02-3668. Airworthiness Directives; Pratt & Whitney Models JT8D-209, -217, -217A, -217C and -219 Turbofan Engines

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The Federal Aviation Administration (FAA) proposes to supersede an existing airworthiness directive (AD), that is applicable to Pratt & Whitney JT8D models -209, -217, -217A, -217C and -219 turbofan engines. That AD currently requires initial and repetitive fluorescent magnetic particle inspections or fluorescent penetrant inspections of the combustion chamber outer case (CCOC) for cracks, and, if necessary, replacement with serviceable parts. Also, that AD requires a one-time boss material verification, and, if necessary, replacement with serviceable parts. Finally, that AD requires replacement of CCOC's with welded-on bosses with improved, one-piece CCOC's. This proposal would require lower initial inspection thresholds for all CCOC's installed in any JT8D model -209, -217, -217A, -217C or -219 turbofan engine. This proposal is prompted by reports of cracked CCOC's that had accumulated fewer cycles in service than the initial inspection thresholds required by the current AD. Also, a CCOC part number was discovered with incorrect material not identified by serial number in PW JT8D ASB 6359. The actions specified by the proposed AD are intended to prevent uncontained failure of the CCOC, which could cause release of debris, damage to the airplane, or fire.

DATES:

Comments must be received by April 15, 2002.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 99-NE-32-AD, 12 New England Executive Park, Burlington, MA 01803-5299. Comments may be inspected at this location, by appointment, between 8 a.m. and 4:30 p.m., Monday through Friday, except Federal holidays. Comments may also be sent via the Internet using the following address: [e-mail]. Comments sent via the Internet must contain the docket number in the subject line.

The service information referenced in the proposed rule may be obtained from Pratt & Whitney, 400 Main St., East Hartford, CT 06108; telephone [phone], fax [phone]. This information may be examined, by appointment, at the Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, 12 New England Executive Park, Burlington, MA.

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 [phone], fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed 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 above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this action may be changed in light of the comments received.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed 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 summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this action must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 99-NE-32-AD.” The postcard will be date stamped and returned to the commenter.

Availability of NPRM's

Any person may obtain a copy of this NPRM by submitting a request to the FAA, New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 99-NE-32-AD, 12 New England Executive Park, Burlington, MA 01803-5299.

Discussion

On December 8, 1999, the Federal Aviation Administration (FAA) issued airworthiness directive (AD) 99-26-06, Amendment 39-11465 (64 FR 71280, December 21, 1999), to require initial and repetitive fluorescent magnetic particle inspections or fluorescent penetrant inspections of the combustion chamber outer case (CCOC) for cracks, and, if necessary, replacement with serviceable parts. Also, that AD requires a one-time boss material verification, and, if necessary, replacement with serviceable parts. Finally, that AD requires replacement of CCOC's with welded-on bosses with improved, one-piece CCOC's. That action was prompted by a report of an uncontained engine failure caused by fatigue cracks originating at the weld joining the drain boss to the CCOC. That condition, if not corrected, could result in CCOC cracks, which could result in an uncontained engine failure and damage to the airplane.

Since that AD was issued, the FAA has received reports of cracked CCOC's that had accumulated fewer cycles in service than the initial inspection thresholds defined in PW JT8D ASB 6359. Also, a CCOC part number (P/N), 797707, was found with incorrect material that was not identified by serial number in PW ASB JT8D ASB 6359. As a result, PW JT8D ASB 6359 was revised on July 31, 2000, to lower the initial inspection threshold from 15,000 cycles in service (CIS) for P/N 500238-01; 18,000 CIS for all other P/N's installed in JT8D-209, -217, -217A, and -217C engines; and 15,000 CIS for all other P/N's installed in JT8D-219 engines to 12,000 CIS for all P/N's installed in any engine. Also, the revision to PW ASB JT8D ASB A6359 expands the serial number list of P/N 797707 cases to include all CCOC's manufactured with that part number. Some minor editorial revisions to PW JT8D ASB A6359, Revision 1, were subsequently made on August 31, 2001. PW JT8D SB 6291, Revision 2, was also revised to reflect the lower thresholds for inspection and replacement of CCOC's.

Manufacturer's Service Information

The FAA has reviewed and approved the technical contents of PW JT8D ASB No. A6359, Revision 2, dated July 31, 2000; and PW JT8D ASB A6359, Revision 3, dated August 31, 2001, that describe procedures and intervals for inspecting CCOC's for cracks and incorrect material, and PW Service Bulletin (SB) No. 6291, Revision 3, dated August 31, 2001, that describes procedures for installation of CCOC P/N 815556.

FAA's Determination of an Unsafe Condition and Proposed Actions

Since an unsafe condition has been identified that is likely to exist or develop on other Pratt & Whitney JT8D models -209, -217, -217A, -217C and -219 turbofan engines of this same type design, the proposed AD would supersede AD 99-26-06 to require, for PW models JT8D-209, -217, -217A, -217C and -219 engines, inspections and replacement of CCOC's at the lower inspection thresholds and the expanded serial number lists outlined in PW JT8D ASB 6359, Revision 3, dated August 31, 2001; and SB 6291, Revision 2, dated August 31, 2001. The actions are required to be done in accordance with the service bulletins described previously.

Economic Analysis

There are approximately 2,624 engines of the affected design in the worldwide fleet. The FAA estimates that 1,280 engines installed on airplanes of U.S. registry are affected by the current AD and that number would remain the same under this proposed AD. The FAA also estimates that it takes approximately 2.5 work hours per engine to accomplish the required inspections, that the average labor rate is $60 per work hour, and those estimates would not change for the proposed AD. The cost of the required parts has increased since the current AD was issued, and would now cost approximately $46,910 per engine. Based on these figures, the updated total cost impact of the proposed superseding AD on U.S. operators is estimated to be $60,236,800.

Regulatory Analysis

This proposed rule does not have federalism implications, as defined in Executive Order 13132, because it would 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. Accordingly, the FAA has not consulted with state authorities prior to publication of this proposed rule.

For the reasons discussed above, I certify that this proposed regulation (1) is not a “significant regulatory action” under Executive Order 12866; (2) is not a “significant rule” under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated, 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. A copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 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.

§ 39.13

[Amended]

2. Section 39.13 is amended by removing Amendment 39-11465, (64 FR 71280), and by adding a new airworthiness directive:

Pratt & Whitney: Docket No. 99-NE-32-AD. Supersedes AD 99-26-06, Amendment 39-11465.

Applicability

This airworthiness directive (AD) is applicable to Pratt & Whitney (PW) models JT8D-209, -217, -217A, -217C, and -219 turbofan engines with combustion chamber outer case (CCOC), part numbers (P/N's) 5000238-01, 797707, 807684, and 815830 installed. These engines are installed on but not limited to McDonnell Douglas MD-80 series airplanes.

Note 1:

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 request approval for an alternative method of compliance in accordance with paragraph (f) 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

Compliance with this AD is required as indicated, unless already done.

To prevent uncontained failure of the CCOC, which could cause release of debris, damage to the airplane, or fire, do the following:

Inspections

(a) Perform initial and repetitive fluorescent magnetic particle inspections (FMPI) or fluorescent penetrant inspections (FPI) of drain bosses and Ps4 bosses of the CCOC for cracks, and, if necessary, replace with serviceable parts before further flight, in accordance with the procedures and intervals specified in paragraph 1.A. of the Accomplishment Instructions of PW JT8D Alert Service Bulletin (ASB) A6359, Revision 3, dated August 31, 2001.

(b) For all CCOC's P/N 797707 inspect for proper Ps4 and drain boss material, and, if necessary, replace with serviceable parts before further flight, in accordance with the procedures and intervals specified in paragraph 1.B. of the Accomplishment Instructions of PW JT8D ASB A6359, Revision 3, dated August 31, 2001.

Effective Date for Computing Compliance Intervals

(c) Use the effective date of this AD for computing compliance intervals whenever PW JT8D ASB A6359, Revision 3, dated August 31, 2001, refers to the publication date of the ASB.

Terminating Action

(d) At the next part accessibility after the effective date of this AD when the CCOC has accumulated cycles-in-service greater than the initial inspection threshold specified in Table 1 of PW JT8D ASB A6359, Revision 3, dated August 31, 2001, replace the CCOC with a one-piece machined CCOC assembly, P/N 815556, in accordance with PW JT8D Service Bulletin (SB) 6291, dated May 20, 1997, or Revision 1 dated July 9, 1997, or Revision 2, dated August 27,1999, or Revision 3 dated August 31, 2001. Installation of an improved, one-piece CCOC, P/N 815556, constitutes terminating action to the inspections required by this AD.

Definition

(e) For the purpose of this AD, part accessibility is defined as an engine disassembly in which the CCOC is removed from the engine.

Alternative Methods of Compliance

(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 (ECO). Operators must submit their request through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, ECO.

Note 2:

Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the ECO.

Special Flight Permits

(g) Special flight permits may be issued in accordance with §§ 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be done.

Issued in Burlington, Massachusetts, on February 7, 2002.

Francis A Favara,

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