03-14136. Airworthiness Directives; Eurocopter Deutschland GmbH Model EC135 P1, P2, T1, and T2 Helicopters

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes superseding an existing airworthiness directive (AD) for Eurocopter Deutschland GmbH (ECD) Model EC135 P1 and EC135 T1 model 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 action would retain the same requirements but would add the ECD Model EC135 P2 and EC135 T2 helicopters to the applicability and would require replacing certain life-limited struts with titanium struts. This proposal 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 the proposed AD are intended to prevent failure of a strut and subsequent loss of control of the helicopter.

DATES:

Comments must be received on or before August 4, 2003.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Office of the Regional Counsel, Southwest Region, Attention: Rules Docket No. 2003-SW-08-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137. You may also send comments electronically to the Rules Docket at the following address: [e-mail]. Comments may be inspected at the Office of the Regional Counsel between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays.

FOR FURTHER INFORMATION CONTACT:

Richard Monschke, Aviation Safety Engineer, FAA, Rotorcraft Directorate, Rotorcraft Standards Staff, Fort Worth, Texas 76193-0110, telephone [phone], fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications should identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments will be considered before taking action on the proposed rule. The proposals contained in this document may be changed in light of the comments received.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their mailed comments submitted in response to this proposal must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket No. 2003-SW-08-AD.” The postcard will be date stamped and returned to the commenter.

Discussion

On September 4, 2001, the FAA issued AD 2001-18-13, Amendment 39-12439 (66 FR 47878, September 14, 2001), to require adding the AD or a statement in the Emergency Procedures section of the 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 inspecting struts, part number (P/N) L633M1001 103 and L633M1001 105; replacing any cracked or broken strut with an airworthy strut before further flight; and recording each inspection in the helicopter's historical or equivalent record. That AD revised the Airworthiness Limitations section of the maintenance manual by establishing life limits for certain struts. That action was prompted by a report of a thump-like sound heard during flight followed by unusual vibrations due to failure of the right-hand (RH) strut between the main transmission and the fuselage. The requirements of that AD are intended to prevent failure of a strut and subsequent loss of control of the helicopter.

Since issuing that AD, 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.

This helicopter model is manufactured in the Federal Republic of Germany and is type certificated for operation in the United States under the provisions of 14 CFR 21.29 and the applicable bilateral agreement. Pursuant to the applicable bilateral agreement, the LBA has kept the FAA informed of the situation described above. The FAA has examined the findings of the LBA, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States.

This previously described unsafe condition is likely to exist or develop on other helicopters of the same type design. Therefore, the proposed AD would supersede AD 2001-18-13 to require the same actions but would add ECD Model EC135 P2 and EC135 T2 helicopters to the applicability. Also, the proposed AD would require replacing each strut, P/N L633M1001 103 or L633M1001 105, upon reaching its life limit with a titanium strut, P/N L633M1001 104, which would constitute terminating action for the requirements of this AD. The titanium strut must be used in pairs, one on each side of the transmission, and may not be used in conjunction with a strut, P/N L633M1001 103 or L633M1001 105. The titanium strut has no life limit. The proposed AD would require a weight and balance adjustment after installing the titanium strut. The proposed AD would also require on or before December 31, 2004, replacing each strut, P/N L633M1001 103 or L633M1001 105, with a strut, P/N L633M1001 104.

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 proposed AD would affect 50 helicopters of U.S. registry. The proposed actions would 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 would 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 proposed herein would 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 proposal would not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that this proposed regulation (1) is not a “significant regulatory action” under Executive Order 12866; (2) is not a “significant rule” under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated, 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 copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 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), to read as follows:

Eurocopter Deutschland GmbH: 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 mirror in 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.

Note:

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

Issued in Fort Worth, Texas, on May 30, 2003.

David A. Downey,

Manager, Rotorcraft Directorate, Aircraft Certification Service.