AD 98-4408

[Federal Register Volume 63, Number 37 (Wednesday, February 25, 1998)] [Rules and Regulations] [Pages 9405-9408] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 98-4408]

-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-ANE-04-AD; Amendment 39-10351; AD 98-04-39] RIN 2120-AA64

Airworthiness Directives; Pratt & Whitney JT8D Series Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

-----------------------------------------------------------------------

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 the combustion chamber outer case (CCOC) for cracks on engines identified by serial number that were ultrasonically inspected in accordance with AD 96-23- 14 with defective probes. In addition, this AD requires an ultrasonic probe functional check at PW prior to using the probe to perform an ultrasonic inspection if the probe was overhauled, repaired, or otherwise altered since original manufacture and not subsequently functionally checked by PW. This amendment is prompted by reports of defective probes discovered in the field. The actions specified in this AD are intended to prevent uncontained engine failure, inflight engine shutdown, engine cowl release, and airframe damage.

DATES: Effective February 25, 1998. The incorporation by reference of Pratt & Whitney Alert Service Bulletin No. A6202, Revision 1, dated January 4, 1996, as listed in the regulations, was approved previously by the Director of the Federal Register as of January 2, 1997 (61 FR 63707, December 2, 1996). Comments for inclusion in the Rules Docket must be received on or before April 27, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 98-ANE-04-AD, 12 New England Executive Park, Burlington, MA 01803-5299. Comments may also be sent via the Internet using the following address: ``9-ad- [email protected]''. Comments sent via the Internet must contain the docket number in the subject line. The service information referenced in this AD may be obtained from Pratt & Whitney, 400 Main St., East Hartford, CT 06108; telephone (860) 565-6600, fax (860) 565-4503. This information may be examined at the FAA, New England Region, Office of the Regional 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: Christopher Spinney, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; telephone (781) 238-7175, fax (781) 238-7199.

SUPPLEMENTARY INFORMATION: On November 7, 1996, the Federal Aviation Administration (FAA) issued airworthiness directive (AD) 96-23-14, Amendment 39-9820 (61 FR 63707, December 2, 1996), which supersedes ADs 87-11-07 R1 and 95-08-15, to require repetitive eddy current, fluorescent penetrant, fluorescent magnetic particle, or visual inspections for cracks in the rear flange, and ultrasonic, fluorescent penetrant, or fluorescent magnetic particle inspections for cracks in the PS4 boss, and drain bosses of the combustion chamber outer case (CCOC); and an additional inspection of the CCOC rear flange for intergranular cracking. In addition, AD 96-23-14 reduces the rear flange inspection interval for CCOCs when only the aft face of the rear flange has been inspected, and introduces an improved ultrasonic probe assembly. Also, AD 96-23-14 introduces a rotating eddy current probe for shop inspections in which the case is removed from the engine. Finally, AD 96-23-14 eliminates fluorescent penetrant inspection (FPI), fluorescent magnetic particle inspection (FMPI), and visual inspections from hot section disassembly level inspection procedures. That action was prompted by reports of crack origins in the forward face of the rear flange that could not be detected by the inspection methods for installed CCOCs that were mandated in the superseded ADs 87-11-07 R1 and 95-08-15. That condition, if not corrected, could result in uncontained engine failure, inflight engine shutdown, engine cowl release, and airframe damage. Since the issuance of AD 96-23-14, the FAA has received reports of 13

[[Page 9406]]

defective ultrasonic inspection probes used to accomplish the ultrasonic inspections required by AD 96-23-14. Those 13 defective probes have been identified and removed from the field, but the engines inspected with the defective probes must be reinspected. Other ultrasonic inspection probes were either overhauled, repaired, or otherwise altered since original manufacture and were not subsequently functionally checked to insure that they met the necessary inspection sensitivity requirements. The calibration check contained in the ultrasonic inspection procedure does not serve as an adequate check to insure that the probe meets inspection sensitivity requirements. Currently, only PW has the capability to perform the necessary functional check to the proper standard. The FAA has reviewed and approved the technical contents of PW Alert Service Bulletin (ASB) No. A6202, Revision 1, dated January 4, 1996, that describes procedures for a borescope inspection of the CCOC rear flange for cracks. This ASB identifies applicability to engines installed on McDonnell Douglas DC-9 and Boeing 737 series engines only; however, the inspection requirements of paragraph 2.A.(5) of PW ASB No. A6202, Revision 1, dated January 4, 1996, are applicable to engines installed on Boeing 727 series aircraft as well. Since an unsafe condition has been identified that is likely to exist or develop on other engines of the same type design, this AD is being issued to prevent an uncontained engine failure. This AD requires a borescope inspection of engines, identified by serial number (S/N) that were ultrasonically inspected in accordance with AD 96-23-14 with defective probes. In addition, this AD requires a functional check at PW of all ultrasonic inspection probes that were overhauled, repaired, or otherwise altered since original manufacture and not subsequently functionally checked. The borescope inspection is 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 98-ANE-04-AD.'' 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:

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.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding the following new airworthiness directive:

98-04-39 Pratt & Whitney: Amendment 39-10351. Docket 98-ANE-04-AD.

Applicability: Pratt & Whitney (PW) JT8D-1, -1A, -1B, -7, -7A, - 7B, -9, -9A, -11, -15, -15A, -17, -17A, -17R, and -17AR turbofan engines, with combustion chamber outer case (CCOC) part numbers (P/ Ns) 490547, 542155, 616315, 728829, 728829-001, 730413, 730413-001, 730414, 730414-001, 767197, 767279, 767279-001 installed. These engines are installed on but not limited to Boeing 737 and 727 series, and McDonnell Douglas DC-9 series aircraft.

Note 1: This airworthiness directive (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 request approval for an alternative method of compliance in accordance with paragraph (c) of this AD. The request should include an assessment of the effect of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously. To prevent uncontained engine failure, inflight engine shutdown, engine cowl release, and airframe damage, accomplish the following: (a) For engines identified by serial number (S/N) in Table 1 of this AD, perform a one-time borescope inspection of the CCOC rear flange in accordance with paragraph 2.A.(5) of PW Alert Service Bulletin (ASB) No. A6202, Revision 1, dated January 4, 1996, as follows:

[[Page 9407]]

Table 1 ----------------------------------------------------------------------------------------------------------------

---------------------------------------------------------------------------------------------------------------- 648796......... 653799 655969 665370 674333 695297 702602 648859......... 653876 655987 665372 674370 696555 702648 649077......... 653904 656036 665382 674513 696573 702699 649135......... 654043 656084 665393 674564 696645 702712 649157......... 654115 656121 665520 674580 696668 702772 649212......... 654428 656948 665529 674611 696757 707158 649262......... 654557 656964 665744 687407 700037 707200 649331......... 654804 657064 665992 687457 700053 707405 649354......... 654860 657119 666004 687634 700103 707922 649406......... 654877 657386 666019 687851 700140 708332 649451......... 654915 657418 666076 687891 700145 708921 649675......... 654949 657584 666331 687893 700156 709002 653316......... 654986 657613 666682 688029 700223 709168 653329......... 655108 657677 666715 688051 700243 709209 653363......... 655310 657739 666948 688054 700248 653495......... 655437 665410 667042 688103 700261 653514......... 655821 665412 667045 688161 700334 653545......... 655842 665461 667059 688470 700383 653574......... 655857 665468 667068 688491 700398 653609......... 655870 665489 667110 688499 700404 653622......... 655898 665497 674193 689934 700665 653789......... 655900 665364 674251 695290 700133 ----------------------------------------------------------------------------------------------------------------

(1) For engines installed on McDonnell Douglas DC-9 series aircraft, inspect within 1,000 cycles in service (CIS) since the last ultrasonic inspection of the CCOC rear flange performed in accordance with AD 96-23-14, or within 100 CIS after the effective date of this AD, whichever occurs later. (2) For engines installed on Boeing 737 series aircraft, inspect within 1,500 CIS since the last ultrasonic inspection of the CCOC rear flange performed in accordance with AD 96-23-14, or within 100 CIS after the effective date of this AD, whichever occurs later. (3) For engines installed on Boeing 727 series aircraft, inspect within 2,500 CIS since the last ultrasonic inspection of the CCOC rear flange performed in accordance with AD 96-23-14, or within 100 CIS after the effective date of this AD, whichever occurs later. (b) If the ultrasonic probe assembly, PWA 47942, used to inspect the CCOC rear flange in accordance with AD 96-23-14 was overhauled, repaired, or otherwise altered since original manufacture and not subsequently functionally checked at PW, within 30 days after the effective date of this AD return ultrasonic probes to PW to perform a functional check of the ultrasonic probe assembly.

Note 2: Operators should note that future inspections performed using the probe must be performed with a probe that has passed a functional check at PW since overhaul, repair, or alteration.

(1) If the ultrasonic probe assembly does not pass the functional check, PW must inform the operator, within 24 hours after the probe fails the functional check. (2) If the ultrasonic probe assembly does not pass the functional check at PW, all engines that were ultrasonically inspected with that probe in accordance with AD 96-23-14 must be borescope inspected in accordance with paragraph 2.A.(5) of PW ASB No. A6202, Revision 1, dated January 4, 1996. Perform the inspections as follows: (i) For engines installed on McDonnell Douglas DC-9 series aircraft, inspect within 1,000 cycles in service (CIS) since the last ultrasonic inspection of the CCOC rear flange performed in accordance with AD 96-23-14, or within 100 CIS after determining the probe is defective, whichever occurs later. (ii) For engines installed on Boeing 737 series aircraft, inspect within 1,500 CIS since the last ultrasonic inspection of the CCOC rear flange performed in accordance with AD 96-23-14, or within 100 CIS after determining the probe is defective, whichever occurs later. (iii) For engines installed on Boeing 727 series aircraft, inspect within 2,500 CIS since the last ultrasonic inspection of the CCOC rear flange performed in accordance with AD 96-23-14, or within 100 CIS after determining the probe is defective, whichever occurs later. (c) 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. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Engine Certification Office.

Note 3: Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the Engine Certification Office.

(d) Special flight permits may be issued in accordance with sections 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. (e) The actions required by this AD shall be done in accordance with the following PW ASB:

---------------------------------------------------------------------------------------------------------------- Document No. Pages Revision Date ---------------------------------------------------------------------------------------------------------------- A6202.............................. 1-10 1............................... Jan. 4, 1996. 11 Original........................ Feb. 20, 1995. NDIP-835........................... 1-17 A............................... Oct. 7, 1995. Total pages: 28. ----------------------------------------------------------------------------------------------------------------

This incorporation by reference of Pratt & Whitney Alert Service Bulletin No. A6202, Revision 1, dated January 4, 1996, was approved previously by the Director of the Federal Register as of January 2, 1997 (61 FR 63707, December 2, 1996). Copies may be obtained from Pratt & Whitney, 400 Main St., East Hartford, CT 06108; telephone (860) 565-6600, fax (860) 565-4503. Copies may be inspected at the FAA, New England Region, Office of the Regional 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. (f) This amendment becomes effective on February 25, 1998.

[[Page 9408]]

Issued in Burlington, Massachusetts, on February 11, 1998. James C. Jones, Assistant Manager, Engine and Propeller Directorate, Aircraft Certification Service. [FR Doc. 98-4408 Filed 2-24-98; 8:45 am] BILLING CODE 4910-13-U