AD 2000-26-06

This amendment supersedes an existing airworthiness directive (AD) that applies to Eurocopter Deutschland GMBH (ECD) Model MBB-BK 117 helicopters. That AD currently requires, before further flight, creating a component log card or equivalent record and determining the calendar age and number of flights on each tension-torsion (TT) strap. This amendment establishes a life limit for certain main rotor TT straps. This amendment is prompted by an accident in which a main rotor blade (blade) separated from an ECD Model MBB-BK 117 helicopter due to fatigue failure of a TT strap. The actions specified by this AD are intended to prevent fatigue failure of a TT strap, loss of a blade, and subsequent loss of control of the helicopter.

Final rule

2000-26-06 EUROCOPTER DEUTSCHLAND GMBH: Amendment 39-12056. Docket No. 99- SW-67-AD. Supersedes AD 2000-01-11, Amendment 39-11509, Docket No. 99-SW-60-AD.
Applicability: Model MBB-BK 117 A-1, A-3, A-4, B-1, B-2, and C-1 helicopters, 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 (d) 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, unless accomplished previously.

To prevent fatigue failure of a tension-torsion (TT) strap, loss of a main rotor blade (blade), and subsequent loss of control of the helicopter, accomplish the following:

(a) Before further flight,

(1) Remove TT straps, P/N 2604067 (Bendix) or J17322-1 (Lord), from service or re- identify them as P/N 117-14110 or 117-14111, respectively, in accordance with the Accomplishment Instructions, paragraph 2.B.1.2., Eurocopter Deutschland GMBH Alert Service Bulletin MBB-BK- 117 No. ASB-MBB-BK 117-10-120, Revision 1, dated August 31, 1999 (ASB). TT straps, P/N 2604067 (Bendix) or J17322-1 (Lord), are no longer eligible for installation.

(2) Create a component log card or equivalent record for each TT strap.

(3) Review the history of the helicopter and each TT strap. Determine the age since initial installation on any helicopter (age) and the number of flights oneach TT strap. Enter both the age and the number of flights for each TT strap on the component log card or equivalent record. When the number of flights is unknown, multiply the number of hours time-in-service (TIS) by 5 to determine the number of flights.

(4) Remove any TT strap from service if the total hours TIS or number of flights and age cannot be determined.

(b) Before further flight, remove any TT strap, part number (P/N) 117-14110 or 117-14111, that has been in service 120 months since initial installation on any helicopter or accumulated 25,000 flights (a flight is a takeoff and a landing). Replace the TT strap with an airworthy TT strap.

(c) This AD revises the Airworthiness Limitations Section of the maintenance manual by establishing a life limit for the TT strap, P/N 117-14110 and 117-14111, of 120 months or 25,000 flights, whichever occurs first.

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

(e) 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.

(f) The modification shall be done in accordance with the Accomplishment Instructions, paragraph 2.B.1.2., Eurocopter Deutschland GMBH Alert Service Bulletin MBB-BK-117 No. ASB- MBB-BK 117-10-120, Revision 1, dated August 31, 1999. 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.

(g) This amendment becomes effective on February 26, 2001.

NOTE 3: The subject of this AD is addressed in the Luftfahrt Bundesamt (Federal Republic of Germany) AD 1999-284/2, dated September 1, 1999.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 2000-01-11, Amendment 39-11509 (65 FR 2017, January 13, 2000), which applies to ECD Model MBB-BK 117 helicopters, was published in the Federal Register on September 18, 2000 (65 FR 56275). That action proposed establishing a life limit for the TT straps of 120 months since installation on any helicopter or 25,000 flights, whichever occurs first.

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 127 helicopters of U.S. registry will be affected by this AD, that it will take approximately 16 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 $10,400 per helicopter. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $1,442,720.

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 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 removing Amendment 39-11509 (65 FR 2017, January 13, 2000), and by adding a new airworthiness directive (AD), Amendment 39-12056, to read as follows: