# AD 95-08-15: Airworthiness Directives; Pratt & Whitney JT8D Series Turbofan Engines - Type: Airworthiness directive - Effective: May 9, 1995 - Published: April 24, 1995, 60 FR 20019–20021 - Issued as: Final rule; request for comments - Superseded by: Nothing supersedes this AD - Amendment: 39-9204 - Docket: 95-ANE-04 - Official PDF: https://openairdocs.org/files/sha256/04/a0/04a094723b0ba79db5034a4b93cbe98e5d451d2023e75a1bd47b308a145fdd10 (from https://www.govinfo.gov/content/pkg/FR-1995-04-24/pdf/95-9471.pdf) - Federal Register: https://www.federalregister.gov/documents/1995/04/24/95-9471/airworthiness-directives-pratt-and-whitney-jt8d-series-turbofan-engines - Page: https://openairdocs.org/ad/95-08-15 ## Summary This amendment adopts a new airworthiness directive (AD) that is applicable to Pratt & Whitney (PW) JT8D series turbofan engines. This action requires a one-time borescope inspection of certain combustion chamber outer cases (CCOC) installed only on McDonnell Douglas DC-9 series and Boeing 737 series aircraft, and an ultrasonic inspection of all affected CCOC's at every accessibility. This amendment is prompted by reports of two CCOC ruptures in service and of two CCOC's discovered during maintenance with intergranular cracks. The actions specified in this AD are intended to prevent CCOC rupture, which can result in an uncontained engine failure and damage to the aircraft. ## The airworthiness directive ### PART 39--AIRWORTHINESS DIRECTIVES 1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 106(g); and 14 CFR 11.89. ### Sec. 39.13 [Amended] 2. Section 39.13 is amended by adding the following new airworthiness directive: 95-08-15 Pratt & Whitney: Amendment 39-9204. Docket 95-ANE-04. Applicability: Pratt & Whitney (PW) Models JT8D-1, -1A, -1B, -7, -7A, -7B, -9, -9A, -11, -15, -15A, -17, -17A, -17R, and -17AR turbofan engines, with combustion chamber outer cases (CCOC) Part Numbers (P/N) 490547, 542155, 616315, 728829, 728829-001, 730413, 730413-001, 730414, 730414-001, 767197, 767279, and 767279-001. These engines are installed on but not limited to Boeing 737 series and 727 series, and McDonnell Douglas DC-9 series aircraft. Note: This AD applies to each engine identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For engines that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must use the authority provided in paragraph (f) to request approval from the FAA. This approval may address either no action, if the current configuration eliminates the unsafe condition, or different action necessary to address the unsafe condition described in this AD. Such a request should include an assessment of the effect of the changed configuration on the unsafe condition addressed by this AD. In no case does the presence of any modification, alteration, or repair remove any engine from the applicability of this AD. Compliance: Required as indicated, unless accomplished previously. To prevent CCOC rupture, which can result in an uncontained engine failure and damage to the aircraft, accomplish the following: ### (a) (a) For engines installed on McDonnell Douglas DC-9 series aircraft, perform the following: (1) Perform a borescope inspection of the CCOC for cracking within 1,000 cycles in service (CIS) after the effective date of this airworthiness directive (AD), in accordance with Section 2.A of PW Alert Service Bulletin (ASB) No. A6202, dated February 20, 1995. (2) Remove from service CCOC's that exhibit cracking in accordance with Section 2.A of PW ASB No. A6202, dated February 20, 1995. ### (b) (b) For engines installed on Boeing 737 series aircraft, perform the following: (1) Perform a borescope inspection of the CCOC for cracking within 1,500 CIS after the effective date of this AD, in accordance with Section 2.A of PW ASB No. A6202, dated February 20, 1995. (2) Remove from service CCOC's that exhibit cracking in accordance with section 2.A of PW ASB No. A6202, dated February 20, 1995. ### (c) (c) At every accessibility of the CCOC after the effective date of this AD, perform the following: (1) Prior to reassembly of the outer split fan ducts, perform an ultrasonic inspection for cracking in accordance with Section 2.B of [[Page 20021]] PW ASB No. A6202, dated February 20, 1995. (2) Remove from service CCOC's that exhibit cracking in accordance with Section 2.B of PW ASB No. A6202, dated February 20, 1995. ### (d) (d) Compliance with paragraph (c) of this AD is an acceptable alternative to performing the borescope inspection required by paragraph (a) or (b) of this AD, as applicable. ### (e) (e) For the purpose of this AD, accessibility of the CCOC is defined as separation of the ``J'' and ``K'' flanges and removal of the outer split fan ducts. ### (f) (f) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Engine Certification Office. The request should be forwarded through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Engine Certification Office. Note: Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the Engine Certification Office. ### (g) (g) Special flight permits may be issued in accordance with Secs. 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the aircraft to a location where the requirements of this AD can be accomplished. ### (h) (h) The inspections of the CCOC shall be done in accordance with the following service document: ------------------------------------------------------------------------ Document No. Pages Date ------------------------------------------------------------------------ PW ASB No. A6202......................... 1-11 Feb. 20, 1995. Total pages: 11. ------------------------------------------------------------------------ This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Pratt & Whitney, 400 Main St, East Hartford, CT 06108. Copies may be inspected at the FAA, New England Region, Office of the Assistant Chief Counsel, 12 New England Executive Park, Burlington, MA; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. ### (i) (i) This amendment becomes effective on May 9, 1995. Issued in Burlington, Massachusetts, on April 11, 1995. James C. Jones, Acting Manager, Engine and Propeller Directorate, Aircraft Certification Service. ## Rule preamble ### Dates Effective May 9, 1995. The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of May 9, 1995. Comments for inclusion in the Rules Docket must be received on or before June 23, 1995. ### Addresses Submit comments in triplicate to the Federal Aviation Administration (FAA), New England Region, Office of the Assistant Chief Counsel, Attention: Rules Docket No. 95-ANE-04, 12 New England Executive Park, Burlington, MA 01803-5299. The service information referenced in this AD may be obtained from Pratt & Whitney, 400 Main St, East Hartford, CT 06108. This information may be examined at the FAA, New England Region, Office of the Assistant Chief Counsel, 12 New England Executive Park, Burlington, MA; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. ### For further information contact Mark A. Rumizen, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; telephone (617) 238-7137, fax (617) 238-7199. ### Supplementary information The Federal Aviation Administration (FAA) has received reports of two uncontained engine failures on Pratt & Whitney (PW) JT8D series turbofan engines. Investigation revealed that the engine failures were due to combustion chamber outer case (CCOC) ruptures that exhibited intergranular cracking. The CCOC ruptures resulted from the low cycle fatigue (LCF) propagation of the intergranular crack. In addition, intergranular cracking on two other CCOC's was discovered during in-shop maintenance. The FAA has determined that intergranular cracks may develop from an initiation site on the case during assembly of the CCOC to the high pressure turbine (HPT) case, or during engine operation in which an impact load is imposed on the CCOC. During subsequent engine operation, the crack can then propagate to failure due to normal LCF loads. Analysis of operating experience relative to CCOC ruptures indicated that only engines installed on McDonnell Douglas DC-9 series and Boeing 737 series aircraft have a significant risk of CCOC rupture, whereas engines installed on other aircraft have been statistically proven to have less risk of CCOC rupture. Therefore, the FAA has determined that a borescope inspection of CCOC's installed only on McDonnell Douglas DC-9 series and Boeing 737 series aircraft is required to meet safety of flight criteria. However, the FAA has determined that an ultrasonic inspection of all affected CCOC's during in-shop maintenance is also required, regardless of intended aircraft installation, to meet safety of flight criteria. This condition, if not corrected, could result in CCOC rupture, which can result in an uncontained engine failure and damage to the aircraft. The FAA has reviewed and approved the technical contents of PW Alert Service Bulletin (ASB) No. A6202, dated February 20, 1995, that describes procedures for a one-time borescope inspection of certain CCOC's installed [[Page 20020]] only on McDonnell Douglas DC-9 series and Boeing 737 series aircraft, and an ultrasonic inspection of all affected CCOC's at every accessibility when the ``J'' and ``K'' flanges are separated and the outer split fan ducts are removed. Since an unsafe condition has been identified that is likely to exist or develop on other PW JT8D series turbofan engines of the same type design, this AD is being issued to prevent CCOC rupture, which can result in an uncontained engine failure and damage to the aircraft. This AD requires a one-time borescope inspection of certain CCOC's installed only on McDonnell Douglas DC-9 series and Boeing 737 series aircraft, and an ultrasonic inspection of all affected CCOC's at every accessibility when the ``J'' and ``K'' flanges are separated and the outer split fan ducts are removed. However, performing the ultrasonic inspection in the shop or on-wing is an acceptable alternative to performing the borescope inspection. The actions are required to be accomplished in accordance with the ASB described previously. Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days. ### Comments Invited Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications should identify the Rules Docket number and be submitted in triplicate to the address specified under the caption ADDRESSES. All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed. Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket. Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made: ``Comments to Docket Number 95-ANE-04.'' The postcard will be date stamped and returned to the commenter. The regulations adopted herein will not have substantial direct effects 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. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment. The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and is not a ``significant regulatory action'' under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, may be obtained from the Rules Docket at the location provided under the caption ADDRESSES. ### List of Subjects in 14 CFR Part 39 Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. ### Adoption of the Amendment Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows: No proposed rule in this release led to it. Its text cites no advisory circulars or STCs. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.