AD 95-17-15

This amendment adopts a new airworthiness directive (AD), applicable to General Electric Company (GE) CF6-45/-50 series turbofan engines, that requires an initial and repetitive on-wing visual inspection of the side links of the five-link forward mount assembly for cracks, and replacement of the side links and pylon attachment bolts, and inspection of the fail-safe bolt and platform lug, if the side links are found cracked. This AD also requires a shop-level refurbishment of the side links as a terminating action to the on-wing inspection program. This amendment is prompted by four reports of cracked side links detected during routine engine shop visits. The actions specified by this AD are intended to prevent a side link fracture, which could result in the failure of the second side link, or the forward engine mount pylon attachment bolts, and possible separation of the engine from the aircraft.

Final rule.

95-17-15 General Electric Company: Amendment 39-9346. Docket 95-ANE-10.

Applicability: General Electric Company (GE) CF6-45/-50 series turbofan engines installed on, but not limited to, Airbus A300 series, Boeing 747 series, and McDonnell Douglas DC-10 series aircraft. NOTE: 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 use the authority provided in paragraph (d) to request approval from the Federal Aviation Administration (FAA). This approval may address either no action, if the current configuration eliminates the unsafe condition, or different actions 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 a side link fracture, which could result in failure of the second side link, or the forward engine mount pylon attachment bolts, and possible separation of the engine from the aircraft, accomplish the following:

(a) Inspect left-hand side links, Part Numbers (P/N) 9204M94P01, 9204M94P03, and 9346M99P01, and right-hand side links, P/N's 9204M94P02, 9204M94P04, and 9346M99P02, that have not had the side link refurbishment done in accordance with GE CF6-50 Task Numbered Shop Manual, GEK 50481, Chapter 72-23-11, including Temporary Revision No. 72-0821 and 72-0822, both dated November 1, 1994, as follows:

(1) For side links that have not been previously inspected inaccordance with GE Aircraft Engines (GEAE) CF6-50 Service Bulletin (SB) No. 72-1092, dated November 18, 1994, inspect in accordance with paragraph 2.A of GEAE CF6-50 SB No. 72-1092, dated November 18, 1994, prior to accumulating 350 cycles in service (CIS), or 750 hours time in service (TIS), after the effective date of this AD, whichever occurs earlier.

(2) For side links that have been previously inspected in accordance with GEAE CF6- 50 SB No. 72-1092, dated November 18, 1994, inspect in accordance with paragraph 2.A of GEAE CF6-50 SB No. 72-1092, dated November 18, 1994, prior to accumulating 350 CIS, or 750 hours TIS since inspected in accordance with GEAE CF6-50 SB No. 72-1092, dated November 18, 1994, whichever occurs earlier.

(3) Thereafter, inspect in accordance with paragraph 2.A of GEAE CF6-50 SB No. 72-1092, dated November 18, 1994, at intervals not to exceed 350 CIS, or 750 hours TIS since the last inspection, whichever occurs earlier.
(4) If side links arefound cracked, replace the cracked side links and pylon attachment bolts with serviceable parts, and inspect the fail-safe bolt and platform lug in accordance with paragraph 2.B of GEAE CF6-50 SB No. 72-1092, dated November 18, 1994, prior to further flight.

(b) Refurbish the left-hand and right-hand side links identified in paragraph (a) of this AD at the next engine shop visit after the effective date of this AD in accordance with paragraph 2.C of GEAE CF6-50 SB No. 72-1092, dated November 18, 1994. Refurbishment of side links in accordance with this paragraph constitutes terminating action to the on-wing inspection requirements of paragraph (a) of this AD.

(c) For the purpose of this AD, an engine shop visit is defined as the induction of an engine into a shop for maintenance involving the separation of the fan and core modules.

(d) 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.

(e) The actions required by this AD shall be done in accordance with the following service bulletin:

Document No.
Pages
Date
GEAE CF6-50
SB No. 72-1092
1-7
November 18, 1994
Total Pages: 7.

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 General Electric Aircraft Engines, CF6 Distribution Clerk, Room 132, 111 Merchant Street, Cincinnati, OH 45246. 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.

(f) This amendment becomes effective on October 10, 1995.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to General Electric Company (GE) CF6-45/-50 series turbofan engines was published in the Federal Register on April 6, 1995 (60 FR 17487). That action proposed to require an initial and repetitive on-wing visual inspection of the side links of the five-link forward mount assembly for cracks, and replacement of the side links and pylon attachment bolts, and inspection of the fail-safe bolt and platform lug, if side links are found cracked. That proposal also would require a shop-level refurbishment of the side links as a terminating action to the on-wing inspection program. The actions would be required to be accomplished in accordance with GE Aircraft Engines CF6-50 Service Bulletin No. 72-1092, dated November 18, 1994.

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

The one commenter states that the requirement to refurbish the side link at the next engine shop visit after effective date of the AD identified in paragraph (b) should be extended so that their current maintenance program is not disrupted. The commenter further feels that the initial and repetitive inspection program will be sufficient to meet the safety objectives of the AD, and therefore considers the refurbishment to be optional. The FAA does not concur. The FAA has determined that the refurbishment compliance schedule fairly and reasonably balances the safety need to eliminate the unsafe condition from the fleet as quickly as possible with the operators' need to avoid unscheduled maintenance actions. The initial and repetitive inspections were intended as an interim corrective action only, and in order to meet the safety objectives of the AD, the refurbishment was deemed necessary. Individual operatorswho believe their circumstances warrant relief from the compliance schedule may submit requests for alternative methods of compliance or adjustments to the compliance times.

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 estimates that 220 engines installed on aircraft of U.S. registry will be affected by this AD, that it will take approximately 7.5 work hours per engine to accomplish the required actions, and that the average labor rate is $60 per work hour. The FAA has estimated that only a small percentage of parts will actually require replacement as a result of this AD, and therefore, has determined the parts cost to be negligible. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $99,000.

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.

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 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 from the Rules Docket at the location provided under the caption "ADDRESSES." List of Subjects in14 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 USC 106(g), 40101, 40113, 44701. 39.13 - [AMENDED]

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