AD 99-23-17

This amendment adopts a new airworthiness directive (AD), applicable to Eurocopter France Model AS 332C, L, and L1 helicopters, that requires a one-time inspection of the length of the main gearbox epicyclic module upper casing bearing attachment bolts (attachment bolts), and if they exceed a certain length, replacing the epicyclic module to preclude a potential interference between the attachment bolts and the 2nd stage planet gear cage web. This amendment is prompted by a report of interference between the attachment bolts and the second stage planet gear cage web of the epicyclic module in the main gearbox. The actions specified by this AD are intended to prevent failure of the second stage planet gear of the main gearbox, loss of main rotor drive and subsequent loss of control of the helicopter.

Final rule

99-23-17 EUROCOPTER FRANCE: Amendment 39-11413. Docket No. 98-SW-78-AD.
Applicability: Model AS 332C, L, and L1 helicopters, with epicyclic modules, part number 332A32-2007-00 or -01, with serial numbers with the prefix of "M", from 100 through 689 or 3000 through 3048, installed, certificated in any category.

NOTE 1: This AD applies to each helicopter identified in the preceding applicability provision, regardless of whether it has been otherwise modified, altered, or repaired in the area subject to the requirements of this AD. For helicopters 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 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 in paragraph DD of Eurocopter Service Bulletin No. 01.41, dated November 1995 (95-11) (SB), unless accomplished previously.

To prevent failure of the second stage planet gear of the main gearbox, loss of main rotor drive and subsequent loss of control of the helicopter, accomplish the following:

(a) Inspect each main gearbox epicyclic module upper casing bearing attachment bolt (attachment bolt) in accordance with paragraph CC of the SB.

(b) If any attachment bolt length is greater than 53mm (2.086 inches), remove the epicyclic module and replace the epicyclic module with an airworthy epicyclic module before further flight.

(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, Regulations Group, Rotorcraft Directorate, FAA. Operators shall submittheir requests through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Regulations Group.

NOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Regulations Group.

(d) Special flight permits may be in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the helicopter to a location where the requirements of this AD can be accomplished.

(e) The compliance and inspection shall be done in accordance with paragraphs CC and DD of Eurocopter Service Bulletin No. 01.41, dated November 1995 (95-11). 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 American Eurocopter Corporation, 2701 Forum Drive, Grand Prairie, Texas 75053-4005, telephone (972) 641-3460, fax (972)641-3527. Copies may be inspected at the FAA, Office of the Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

NOTE 3: The subject of this AD is addressed in Direction Generale De L'Aviation Civile (France) AD 93-131-051(B)R1, dated January 18, 1998.

(f) This amendment becomes effective on December 21, 1999.

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 Eurocopter France Model AS 332C, L, and L1 helicopters was published in the Federal Register on August 23, 1999 (64 FR 45929). That action proposed to require a one-time inspection of the length of the attachment bolts, and if any exceed 53mm in length, replacing the epicyclic module.

Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were received on the proposal or the FAA's determination of the cost to the public. The FAA has determined that air safety and the public interest require the adoption of the rule as proposed except for two nonsubstantive changes that have been made to paragraph (c) and Note 2 of the AD. In paragraph (c), the NPRM incorrectly states that alternative methods of compliance (AMOC) or adjustments of the compliance time may be approved by the "Manager, Rotorcraft Standards Staff, Rotorcraft Directorate." This is incorrect and has been changed to state that the Manager, Regulations Group, Rotorcraft Directorate, is responsible for approving any AMOC or adjustment of the compliance time. Note 2 of the NPRM states that information concerning the existence of approved AMOC may be obtained from the "Rotorcraft Standards Staff;" this is also incorrect and has been changed to state that information may be obtained from the "Regulations Group." The FAA has determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.

The FAA estimates that 1 helicopter of U.S. registry will be affected by this AD, that it will take approximately 8 work hours per helicopter to accomplish the required actions, and that the average labor rate is $60 per work hour. Required parts will cost approximately $365,235 to replace the epicyclic module, if necessary.The cost of the attachment bolts is $11. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $491, assuming the bolts are the correct length and the epicyclic module does not have to be replaced.

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 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 adding a new airworthiness directive to read as follows: