AD 2000-10-07

This amendment adopts a new airworthiness directive (AD) that applies to Eurocopter Model EC 135 helicopters. This AD requires replacing a certain oil cooler fan splined drive shaft (shaft) with a different airworthy shaft and re-identifying the part numbers on the oil cooler fans. This amendment is prompted by two incidents in which the shaft broke. The actions specified by this AD are intended to prevent failure of the shaft, loss of oil cooling, and a subsequent engine shutdown during flight.

Final rule

2000-10-07 EUROCOPTER DEUTSCHLAND GMBH: Amendment 39-11731. Docket No. 99-SW-05-AD.
Applicability: Model EC 135 helicopters, serial numbers 0005 through 0071, 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 (e) 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 within 50 hours time-in-service, unless accomplished previously.

To prevent failure of an oil cooler fan splined drive shaft (shaft), loss of oil cooling, and a subsequent engine shutdown during flight, accomplish the following:

(a) Replace each shaft, part number (P/N) L 792M3004 225, with an airworthy shaft, P/N L 792M3004 235.

(b) Re-identify the P/N on each oil cooler fan (fan) using a rubber stamp or smudge-proof paint or equivalent as follows:

(1) On the left fan, change the P/N from L 792M3004 102 to L 792M3004 103.

(2) On the right fan, change the P/N from L 792M3005 102 to L 792M3005 103.

(c) Change the P/N on the gearbox component history card or equivalent record to reflect the revised part numbers.

NOTE 2: Eurocopter Alert Service Bulletin No. EC 135-79A-001, dated January 23, 1998, pertains to the subject of this AD.

(d) Replacing the shaft, re-identifying the fans, and recording this on the gearbox component history card or equivalent record constitute terminating actions for the requirements of this AD.

(e) 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 submit their requests through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Regulations Group.

NOTE 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Regulations Group.

(f) 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 helicopter to a location where the requirements of this AD can be accomplished.

(g) This amendment becomes effective on June 21, 2000.

NOTE 4: The subject of this AD is addressed in Luftfahrt-Bundesamt (Federal Republic of Germany) AD No. 1998-109, dated February 26, 1998.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that applies to Eurocopter Model EC 135 helicopters was published in the Federal Register on February 11, 2000 (65 FR 6925). That action proposed to require replacing a certain shaft with a different airworthy shaft and re-identifying the part numbers on the oil cooler fans.

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.

The FAA estimates that 9 helicopters of U.S. registry will be affected by this AD, that it will take approximately 4 work hours per helicopter to replace and re-identify the affected parts and record these actions in the gearbox history card or equivalent record, and that theaverage labor rate is $60 per work hour. The manufacturer has stated in Alert Service Bulletin EC 135-79A-001, dated January 23, 1998, that required parts will be provided at no cost. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $2,160.

The regulations adopted herein will 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. Therefore, it is determined that this final rule does not have federalism implications under Executive Order 13132.

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 substantialnumber 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 FAA, Office of the Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137.

List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, 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: