[Federal Register Volume 69, Number 106 (Wednesday, June 2, 2004)]
[Proposed Rules]
[Pages 31051-31053]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-12443]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2003-SW-39-AD]
RIN 2120-AA64


Airworthiness Directives; Eurocopter Deutschland GmbH Model EC135 
P1, P2, T1, and T2 Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes superseding an existing airworthiness 
directive (AD) for Eurocopter Deutschland GmbH (Eurocopter) Model EC135 
P1, P2, T1, and T2 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 an 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, re-marking and relocating the 
strut, as

[[Page 31052]]

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 require the 
same actions as the existing AD except that it proposes to change the 
visual inspection from a one-time inspection to daily inspections; 
reduces the life limit for aluminum struts; and eliminates the once-
only transfer and remarking of certain struts. This proposal is 
prompted by an incident in which a pilot felt an in-flight increase in 
vibration and subsequent discovery of a failed strut. 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 2, 2004.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Office of the Regional Counsel, Southwest Region, 
Attention: Rules Docket No. 2003-SW-39-AD, 2601 Meacham Blvd., Room 
663, Fort Worth, Texas 76137. You may also send comments electronically 
to the Rules Docket at the following address: [email protected]. 
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 (817) 222-5116, fax (817) 222-5961.

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-39-AD.'' The postcard will be date 
stamped and returned to the commenter.

Discussion

    On September 29, 2003, the FAA issued AD 2003-20-11, Amendment 39-
13329 (68 FR 58581, October 10, 2003), Docket 2003-SW-08-AD, to require 
adding the AD or a statement to the RFM informing the pilot to reduce 
power and land as soon as practicable if a thump-like sound followed by 
an unusual vibration occurs during flight. That AD also requires 
visually inspecting the strut for a crack or a break within 10 hours 
time-in-service, recording the inspections in the historical or 
equivalent record, 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.
    Since issuing that AD, there has been another incident in which a 
pilot felt an in-flight increase in vibration. Post-flight examinations 
revealed a fractured aluminum strut.
    The Luftfahrt-Bundesamt (LBA), the airworthiness authority for the 
Federal Republic of Germany, notified the FAA that an unsafe condition 
may exist on Eurocopter Model EC135 P1, P2, T1, and T2 helicopters. The 
LBA advises that the holders of affected aircraft registered in the 
Federal Republic of Germany must carry out the inspection for a crack, 
marking, replacement, and reduction of life limit of struts in 
accordance with the manufacturer's alert service bulletin.
    Eurocopter has issued Alert Service Bulletin EC135-63A-002, 
Revision 4, dated July 7, 2003 (ASB), concerning reduction in life 
limit for the strut, and visual inspections of the strut and emergency 
stop. The ASB contains errors--in paragraph 1.A., the abbreviation ``S/
N'' should be ``P/N'' and in paragraphs 1.C., 1.E.(1), and 1.E.(2), it 
incorrectly states that the ASB is Revision 3 rather than Revision 4. 
The LBA classified this ASB as mandatory and issued AD No. 2001-107/3, 
dated August 21, 2003, to ensure the continued airworthiness of these 
helicopters in the Federal Republic of Germany.
    This previously described unsafe condition is likely to exist or 
develop on other helicopters of the same type designs. Therefore, the 
proposed AD would supersede AD 2003-20-11 and require: adding the AD or 
a statement to 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; visually inspecting the strut for a crack or a 
break before the first flight of each day; replacing any unairworthy 
strut with an airworthy strut; replacing all aluminum struts with 
titanium struts on or before accumulating 500 hours TIS or no later 
than December 31, 2004, whichever occurs first; installing the struts 
in pairs; and canceling the once-only transfer and remarking of certain 
struts.
    The FAA estimates that this proposed AD would affect 50 helicopters 
of U.S. registry, and would take approximately 92.25 work hours per 
helicopter to accomplish the inspections and parts replacement at an 
average labor rate of $65 per work hour. Required parts would cost 
approximately $7,296 per helicopter. Based on these figures, we 
estimate the total cost impact of the proposed AD on U.S. operators to 
be $664,612 to replace the aluminum struts on the entire fleet.
    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 
economic 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.

[[Page 31053]]

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.


Sec.  39.13  [Amended]

    2. Section 39.13 is amended by removing Amendment 39-13329 (68 FR 
58581, October 10, 2003), and by adding a new airworthiness directive 
(AD), to read as follows:

Eurocopter Deutschland GmbH: Docket No. 2003-SW-39-AD. Supersedes AD 
2003-20-11, Amendment 39-13329, Docket No. 2003-SW-08-AD.

    Applicability: Model EC135 P1, P2, T1, and T2 helicopters, with 
main rotor drive aluminum 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, do the following:
    (a) Before further flight, insert a copy of this AD or insert 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 an unusual 
vibration occurs during flight.
    (b) Before the first flight of each day, using a light and 
mirror, inspect each aluminum strut for a crack or a break by 
following the Accomplishment Instructions, paragraph 3.B. of 
Eurocopter Alert Service Bulletin EC135-63A-002, Revision 4, dated 
July 7, 2003 (ASB). Replace any cracked or broken strut with a new 
titanium strut, P/N L633M1001 104, before further flight.
    (c) For each aluminum strut with 400 or more hours TIS, within 
the next 100 hours time-in-service (TIS), replace each aluminum 
strut with a titanium strut, P/N L633M1001 104.
    (d) This AD revises the Airworthiness Limitations section of the 
maintenance manual by reducing the retirement life of each aluminum 
strut, P/N L633M1001 103 and L633M1001 105, to 500 total hours TIS 
or retiring them no later than December 31, 2004, whichever comes 
first.
    (e) The aluminum struts must be replaced with titanium struts in 
pairs and at the same time. Installing one aluminum strut and one 
titanium strut is not authorized. After installing titanium struts, 
recalculate the weight and balance using 0.356 kg as the weight and 
1498.76 kgmm as the moment for both titanium struts.

    Note 1: The once-only transferring and remarking of certain 
aluminum struts provided in the superseded AD are no longer 
authorized.

    (f) Replacing aluminum struts, P/N L633M1001 103 and L633M1001 
105, with titanium struts, P/N L633M1001 104, constitutes 
terminating action for the requirements of this AD. Titanium struts 
have no life limit.
    (g) 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 2: The subject of this AD is addressed in Luftfahrt-
Bundesamt (Federal Republic of Germany) AD 2001-107/3, dated August 
21, 2003.


    Issued in Fort Worth, Texas, on May 21, 2004.
David A. Downey,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 04-12443 Filed 6-1-04; 8:45 am]
BILLING CODE 4910-13-P