AD 2003-20-11

This amendment supersedes an existing airworthiness directive (AD) for Eurocopter Deutschland GmbH (ECD) Model EC135 P1 and EC135 T1 helicopters. That AD currently requires adding the AD or a statement to the Rotorcraft Flight Manual (RFM) informing the pilot to reduce power and land as soon as practicable if a thump-like sound followed by unusual vibration occurs during flight. That AD also requires visually inspecting the main rotor drive torque strut assembly (strut) for a crack or a break, recording the inspections in the historical or equivalent record, and re-marking and relocating the strut, as appropriate, and replacing any unairworthy strut with an airworthy strut. Also, that AD establishes life limits for certain struts and revises the life limit for other struts. This amendment retains the same requirements but adds the ECD Model EC135 P2 and EC135 T2 helicopters to the applicability and requires replacing certain life-limited struts with titanium struts. This amendment is prompted by the manufacture of a titanium strut that provides a permanent correction to the unsafe condition that led to limiting the life of other struts that have failed. The actions specified by this AD are intended to prevent failure of a strut and subsequent loss of control of the helicopter.

Final rule.

2003-20-11 Eurocopter Deutschland GmbH: Amendment 39-13329, Docket No. 2003-SW-08-AD. Supersedes AD 2001-18-13, Amendment 39-12439, Docket No. 2001-SW-19-AD.

Applicability: Model EC135 P1, P2, T1, and T2 helicopters, with main rotor drive torque strut assembly (strut), part number (P/N) L633M1001 103 or L633M1001 105, installed, certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent failure of the strut and subsequent loss of control of the helicopter, accomplish the following:

(a) Before further flight, insert a copy of this AD or a statement into the Emergency Procedures Section of the Rotorcraft Flight Manual (RFM) to inform the pilot to reduce power and land as soon as practicable if a thump-like sound followed by unusual vibration occurs during flight.

(b) Within 10 hours time-in-service (TIS), visually inspect each strut with 950 or more hours TIS for a crack or a break using a flashlight and a mirrorin accordance with the Accomplishment Instructions, paragraph 3.B.(1) and 3.B.(2), of Eurocopter Alert Service Bulletin EC135-63A-002, Revision 2, dated June 26, 2002 (ASB). Replace any cracked or broken strut with an airworthy strut before further flight.

(c) Inspect the following struts for a crack or a break, using a 6-power or higher magnifying glass, and re-mark and relocate each strut in accordance with the Accomplishment Instructions, paragraph 3.C., of the ASB. This AD does not require you to return any part to the manufacturer.

(1) For a strut with less than 950 hours TIS, inspect before accumulating 1000 hours TIS.

(2) For a strut with 950 or more hours TIS, inspect within 50 hours TIS.

(3) Replace any cracked or broken strut with an airworthy strut before further flight.

(d) This AD revises the Airworthiness Limitations section of the maintenance manual by establishing a life limit of 1000 hours TIS for each strut, P/N L633M1001 103 and L633M1001 105, in its original location, with an additional 1000 hours TIS if properly re-marked and relocated (2000 hours total TIS) in accordance with the Accomplishment Instructions, paragraph 3.C.(3) of the ASB.

(e) Record details of the inspections in the historical or equivalent records in accordance with the Accomplishment Instructions, paragraph 3.C.(4) of the ASB.

(f) When a strut, P/N L633M1001 103 or L633M1001 105, reaches its life limit, replace it with a titanium strut, P/N L633M1001 104, which must be used in pairs, one strut on each side of the transmission. The titanium struts have no life limit. After installing a strut, P/N L633M1001 104, adjust the weight and balance by using the weight and moment stated in the Planning Information, paragraph 1.H., of the ASB.

(g) On or before December 31, 2004, replace each strut, P/N L633M1001 103 or L633M1001 105, with a strut, P/N L633M1001 104.

(h) Replacing struts, P/N L633M1001 103 and L633M1001 105, with titanium struts, P/N L633M1001 104, constitutes terminating action for the requirements of this AD.

(i) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Contact the Safety Management Group for information about previously approved alternative methods of compliance.

(j) The inspections and replacement of the struts shall be done in accordance with Eurocopter Deutschland (GmbH) Alert Service Bulletin EC135-63A-002, Revision 2, dated June 26, 2002. The Director of the Federal Register approved the incorporation by reference 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 NorthCapitol Street, NW., suite 700, Washington, DC.

Note: The subject of this AD is addressed in Luftfahrt-Bundesamt (Federal Republic of Germany) AD 2001-107/2, dated September 19, 2002.

A proposal to amend 14 CFR part 39 by superseding AD 2001-18-13, Amendment 39-12439 (66 FR 47878, September 14, 2001), for the specified model helicopters was published in the Federal Register on June 5, 2003 (68 FR 33663). The action proposed retaining the requirements to add the AD or a statement to the Rotorcraft Flight Manual (RFM) informing the pilot to reduce power and land as soon as practicable if a thump-like sound followed by unusual vibration occurs during flight. Also, the action proposed retaining the requirements to visually inspect each strut for a crack or a break; to record the inspections in the historical or equivalent record; to remark and relocate the strut, as appropriate; to replace any unairworthy strut with an airworthy strut; and to establish or revise life limits for certain struts. In addition to the requirements in the current AD, that action proposed adding the ECD Model EC135 P2 and EC135 T2 helicopters to the applicability andreplacing certain life-limited struts with titanium struts.

The Luftfahrt-Bundesamt (LBA), the airworthiness authority for the Federal Republic of Germany, advises that struts, (P/N) L633M1001 103 and L633M1001 105, should not be used beyond December 31, 2004. The LBA advises replacing those struts with torque struts, P/N L633M1001 104, after January 1, 2005.

ECD has issued Alert Service Bulletin EC135-63A-002, Revision 2, dated June 26, 2002 (ASB), which specifies inspecting for a crack, marking strut locations and serial numbers, and transferring the location side of the torque struts or replacing each strut, P/N L633M1001 103 or L633M10001 105, with a torque strut, P/N L633M1001 104, that is anodized and not coated with paint, which have no life limit. The LBA classified this ASB as mandatory and issued AD No. 2001-107/2, dated September 19, 2002, to ensure the continued airworthiness of these helicopters in the Federal Republic of Germany.

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.

On July 10, 2002, the FAA issued a new version of 14 CFR part 39 (67 FR 47997, July 22, 2002), which governs FAA's AD system. This regulation now includes material that relates to special flight permits, alternative methods of compliance, and altered products. This material previously was included in each individual AD. Since this material is included in 14 CFR part 39, we have not included it in this AD action.

The FAA estimates that this AD will affect 50 helicopters of U.S. registry. The AD will take approximately 1/2 work hour for the flashlight and mirror inspection; 2.5 work hours to remark, relocate, and inspect with a magnifying glass; and 1 hour to replace both struts. The average labor rate is $60 per work hour. Required parts will cost approximately $9,696 per helicopter. Based on these figures, we estimate the total cost impact of the proposed AD on U.S. operators to be $496,800.

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 39-12439 (66 FR 47878, September 14, 2001), and by adding a new airworthiness directive (AD), Amendment 39-13329 to read as follows: