Airworthiness Directives; Eurocopter Deutschland GmbH Model EC135 Helicopters

[Federal Register Volume 74, Number 101 (Thursday, May 28, 2009)]
[Rules and Regulations]
[Pages 25394-25396]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E9-12319]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2009-0482; Directorate Identifier 2008-SW-54-AD; 
Amendment 39-15920; AD 2009-11-10]
RIN 2120-AA64


Airworthiness Directives; Eurocopter Deutschland GmbH Model EC135 
Helicopters

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Final rule; request for comments.

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SUMMARY: We are adopting a new airworthiness directive (AD) for 
Eurocopter Deutschland GmbH (Eurocopter) Model EC135 helicopters. This 
AD results from a report of abnormal main rotor blade vibrations on a 
Eurocopter Model EC135 helicopter. This AD also results from mandatory 
continuing airworthiness information (MCAI) issued by the European 
Aviation Safety Agency (EASA), which is the Technical Agent for the 
Member States of the European Community. The MCAI states that an 
operator reported unusual vibrations during the start phase of the main 
rotor blade on one helicopter. The vibrations stopped after the 
application of torque. Subsequent maintenance personnel found that six 
of the eight attachment screws of the lower hub-shaft bearing support 
were loose. This condition was discovered in two additional 
helicopters. Loose screws in the bearing support, if not detected and 
corrected, could result in abnormal main rotor blade vibrations and 
subsequent damage to the main transmission.

DATES: This AD becomes effective on June 12, 2009.
    The incorporation by reference of certain publications is approved 
by the Director of the Federal Register as of June 12, 2009.
    We must receive comments on this AD by July 27, 2009.

ADDRESSES: You may send comments by any of the following methods:
    <bullet> Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting your 
comments electronically.
    <bullet> Fax: (202) 493-2251.
    <bullet> Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590.
    <bullet> Hand Delivery: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays.
    You may get the service information identified in this AD from 
American Eurocopter Corporation, 2701 Forum Drive, Grand Prairie, TX 
75053-4005, telephone (972) 641-3460, fax (972) 641-3527, or at http://www.eurocopter.com.
    Examining the Docket: You may examine the AD docket on the Internet 
at http://www.regulations.gov or in person at the Docket Operations 
office between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains this AD, the economic evaluation, any 
comments received, and other information. The street address for the 
Docket Operations office (telephone (800) 647-5527) is stated in the 
ADDRESSES section of this AD. Comments will be available in the AD 
docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Chinh Vuong, Aviation Safety Engineer, 
FAA, Rotorcraft Directorate, Safety Management Group, Fort Worth, Texas 
76193-0111, telephone (817) 222-5116, fax (817) 222-5961.

SUPPLEMENTARY INFORMATION: 

Discussion

    We recently received a report of abnormal main rotor blade 
vibration on a Eurocopter Model EC135 helicopter. This main rotor blade 
vibration occurred after initial aircraft start, while operating at 
flat pitch, between 8.5 and 25 percent torque and 98.6 percent NR/N2 
speed, and dissipated once the FADEC switches were advanced to FLIGHT. 
The main rotor transmission chip light also illuminated with minimal 
debris found on the chip detectors. During troubleshooting, six of the 
eight main transmission lower hub-shaft bearing support bolts were 
found lying in the bottom of the main transmission case, atop of the 
lower transmission access panel. Only two of the eight bolts remained 
installed, loose in their positions, and the outer race of the roller 
bearing was rotated out of position (cocked). Approximately three weeks 
after that first incident, we received a report that loose bolts were 
discovered on two additional newer helicopters that had not been 
inspected at the time the loose bolts were discovered on the first 
helicopter. Subsequent investigations revealed that screws were not 
properly torqued and vibrations had caused the screws to back-out. 
Loosened screws in the bearing support, if not detected and corrected, 
could result in abnormal main rotor blade vibrations and subsequent 
damage to the main transmission.
    EASA has issued EASA Emergency AD 2008-0175-E, dated September 16, 
2008, to correct an unsafe condition for the Eurocopter Model EC135 
helicopters. The MCAI explains that ``The lower hub-shaft bearing 
consists of a ball bearing and a roller bearing. The outer race of the 
roller bearing is fixed to the housing with screws. Should all 
attachment screws become loose, the outer race of the roller bearing 
might separate, which would constitute an unsafe condition. In such 
case, however, the axial guidance of the rotor hub-shaft would still be 
ensured.'' The MCAI requires inspecting the main transmission 
attachment hardware and installing locking washers. You may obtain 
further information by examining the MCAI and any related service 
information in the AD docket.

Related Service Information

    Eurocopter has issued Alert Service Bulletin EC135-63A-013, 
Revision 2, dated September 12, 2008 (ASB). The ASB specifies checking 
the screws at the lower hub-shaft bearing for correct attachment and 
securing attachment hardware by means of locking washers. The actions 
described in the MCAI are intended to correct the same unsafe condition 
as that identified in the service information.

[[Page 25395]]

FAA's Evaluation and Unsafe Condition Determination

    This product has been approved by the aviation authority of 
Germany, and is approved for operation in the United States. Pursuant 
to our bilateral agreement with Germany, EASA, their Technical Agent, 
has notified us of the unsafe condition described in the MCAI. We are 
issuing this AD because we evaluated all information provided by EASA 
and determined the unsafe condition exists and is likely to exist or 
develop on other helicopters of the same type design.

Differences Between This AD and the MCAI AD

    This AD does not require sending the main transmission to the 
manufacturer and does not refer to the transmission part numbers. Also, 
this AD uses the term ``hours time-in-service'', the MCAI AD uses the 
term ``flight cycles''.

Costs of Compliance

    We estimate that this AD will affect about 189 helicopters of U.S. 
registry. We also estimate that it will take about 8 work-hours to 
inspect and install lock washers, at an average labor rate of $80 per 
work-hour. Required parts will cost about $574 per helicopter ($86 for 
the lock washers and $488 for the required oil). Based on these 
figures, we estimate the cost of this AD on U.S. operators will be 
$229,446 ($1,214 per helicopter).

FAA's Determination of the Effective Date

    An unsafe condition exists that requires the immediate adoption of 
this AD. We find that the risk to the flying public justifies waiving 
notice and comment prior to adoption of this rule because loosened 
screws in the bearing support, if not detected and corrected quickly, 
could result in abnormal main rotor blade vibrations and subsequent 
damage to the main transmission. Therefore, we have determined that 
notice and opportunity for public comment before issuing this AD are 
impracticable and that good cause exists for making this amendment 
effective in fewer than 30 days.

Comments Invited

    This AD is a final rule that involves requirements affecting flight 
safety, and we did not precede it by notice and opportunity for public 
comment. However, we invite you to send us any written data, views, or 
arguments concerning this AD. Send your comments to an address listed 
under the ADDRESSES section of this AD. Include ``Docket No. FAA-2009-
0482; Directorate Identifier 2008-SW-54-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this AD. We will 
consider all comments received by the closing date and may amend this 
AD because of those comments.
    We will post all comments we receive, without change, to http://www.regulations.gov including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive about this AD.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. ``Subtitle VII: Aviation 
Programs,'' describes in more detail the scope of the Agency's 
authority.
    We are issuing this rulemaking under the authority described in 
``Subtitle VII, Part A, Subpart III, Section 44701: General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on product(s) identified in this 
rulemaking action.

Regulatory Findings

    We determined that this AD will not have federalism implications 
under Executive Order 13132. This AD 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, I certify this AD:
    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. 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.
    We prepared an economic evaluation of the estimated costs to comply 
with this AD and placed it in the AD docket.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The FAA amends Sec.  39.13 by adding the following new AD:

2009-11-10 Eurocopter Deutschland GmbH: Amendment 39-15920. Docket 
No. FAA-2009-0482; Directorate Identifier 2008-SW-54-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective on June 
12, 2009.

Other Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Eurocopter Deutschland GmbH (Eurocopter) 
Model EC135 helicopters with a main transmission with a serial 
number of 0001 through 1420 and 1500 through 1749 installed, 
certificated in any category.

Reason

    (d) The mandatory continuing airworthiness information (MCAI) 
states that an operator reported unusual vibrations during the start 
phase of the main rotor blade on one helicopter. The vibrations 
stopped after the application of torque. Subsequently, maintenance 
personnel found that six of the eight attachment screws of the lower 
hub-shaft bearing support were loose. This condition was discovered 
in two additional helicopters. Loose screws in the bearing support, 
if not detected and corrected, could result in abnormal main rotor 
blade vibrations and subsequent damage to the main transmission.

Actions and Compliance

    (e) Within 3 hours time-in-service (TIS) if unusual vibrations 
are detected during the start phase or the shutdown phase when the 
main rotors are not at full operation RPM, or within 50 hours TIS 
after the effective date of this AD, whichever occurs first, do the 
following:
    (1) Remove the lower transmission cover.

    Note 1: You may drain the oil into a clean container so that it 
can be reused.

    (2) Measure the clearance between the outer race and the 
transmission housing at four positions offset by 90[deg] using a 
feeler gauge as depicted in Figure 1 of Eurocopter

[[Page 25396]]

Alert Service Bulletin EC135-63A-013, Revision 02, dated September 
12, 2008 (ASB). If the measured maximum clearance is:
    (i) Less than or equal to 0.1 mm--install locking washers, 
tighten all screws, and re-measure the clearance by following 
paragraphs 3.B.(3) through 3.B.(7) of the ASB.
    (ii) More than 0.1 mm--determine the difference between the 
smallest and the largest clearance and:
    (A) If the difference is less than 0.4 mm--install locking 
washers, tighten all screws, and re-measure the clearance by 
following paragraphs 3.B.(2) through 3.B.(7) of the ASB.
    (B) If the difference is equal to or more than 0.4 mm--replace 
the transmission before further flight with an airworthy 
transmission that has been modified in accordance with paragraph 
3.B. of the ASB.
    (iii) If the re-measured clearances obtained in accordance with 
paragraphs (e)(2)(i) or (e)(2)(ii)(A) of this AD are not less than 
or equal to 0.05 mm, replace the transmission with an airworthy 
transmission that has been modified in accordance with paragraph 
3.B. of the ASB.
    (3) Reinstall the lower transmission cover and replenish the 
transmission oil.

    Note 2: If the transmission oil was drained into a clean 
container, it can be reused. Also, if the O-ring on the lower 
transmission cover is not damaged, it can be reused once.

    (f) After the effective date of this AD, install only main 
transmissions that have been modified in accordance with paragraph 
3.B.(3) of the ASB.

Differences Between This AD and the MCAI AD

    (g) This AD does not require sending the main transmission to 
the manufacturer and does not refer to the transmission part 
numbers. Also, this AD uses the term ``hours time-in-service'', the 
MCAI AD uses the term ``flight cycles''.

Other Information

    (h) The Manager, Safety Management Group, FAA, ATTN: Chinh 
Vuong, Aviation Safety Engineer, FAA, Rotorcraft Directorate, Safety 
Management Group, Fort Worth, Texas 76193-0111, telephone (817) 222-
5116, fax (817) 222-5961 has the authority to approve AMOCs for this 
AD, if requested using the procedures found in 14 CFR 39.19.

Related Information

    (i) European Aviation Safety Agency (EASA) MCAI Emergency AD No. 
2008-0175-E, dated September 16, 2008, contains related information.

Air Transport Association of America (ATA) Tracking Code

    (j) ATA Code 63: Main rotor drive.

Material Incorporated by Reference

    (k) You must use the specified portions of Eurocopter Alert 
Service Bulletin EC135-63A-013, Revision 02, dated September 12, 
2008, to do the actions required.
    (1) The Director of the Federal Register approved the 
incorporation by reference of this service information under 5 
U.S.C. 552(a) and 1 CFR part 51.
    (2) For service information identified in this AD, contact 
American Eurocopter Corporation, 2701 Forum Drive, Grand Prairie, TX 
75053-4005, telephone (972) 641-3460, fax (972) 641-3527, or at 
http://www.eurocopter.com.
    (3) You may review copies at the FAA, Office of the Regional 
Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, 
Texas; or at the National Archives and Records Administration 
(NARA). For information on the availability of this material at 
NARA, call (202) 741-6030, or go to: http://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued in Fort Worth, Texas on May 19, 2009.
Mark R. Schilling,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
 [FR Doc. E9-12319 Filed 5-27-09; 8:45 am]
BILLING CODE 4910-13-P

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