AD 2000-16-02R1

This amendment revises an existing airworthiness directive (AD), that is applicable to Pratt & Whitney PW4164, PW4168, and PW4168A series turbofan engines. That AD currently requires initial and repetitive torque checks for loose or broken front pylon mount bolts made from INCO 718 material and MP159 material. That AD also requires initial and repetitive visual inspections of the primary mount thrust load path. This amendment requires extension of the cycles accumulated before performing the initial inspection, reduces the frequency of repetitive inspections for MP159 material bolts, and adds a terminating action to the primary mount thrust load path inspections by introducing a new increased durability forward engine mount bearing housing. This amendment is prompted by component testing to assess the low cycle fatigue (LCF) life of the MP159 material bolts and the development of a new design forward engine mount bearing housing that meets the 8,000 flight cycle design intentfor inspection. The actions specified by this AD are intended to prevent front pylon mount bolt and primary mount thrust load path failure, which could result in an engine separating from the airplane.

Final rule.

2000-16-02R1 Pratt & Whitney: Amendment 39-12989. Docket No. 97-ANE-44-AD. Revises AD 2000-16-02, Amendment 39-11856.

Applicability: This airworthiness directive (AD) is applicable to Pratt & Whitney PW4164, PW4168, and PW4168A series turbofan engines, with front pylon mount bolts, part numbers (P/N's) 54T670 or 51U615, installed. These engines are installed on but not limited to Airbus Industrie A330 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 theunsafe 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 front pylon mount bolt and primary mount thrust load path failure, which could result in engine separation from the airplane, do the following:

INCO 718 Material Bolts Torque Checks

(a) Perform initial and repetitive torque checks of INCO 718 material front pylon mount bolts, P/N 54T670, and replace, if necessary, with new bolts, in accordance with the Accomplishment Instructions of PW Alert Service Bulletin (ASB) No. PW4G-100-A71-9, Revision 1, dated November 24, 1997, as follows:

(1) For front pylon mount bolts, P/N 54T670, with fewer than 1,000 cycles-in-service-since-new (CSN) on the effective date of this AD, accomplish the following in accordance with Part (A) of the Accomplishment Instructions of the ASB:

(i) Perform an initial torque check prior to accumulating 1,250 CSN or at the next engine removal for cause, whichever occurs first.

(ii) Thereafter, perform torque checks at intervals of not less than 750 or greater than 1,250 cycles in service (CIS) since last torque check, not to exceed 11,000 CSN.

(2) For front pylon mount bolts, P/N 54T670, with 1,000 or more CSN but less than 5,750 CSN on the effective date of this AD, accomplish the following in accordance with Part (A) of the Accomplishment Instructions of the ASB:

(i) Perform an initial torque check within 250 CIS after the effective date of this AD, or at the next engine removal for any cause, whichever occurs first.

(ii) Thereafter, perform torque checks at intervals of not less than 750 or greater than 1,250 CIS since last torque check, not to exceed 11,000 CSN.

(3) For front pylon mount bolts, P/N 54T670, with 5,750 or more CSN on the effective date of this AD, accomplish the following in accordance with Part (B) of the Accomplishment Instructions of the ASB:

(i) Perform an initial torque check within 250 CIS after the effective date of this AD, or prior to the next engine removal for any cause, whichever occurs first.

(ii) Thereafter, perform torque checks at intervals of not less than 750 or greater than 1,250 CIS since last torque check, not to exceed 11,000 CSN.

(4) Prior to further flight, replace all four bolts in accordance with Part (A), Paragraph 1(D) of the Accomplishment Instructions of the ASB, if any of the bolts are loose or broken.

INCO 718 Material Bolts Life Limit

(b) This AD establishes a new life limit of 11,000 CSN for front pylon mount bolts, P/N 54T670. Except as provided in paragraph (f) of this AD, no front pylon mount bolts, P/N 54T670, may exceed this new life limit after the effective date of this AD.

MP159 Material Bolts Inspections

(c) Perform initial and repetitive torque inspections of front pylon mount bolts, P/N 51U615, in accordance with the Accomplishment Instructions of Pratt & Whitney ASB PW4G-100-A71-20, Revision 1, dated January 15, 2002, as follows:

(1) For front pylon mount bolts with less than 4,100 CSN on the effective date of this AD, perform the initial torque inspection at the earlier of the following:

(i) Before accumulating 4,350 CSN; or

(ii) The next engine removal for any cause.

(2) For front pylon mount bolts with 4,100 or more CSN on the effective date of this AD, perform the initial torque check at the earlier of the following:

(i) Within 250 CIS after the effective date of this AD; or

(ii) The next engine removal for any cause.

(3) Thereafter, perform torque inspections at intervals not to exceed 4,350 CIS since last torque inspection.

(4) Prior to further flight, replace all four bolts, in accordance with Paragraph 1(D) of the Accomplishment Instructions of the ASB, if any are loose or broken.

Primary Mount Thrust Load Path Inspections

(d) Perform initial and repetitive visual inspections of the primary mount thrust load path, in accordance with the Accomplishment Instructions of PW ASB PW4G-100-A71-18, Revision 2, dated January 15, 2002, as follows:

(1) For forward engine mount assemblies with fewer than 1,000 CSN on the effective date of this AD, perform the initial visual inspection at the earlier of the following:

(i) Before accumulating 1,250 CSN; or

(ii) The next engine removal for any cause.

(2) For forward engine mount assemblies with 1,000 or more CSN on the effective date of this AD, perform the initial visual inspection at the earlier of the following:

(i) Within 250 CIS after the effective date of this AD; or

(ii) The next engine removal for any cause.

(3) Thereafter, perform visual inspections at intervals of not less than 750 or greater than 1,250 CIS since last visual inspection.

(4) Prior to further flight, replace all cracked parts with serviceable parts and inspect the primary thrust load path components in accordance with Paragraph 4 of the accomplishment instructions of the SB.

Terminating Action

(e) Replacement of the forward engine mount bearing housing, P/N 59T794 or P/N 54T659 with P/N 52U420 in accordance with Service Bulletin (SB) PW 4G-100-71-22, dated January 15, 2002, constitutes terminating action to the inspection requirements of paragraph (d) of this AD.

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.

Documents That Have Been Incorporated By Reference

(h) The inspections must be done in accordance with the following Pratt & Whitney (PW) alert service bulletins (ASB's) and service bulletin (SB):

Document No.
Pages
Revision
Date
ASB PW4G-100-A71-9
1
1
Nov. 24, 1997.

2
Original
July 31, 1997.

3
1
Nov. 24, 1997.

4-7
Original
July 31, 1997.

8-9
1
Nov. 24, 1997.

10-11
Original
July 31, 1997.
Total Pages: 11

ASB PW4G-100-A71-20
1
1
Jan. 15, 2002.

2
Original
Dec. 9, 1999.

3-5
1
Jan. 15, 2002.

6-7
Original
Dec. 9, 1999.

8
1
Jan. 15, 2002.

9
Original
Dec. 9, 1999.

10
1
Jan. 15, 2002.
Total Pages: 10

ASB PW4G-100-A71-18
1-2
2
Jan. 15, 2002.

3
1
Dec. 9, 1990.

4
2
Jan. 15, 2002.

5-6
Original
Sept. 15, 1999.

7
2
Jan. 15, 2002.

8-12
Original
Sept. 15, 1999.
Total Pages: 12

SB PW4G-100-71-22
All
Original
Jan. 15, 2002.
Total Pages: 8

This incorporation by reference of certain publications was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. The incorporation by reference of PW ASB PW4G-100-A71-9, Revision 1, dated November 24, 1997, was approved by the Director of the Federal Register on October 16, 2000 (65 FR 49730; August 15, 2002).

Copies may be obtained from Pratt & Whitney, 400 Main St., East Hartford, CT 06108; telephone (860) 565-8860; 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.

Effective Date(i) This amendment becomes effective on February 6, 2003.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by revising AD 2000-16-02, Amendment 39-11856 (65 FR 49730, August 15, 2000), which is applicable to Pratt & Whitney PW4164, PW4168, and PW4168A series turbofan engines was published in the Federal Register on September 13, 2002 (67 FR 57987). That action proposed to require an extension of the cycles accumulated before performing the initial inspection for the MP 159 material bolts, reduce the frequency of repetitive inspections for MP159 material bolts, and add a terminating action to the primary mount thrust load path inspections by introducing a new increased durability forward engine mount bearing housing in accordance with Pratt & Whitney alert service bulletins (ASB's) PW4G-100-A71-9, Revision 1, dated November 24, 1997; ASB PW4G-100-A71-20, Revision 1, dated January 15, 2002; ASB PW4G-100-A71-18, Revision 2, dated January 15, 2002; and service bulletin (SB) PW4G-100-A71-22, dated January 15, 2002.

Comments

Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comment received.

One commenter concurs with the proposed AD and states that the proposed AD is consistent with all appropriate PW service bulletins. The FAA agrees.

After careful review of the available data, including the comment noted above, the FAA has determined that air safety and the public interest require the adoption of the rule as proposed. The FAA has determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.

Economic Analysis

There are approximately 226 engines of the affected design in the worldwide fleet. The FAA estimates that 21 engines installed on aircraft of U.S. registry would be affected by this AD. The FAA also estimates that it would take approximately 3 work hours per engine to perform the actions,and that the average labor rate is $60 per work hour. Required parts would cost approximately $19,000 per engine. Based on these figures, the total cost of the AD to U.S. operators is estimated to be $402,780.

Regulatory Analysis

This final 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 final rule.

For the reasons discussed above, I certify that this action (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) 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 final evaluation has been prepared for this action and it 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, 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.

39.13 [Amended]

2. Section 39.13 is amended by removing Amendment 39-11856 (65 FR 49730, August 15, 2000) and by adding a new airworthiness directive, Amendment 39-12989, to read as follows: