included in Chapter 05 of the Airworthiness Limitations Section (ALS) of the PW4000 Engine Manual. We do not agree. The Chapter 05 life lim its cannot be exceeded. For those hubs beneath the Chapter 05 life limit, this AD requires removal according to the drawdown schedule in the AD, which is before the Chapter 05 limit is reached. This AD’s requirements are independent from the Chapte r 05 life limits in the ALS of the PW4000 Engine Manual. We di d not change the AD. Request Revisions to Service Information to be Incorporated by Reference P&W, UPS, and United requested revisions to the service information that is incorporated by reference in the AD. P&W requested that the AD reference the new P&W Alert Service Bulletin (ASB) No. PW4ENG A72-821, dated July 6, 2012 and P&W ASB No. PW4G-100-A72-246, dated Ju ne 28, 2012, which address the unsafe condition and contain the aff ected part numbers by serial number for the PW4000-94” and PW4000-100” engines. UPS also asked th at the AD be revised to note that any subsequent revision of the service bulle tin (SB) can be used for compliance. We agree in part. Our proposed AD ( 77 FR 16967, March 23, 2012), referenced the P/N-serial number (S/N) tabl es of affected parts in the old SBs. We agree that we should use the new P&W SBs. We changed para graph (c) of this AD to incorporate the P/N-S/N tables from the new P&W ASBs, specifically from P&W ASB No. PW4ENG5 A72-821, dated July 6, 2012 and P&W AS B No. PW4G-100-A72-246, dated June 28, 2012. We disagree that the AD shoul d be revised to incorporate future revisions of an ASB because we do not know the contents of SBs not yet published. We did not change the AD based on UPS’s comment. Request to Modify Compliance Wording P&W requested that the phrase “or at th e next piece-part exposure after the effective date of this AD, whichever occu rs first” be removed from the compliance paragraphs (f)(1)(ii) and (f )(2)(ii). P&W indicated that, based on the proposed AD, operators may not be able to run HPT stage 1 front hubs, identified in paragraphs (c)(1)(i) and (c)(1)(ii), that are ex posed at piece-part between 17,000 and 18,000 cycles-since-new (CSN) and HPT stage 1 front hubs, identified in paragraphs (c)(2) a nd (c)(3), that are exposed between 12,700 and 13,700 CSN, to the full 1,000 cycle drawdown. We partially agree. We agree that th e AD if adopted as proposed could have forced removal of HPT stage 1 front hubs prior to reaching 18,000 CSN and 13,700 CSN, respectively. We disagree that we should remove the at pi ece-part exposure wording from paragraphs (f)(1)(ii) and (f)(2 )(ii) of the AD, because HPT stage 1 front hubs that are exposed at piece-part after 18,000 CSN and 13,700 CSN should not go back into service, even if they have not accumulated an additi onal 1,000 cycles in service. We therefore, revised paragraphs (f)(1)(ii ) and (f)(2)(ii) of the proposed AD (77 FR 16967, March 23, 2012), to clarify that these HPT stage 1 fronthubs should be removed at the next piecepart exposure above 18,000 CSN and 13,700 CSN, respectively, rather than at the next piece-part exposure after the eff ective date of the AD. This change is consistent with the installation prohibition for HPT stage 1 fr ont hubs in paragraph (g) of this AD. Request for Allowance for Mixed-Model Management United asked that the AD include an a llowance for mixed-model management.6 We do not agree. The AD does not restrict use of mixed-model management. If an operator uses mixed-model management, then 18,000 CSN and 13,700 CSN should be used in the calculation for the respective engi ne models included in paragraph (c) of this AD. We did not change the AD. Request to Add Credit for Prior Compliance FedEx Express (FedEx) asked that the AD include credit for compliance to prior SBs. We do not agree. Operators can take credit for previous actions based on paragraph (e) of this AD. We did not change the AD. Request to Clarify Requ irements for P/N 51L901 FedEx asked that the AD requirement s for stage 1 front hub, P/N 51L901, be clarified. FedEx claimed that the relevant service informa tion section of the AD and its applicability are contradictory. We do not agree. We reviewed the P/N references and find no contradictions between the two sections. We did not change the AD. Revision to Cost of Compliance In reviewing our cost of compliance estimate made in the NPRM (77 FR 16967, March 23, 2012), we found that our estimate was wrong. Specifically, we found that we based our estimate on the number of engines in stalled on airplanes worldwide rather than just on the U.S. fleet. Therefore, we changed our estimate to reflect U.S. operators only. This change reduced the number of engines affected from 954 to 289 and the total cost estimate from $23,049,537 to $6,981,578. Conclusion We reviewed the relevant data, c onsidered the comments received, and determined that air safety and the public interest require adopting the AD with the7 changes described previously. We also determ ined that these changes will not increase the economic burden on any operator nor increase the scope of the AD. Costs of Compliance We estimate that this AD would affect 289 engines installed on airplanes of U.S. registry. About 183 engines use a 20,000 CS N life limit for the HPT stage 1 front hub. For these engines, we estimate the lost part life to have a value of about $25,400 per engine. About 106 engines use a 15,000 CSN lif e limit. For these engines, we estimate the lost life to have a value of about $22,013 per engine. Based on these figures, we estimate the total cost of the AD to U.S. operators is $6,981,578. Authority for this Rulemaking Title 49 of the United States Code specifi es the FAA’s authority to issue rules on aviation safety. Subtitle I, section 106, descri bes 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 promo ting safe flight of civil aircraft in air commerce by prescribing regulations for pr actices, methods, and procedur es the Administrator finds necessary for safety in air commerce. This regu lation 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.8 For the reasons discussed above , I certify that this AD: (1) Is not a “significant regulator y 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, and (4) Will not have a significant economic impact, positive or negative, on a substantial number of small entities under th e criteria of the Regulatory Flexibility Act. List of Subjects in 14 CFR Part 39 Air transportation, Aircraft, Aviation safet y, Incorporation by reference, Safety. Adoption of the Amendment Accordingly, under the authority delegate d 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): 2012-16-01 Pratt & Whitney Division : Amendment 39-17148; Docket No. FAA-2012-0079; Directorat e Identifier 2012-NE-06-AD. (a) Effective Date This AD is effective [INSER T DATE 35 DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER]. (b) Affected ADs
None.9 (c) Applicability This AD applies to the following Pratt & Whitney Division turbofan engines: (1) PW4052, PW4152, and PW4056 turbofan en gines, including models with any dash number suffix, with a high-pressure tu rbine (HPT) stage 1 front hub part number (P/N) listed in Table 1 to paragraph (c) of this AD installed. (2) PW4156A, PW4060, PW4060A , PW4060C, PW4062, PW4062A, PW4158, PW4460, and PW4462 turbofan engines, including models with any dash number suffix, with an HPT stage 1 front hub P/N listed in Ta ble 1 to paragraph (c) of this AD installed. Table 1 to paragraph (c) P/N 51L601 All serial numbers (S/Ns).
P/N 52L401 With a S/N not listed in Table 5 of the Accomplishment Instructions of Pratt & Whitney Alert Service Bulletin (ASB) No. PW4ENG A72-821, dated July 6, 2012. P/N 51L201, P/N 51L201-001, P/N 51L201-021 All S/Ns.

P/N 51L901, P/N 52L301 With an S/N not listed in Table 7 of the Accomplishment Instructions of Pratt & Whitney ASB No. PW4ENG A72-821, dated July 6, 2012.

(3) PW4164, PW4164C, PW4164C/B, PW4168, and PW4168A turbofan engines with an HPT stage 1 front hub, P/N 51L901, insta lled with an S/N not listed in Table 3 of the Accomplishment Instructions of Pr att & Whitney ASB No. PW4G-100-A72-246, dated June 28, 2012.10 (d) Unsafe Condition This AD was prompted by Pratt & Whitney’s updated low-cycle-fatigue analysis that indicated certain HPT stage 1 front hubs could initiate a crack prior to the published life limit. This AD requires removing the affected HPT stage 1 front hubs from service using a drawdown plan. We are issuing this AD to prevent failure of the HPT stage 1 front hub, which could lead to an uncontained engine failure and dama ge to the airplane. (e) Compliance Comply with this AD within the complia nce times specified, unless already done. (f) Removal of HPT Stage 1 Front Hubs From Service (1) For HPT stage 1 front hubs listed in paragraph (c)(1) of this AD, do the following: (i) If the HPT stage 1 front hub has accumulated 17,000 or fewer cycles-sincenew (CSN) on the effective date of this AD, remove the HPT stage 1 front hub from service before accumulating 18,000 CSN. (ii) If the HPT stage 1 front hub has accumulated more than 17,000 CSN on the effective date of this AD, remove the HPT stage 1 front hub from service before accumulating an additional 1,000 cycles-in-se rvice (CIS) or at the next piece-part exposure above 18,000 CSN, wh ichever occurs first. (2) For HPT stage 1 front hubs listed in pa ragraphs (c)(2) and (c)(3) of this AD, do the following: (i) If the HPT stage 1 front hub has accumulated 12,700 or fewer CSN on the effective date of this AD, remove the HPT stage 1 front hub from service before accumulating 13,700 CSN. (ii) If the HPT stage 1 front hub has accumulated more than 12,700 CSN on the effective date of this AD, remove the HPT stage 1 front hub from service before11 accumulating an additional 1,000 CIS or at the next piece-part exposure above 13,700 CSN, whichever occurs first. (g) Installation Prohibition After the effective date of this AD, do not install into any engine any HPT stage 1 front hubs listed in paragraph (c)(1) of this AD that are at piece-part exposure and exceed 18,000 CSN, or any HPT stage 1 front hubs listed in paragraphs (c)(2) and (c)(3) of this AD that are at piece-part exposure and exceed 13,700 CSN. (h) Definition For the purpose of this AD, piece-part expos ure means that the part is completely disassembled and removed from the engine. (i) Alternative Methods of Compliance (AMOCs) The Manager, Engine Certification Offi ce, may approve AMOCs for this AD. Use the procedures found in 14 CFR 39.19 to make your request. (j) Related Information For more information about this AD, contact James Gray, Aerospace Engineer, Engine Certification Office, FAA, 12 New England Executive Park, Burlington, MA; phone: 781-238-7742; fax: 781-238-7199; e-mail: james.e.gray@faa.gov. (k) Material Incorporated by Reference (1) The Director of the Federal Register approved the incorporation by reference (IBR) of the following service information under 5 U.S.C. 552(a) and 1 CFR part 51. (2) You must use the following service in formation to do the actions required by this AD, unless the AD specifies otherwise: (i) Pratt & Whitney Aler t Service Bulletin (ASB) No. PW4ENG A72-821, dated July 6, 2012. (ii) Pratt & Whitney ASB No. PW4G-100-A72-246, dated June 28, 2012.12 (3) For service information identified in this AD, contact Pratt & Whitney, 400 Main St., East Hartford, CT 06108; phone: 860-565-7700; fax: 860-565-1605. (4) You may review this service inform ation at the FAA, Engine & Propeller Directorate, 12 New England Executive Par k, Burlington, MA. For information on the availability of this material at the FAA, call 781-238-7125. (5) You may also review the service inform ation that is incorporated by reference at the National Archives and Records Admi nistration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov /federal-register/cfr/ibr-locations.html. Issued in Burlington, Ma ssachusetts, on July 26, 2012.

Peter A. White, Manager, Engine & Propeller Directorate, Aircraft Certification Service.