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

[Federal Register Volume 66, Number 179 (Friday, September 14, 2001)]
[Rules and Regulations]
[Pages 47878-47881]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-22946]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-SW-19-AD; Amendment 39-12439; AD 2001-18-13]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) for 
Eurocopter Deutschland GmbH (Eurocopter) Model EC135 P1 and EC135 T1 
helicopters. This action requires, before further flight, adding a copy 
of this AD or a statement to 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. This action also requires visually 
inspecting for a crack or a break in certain main rotor drive torque 
strut (strut) assemblies at specified time intervals and recording 
details of the inspections in the historical or equivalent record. This 
AD also requires re-marking and relocating the strut as appropriate and 
replacing any unairworthy strut assembly with an airworthy strut 
assembly before further flight. Also, this AD establishes a life limit 
of 1000 hours time-in-service (TIS) for certain struts with an 
additional 1000 hours TIS for struts re-marked right-hand (RH) or left-

[[Page 47879]]

hand (LH) before installing in the new location. This amendment is 
prompted by a report of a thump-like sound heard during flight followed 
by unusual vibrations due to failure of the RH strut between the main 
transmission and the fuselage. The actions specified in this AD are 
intended to prevent failure of a strut, failure of a worn or 
ineffective back-up emergency stop, and subsequent loss of control of 
the helicopter.

DATES: Effective October 1, 2001.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of October 1, 2001.
    Comments for inclusion in the Rules Docket must be received on or 
before November 13, 2001.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Office of the Regional Counsel, Southwest Region, 
Attention: Rules Docket No. 2001-SW-19-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].
    The service information referenced in this AD may be obtained from 
American Eurocopter Corporation, 2701 Forum Drive, Grand Prairie, Texas 
75053-4005, telephone (972) 641-3460, fax (972) 641-3527. This 
information may be examined 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.

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: 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 EC 135 
helicopters. The LBA advises of an isolated thump-like sound heard 
during flight followed by unusual vibrations. The inspection following 
this incident revealed that the attachment between the tensile stress-
loaded strut on the RH side of the main transmission and the fuselage 
structure had ruptured. For such cases, the emergency stop, fitted to 
the fuselage structure to provide redundancy backup, takes over or will 
have already taken over the function of the strut. Under such 
conditions, however, there is a danger that the emergency stop could 
become worn and ineffective if it is kept in operation for a long 
period of time with an unairworthy strut.
    Eurocopter has issued Alert Service Bulletin EC135-63A-002, 
Revision 1, dated March 12, 2001 (ASB), which specifies notifying the 
pilots of Model EC 135 helicopters about the contents of the ASB. The 
ASB also specifies inspecting the strut for a crack, marking the strut 
location and serial number (S/N) in the vicinity of the part number (P/
N), and transferring location side of the struts at certain intervals. 
The LBA classified this ASB as mandatory and issued AD 2001-107, dated 
March 13, 2001 to ensure the continued airworthiness of these 
helicopters in the Federal Republic of Germany.
    These helicopter models are manufactured in the Federal Republic of 
Germany and are type certificated for operation in the United States 
under the provisions of 14 CFR 21.29 and the applicable bilateral 
agreement. Pursuant to this 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.
    We have identified an unsafe condition that is likely to exist or 
develop on other Eurocopter Model EC135 P1 and EC135 T1 helicopters of 
the same type designs registered in the United States. Therefore, this 
AD is being issued to prevent failure of a strut and subsequent loss of 
control of the helicopter.
    This AD requires the following for each strut, P/N L633M1001 103 
and L633M1001 105:
    <bullet> Before further flight, insert a copy of this AD or a 
statement into the Emergency Procedures section of the 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.
    <bullet> Within 10 hours TIS, visually inspect each strut with 950 
or more hours TIS for a crack or a break.
    <bullet> Before accumulating 1000 hours TIS for each strut with 
less than 950 TIS and within 50 hours TIS for each strut with 950 or 
more hours TIS, inspect for a crack or a break using a 6-power or 
higher magnifying glass.
    <bullet> Replace any cracked or broken strut with an airworthy 
strut before further flight.
    <bullet> Enter the details of each inspection in the helicopter's 
historical or equivalent record.

This AD revises the Airworthiness Limitations section of the 
maintenance manual by establishing a life limit of 1000 hours TIS for 
each strut in its original location, with an additional 1000 hours TIS 
if properly re-marked and relocated (2000 hours total TIS) to the 
opposite side of the transmission. The additional 1000 hours TIS life 
is possible because the loading mode is changed by relocating the 
tension loaded RH strut to the LH position, which is loaded in 
compression. The actions are required to be accomplished in accordance 
with the service bulletin described previously.
    The short compliance time involved is required because the 
previously described critical unsafe condition can adversely affect the 
controllability and structural integrity of the helicopter. Therefore, 
before further flight, insert a copy of this AD or a statement into the 
Emergency Procedures section of the 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. Also, because visually 
inspecting each strut with 950 or more hours TIS for a crack or break 
is required within 10 hours TIS, and, if a cracked or broken part is 
found, replacing any unairworthy part with an airworthy part is 
required before further flight, this AD must be issued immediately.
    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for prior 
public comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.
    The FAA estimates that 38 helicopters will be affected by this AD. 
The FAA also estimates approximately \1/2\ work hour to do a flashlight 
and mirror inspection and 2.5 work hours to re-mark, relocate, inspect 
with a 6-power or higher magnifying glass, and replace each strut as 
necessary. The average labor rate is $60 per work hour. Required parts 
will cost approximately $2400 per helicopter. Based on these figures, 
the total cost impact of the AD on U.S. operators is estimated to be 
$98,040.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this rule by 
submitting such written data, views, or arguments as they may desire. 
Communications should identify the

[[Page 47880]]

Rules Docket number and be submitted in triplicate to the address 
specified under the caption ADDRESSES. All communications received on 
or before the closing date for comments will be considered, and this 
rule may be amended in light of the comments received. Factual 
information that supports the commenter's ideas and suggestions is 
extremely helpful in evaluating the effectiveness of the AD action and 
determining whether additional rulemaking action would be needed.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the rule. All comments submitted will be 
available in the Rules Docket for examination by interested persons. A 
report that summarizes each FAA-public contact concerned with the 
substance of this AD will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their mailed 
comments submitted in response to this rule must submit a self-
addressed, stamped postcard on which the following statement is made: 
``Comments to Docket No. 2001-SW-19-AD.'' The postcard will be date 
stamped and returned to the commenter.
    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.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and that it is not a ``significant regulatory 
action'' under Executive Order 12866. It has been determined further 
that this action involves an emergency regulation under DOT Regulatory 
Policies and Procedures (44 FR 11034, February 26, 1979). If it is 
determined that this emergency regulation otherwise would be 
significant under DOT Regulatory Policies and Procedures, a final 
regulatory evaluation will be prepared and placed in the Rules Docket. 
A copy of it, if filed, 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.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding a new airworthiness directive 
to read as follows:

2001-18-13  Eurocopter Deutschland GmbH Amendment 39-12439. Docket 
No. 2001-SW-19-AD.

    Applicability: Model EC135 P1 and EC135 T1 helicopters, with 
main rotor drive torque strut assembly (strut), part number (P/N) 
L633M1001 103 or L633M1001 105, installed, 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 (f) 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 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 
Deutschland GmbH Alert Service Bulletin EC135-63A-002, Revision 1, 
dated March 12, 2001 (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) 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.

    (g) Special flight permits may be issued in accordance with 14 
CFR 21.197 and 21.199 to operate the helicopter to a location where 
the requirements of this AD can be accomplished.
    (h) The inspections, re-marking, relocation, and entry in the 
historical or equivalent record of each strut, P/N L633M1001 103 and 
L633M1001 105, shall be done in accordance with the Accomplishment 
Instructions, paragraphs 3.B.(1), 3.B.(2), and 3.C., of Eurocopter 
Deutschland GmbH Alert Service Bulletin EC135-63A-002, Revision 1, 
dated March 12, 2001. 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.
    (i) This amendment becomes effective on October 1, 2001.

    Note 3: The subject of this AD is addressed in Luftfahrt-
Bundesamt (Federal Republic of Germany) AD 2001-107, dated March 13, 
2001.



[[Page 47881]]


    Issued in Fort Worth, Texas, on September 4, 2001.
David A. Downey,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 01-22946 Filed 9-13-01; 8:45 am]
BILLING CODE 4910-13-U

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