[Federal Register Volume 71, Number 73 (Monday, April 17, 2006)]
[Proposed Rules]
[Pages 19663-19666]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-5646]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-21242; Directorate Identifier 2005-NE-09-AD]
RIN 2120-AA64


Airworthiness Directives; Turbomeca Arriel 1B, 1D, 1D1, and 1S1 
Turboshaft Engines

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

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to revise an existing airworthiness directive 
(AD) for certain Turbomeca Arriel 1B, 1D, 1D1, and 1S1 turboshaft 
engines. That AD currently requires initial and repetitive position 
checks of the gas generator 2nd stage turbine blades on all Turbomeca 
Arriel 1B, 1D, 1D1, and 1S1 turboshaft engines. That AD also currently 
requires initial and repetitive replacements of 2nd stage turbines on 
1B, 1D, and 1D1 engines only. This proposed AD revision would require 
the same actions, but would relax the compliance times for initially 
replacing 2nd stage turbines in Arriel 1B, 1D, and 1D1 turboshaft 
engines. This proposed AD revision results from a request by Turbomeca 
to clarify the compliance times for 2nd stage turbine initial 
replacement on Arriel 1D, 1D1, and 1B turboshaft engines. We are 
proposing this AD revision to clarify and relax the AD compliance times 
for 2nd stage turbine initial replacement on Arriel 1B, 1D, and 1D1 
turboshaft engines. We are also proposing this AD revision to prevent 
inflight engine shutdown and subsequent forced autorotation landing or 
accident.

DATES: We must receive any comments on this proposed AD revision by 
June 16, 2006.

ADDRESSES: Use one of the following addresses to comment on this 
proposed AD revision.
     DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility; U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, 
Washington, DC 20590-0001.
     Fax: (202) 493-2251.
     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    Contact Turbomeca, 40220 Tarnos, France; telephone +33 05 59 74 40 
00, fax +33 05 59 74 45 15, for the service information identified in 
this proposed AD revision.

FOR FURTHER INFORMATION CONTACT: Christopher Spinney, Aerospace 
Engineer, Engine Certification Office, FAA, Engine and Propeller 
Directorate, 12 New England Executive Park, Burlington, MA 01803; 
telephone (781) 238-7175, fax (781) 238-7199.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments regarding this proposal. Send your comments to an address 
listed under ADDRESSES. Include ``Docket No. FAA-2005-21242; 
Directorate Identifier 2005-NE-09-AD'' in the subject line of your 
comments. We specifically invite comments on the overall regulatory,

[[Page 19664]]

economic, environmental, and energy aspects of the proposed AD. We will 
consider all comments received by the closing date and may amend the 
proposed AD in light of those comments.
    We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this proposed AD. Using the search function of the 
DMS Web site, anyone can find and read the comments in any of our 
dockets, including the name of the individual who sent the comment (or 
signed the comment on behalf of an association, business, labor union, 
etc.). You may review the DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR 19477-78) or you 
may visit http://dms.dot.gov.

Examining the AD Docket

    You may examine the docket that contains the proposal, any comments 
received and any final disposition in person at the DMS Docket Office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The Docket Office (telephone (800) 647-5227) is located on 
the plaza level of the Department of Transportation Nassif Building at 
the street address stated in ADDRESSES. Comments will be available in 
the AD docket shortly after the DMS receives them.

Discussion

    On January 12, 2006, the FAA issued AD 2006-02-08, Amendment 39-
14460 (71 FR 3754, January 24, 2006). The Direction Generale de 
L'Aviation Civile (DGAC), which is the airworthiness authority for 
France, notified the FAA that an unsafe condition might exist on 
Turbomeca, Arriel 1B (modified per TU 148), 1D, 1D1, and 1S1 turboshaft 
engines. The DGAC advises that sixteen cases of release of gas 
generator 2nd stage turbine blades occurred in service, with full 
containment of debris. These events resulted in uncommanded engine in 
flight shutdowns. Although terminating action is still unavailable, 
mandatory checks of the turbine blades and replacement of the turbine 
are being required in order to reduce the probability of an uncommanded 
engine in flight shutdown. That AD requires initial and repetitive 
position checks of the gas generator 2nd stage turbine blades on all 
Turbomeca Arriel 1B, 1D, 1D1, and 1S1 turboshaft engines. That AD also 
requires initial and repetitive replacements of 2nd stage turbines on 
1B, 1D, and 1D1 engines only. That condition, if not corrected, could 
result in uncommanded engine in flight shutdown.

Actions Since AD 2006-02-08 Was Issued

    Since that AD 2006-02-08 was issued, Turbomeca asks if our intent 
is to require initial replacement of all Arriel 1B, 1D, and 1D1 2nd 
stage turbines by August 31, 2006. Turbomeca states that if so, the 
compliance time in the AD is too restrictive. Turbomeca requests that 
we clarify the AD compliance times for 2nd stage turbine initial 
replacement on Arriel 1B, 1D, and 1D1 turboshaft engines.
    We recognize that our intent is not clear in the AD. Our intent is 
not to require all Arriel 1D, 1D1, and 1B 2nd stage turbine initial 
replacements by August 31, 2006. Our intent is to require initial 
replacement of only those Arriel 1B, 1D, and 1D1 2nd stage turbines 
that are over the hourly limits specified. We are proposing this AD 
revision to clarify and relax the AD compliance times for 2nd stage 
turbine initial replacement on Arriel 1B, 1D, and 1D1 turboshaft 
engines. We are also proposing this AD revision to prevent inflight 
engine shutdown and subsequent forced autorotation landing or accident.

Relevant Service Information

    We have reviewed and approved the technical contents of Turbomeca 
Alert Service Bulletins (ASBs) A292 72 0807, for Arriel 1B post-TU 148; 
ASB A292 72 0808, for Arriel 1D; ASB A292 72 0809, for Arriel 1D1; and 
ASB A292 72 0810, for Arriel 1S1, all dated March 24, 2004. These ASBs 
describe procedures for initial and repetitive position checks of the 
2nd stage turbine blades, and replacement of 2nd stage turbines on 1B 
and 1D1 engines only. The DGAC classified these ASBs as mandatory and 
issued airworthiness directive F-2004-047, dated March 31, 2004, in 
order to ensure the airworthiness of these Turbomeca Arriel 1B, 1D, 1D1 
and 1S1 turboshaft engines in France.

Bilateral Agreement Information

    This engine model is manufactured in France and is type 
certificated for operation in the United States under the provisions of 
section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and 
the applicable bilateral airworthiness agreement. In keeping with this 
bilateral airworthiness agreement, the DGAC kept us informed of the 
situation described above. We have examined the findings of the DGAC, 
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.

FAA's Determination and Requirements of the Proposed AD Revision

    We have evaluated all pertinent information and identified an 
unsafe condition that is likely to exist or develop on other products 
of this same type design. We are proposing this AD revision, which 
would require:
     Initial and repetitive position checks of the 2nd stage 
turbine blades on Turbomeca Arriel 1B, 1D, 1D1, and 1S1 turboshaft 
engines.
     Replacement of 2nd stage turbines on 1B and 1D1 engines 
only.
     Initially replacing 2nd stage turbines in Arriel 1B, 1D, 
and 1D1 turboshaft engines at relaxed compliance times.
    The proposed AD revision would require that you do these actions 
using the service information described previously.

Costs of Compliance

    We estimate that this proposed AD revision would affect 721 engines 
installed on helicopters of U.S. registry. We also estimate that it 
would take about 2 workhours per engine to inspect all 721 engines and 
40 workhours per engine to replace about 571 2nd stage turbines on 1B 
and 1D1 engines, and that the average labor rate is $80 per work hour. 
Required parts would cost about $3,200 per engine. Based on these 
figures, we estimate the total cost of the proposed AD revision to U.S. 
operators to be $4,249,760.

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 products identified in this 
rulemaking action.

[[Page 19665]]

Regulatory Findings

    We have determined that this proposed AD revision would not have 
federalism implications under Executive Order 13132. This proposed AD 
revision 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.
    For the reasons discussed above, I certify that the 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. Would 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 a regulatory evaluation of the estimated costs to 
comply with this proposed AD revision. See the ADDRESSES section for a 
location to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 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. The FAA amends Sec.  39.13 by removing Amendment 39-14460 (71 FR 
3754, January 24, 2006) and by adding a new airworthiness directive, to 
read as follows:

Turbomeca: Docket No. FAA-2005-21242; Directorate Identifier 2005-
NE-09-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this airworthiness directive (AD) action by June 16, 
2006.

Affected ADs

    (b) This AD revises AD 2006-02-08, Amendment 39-14460.

Applicability

    (c) This AD revision applies to Turbomeca Arriel 1B engines 
fitted with 2nd stage turbine modification TU 148, and Arriel 1D, 
1D1, and 1S1 engines. Arriel 1B engines are installed on, but not 
limited to, Eurocopter France AS-350B and AS-350A ``Ecureuil'' 
helicopters. Arriel 1D engines are installed on, but not limited to, 
Eurocopter France AS-350B1 ``Ecureuil'' helicopters. Arriel 1D1 
engines are installed on, but not limited to, Eurocopter France AS-
350B2 ``Ecureuil'' helicopters. Arriel 1S1 engines are installed on, 
but not limited to, Sikorsky Aircraft S-76A and S-76C helicopters.

Unsafe Condition

    (d) This AD revision results from a request by Turbomeca to 
clarify the compliance times for 2nd stage turbine initial 
replacement on Arriel 1B, 1D, and 1D1 turboshaft engines. We are 
issuing this AD revision to clarify and relax the AD compliance 
times for 2nd stage turbine initial replacement on Arriel 1B, 1D, 
and 1D1 turboshaft engines. We are also issuing this AD revision to 
prevent inflight engine shutdown and subsequent forced autorotation 
landing or accident.

Compliance

    (e) You are responsible for having the actions required by this 
AD revision performed within the compliance times specified unless 
the actions have already been done.

Initial Relative Position Check of 2nd Stage Turbine Blades

    (f) Do an initial relative position check of the 2nd stage 
turbine blades using the Turbomeca mandatory alert service bulletins 
(ASBs) specified in the following Table 1. Do the check before 
reaching any of the intervals specified in Table 1 or within 50 
hours time-in-service after the effective date of this AD, whichever 
occurs later.

          Table 1.--Initial and Repetitive Relative Position Check Intervals of 2nd Stage Turbine Blade
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                                           Initial relative
        Turbomeca engine model              position check        Repetitive interval    Mandatory alert service
                                               interval                                          bulletin
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Arriel 1B (modified per TU 148)......  Within 1,200 hours time- Within 200 hours time-   A292 72 0807, dated
                                        since-new (TSN) or       in-service-since-last-   March 24, 2004.
                                        time-since-overhaul      relative-position-
                                        (TSO) or 3,500 cycles-   check (TSLRPC).
                                        since-new (CSN) or
                                        cycles-since-overhaul
                                        (CSO), whichever
                                        occurs earlier.
Arriel 1D1 and Arriel 1D.............  Within 1,200 hours TSN   Within 150 hours TSLRPC  A292 72 0809, Update
                                        or TSO or 3,500 hours                             No. 1, dated October
                                        CSN or CSO, whichever                             4, 2005.
                                        occurs earlier.
Arriel 1S1...........................  Within 1,200 hours TSN   Within 150 hours TSLRPC  A292 72 0810, dated
                                        or TSO or 3,500 hours                             March 24, 2004.
                                        CSN or CSO, whichever
                                        occurs earlier.
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Repetitive Relative Position Check of 2nd Stage Turbine Blades

    (g) Recheck the relative position of 2nd stage turbine blades at 
the TSLRPC intervals specified in Table 1 of this AD, using the 
mandatory ASBs indicated.

Credit for Previous Relative Position Checks

    (h) Relative position checks of 2nd stage turbine blades done 
using Turbomeca Service Bulletin A292 72 0263, Update 1, 2, 3, or 4, 
may be used to show compliance with the initial requirements of 
paragraph (f) of this AD.

Initial Replacement of 2nd Stage Turbines on Arriel 1B, 1D, and 1D1 
Engines

    (i) Initially replace the 2nd stage turbine with a new or 
overhauled 2nd stage turbine as follows:
    (1) On or before August 31, 2006, replace the 2nd stage turbine 
with a new or overhauled 2nd stage turbine:
    (i) As soon as practicable after accumulating 1,500 hours TSN or 
TSO for Arriel 1D and 1D1 engines.
    (ii) As soon as practicable after accumulating 2,200 hours TSN 
or TSO for Arriel 1B engines.
    (2) After August 31, 2006, replace the 2nd stage turbine with a 
new or overhauled 2nd stage turbine:
    (i) Before accumulating 1,500 hours TSN or TSO for Arriel 1D and 
1D1 engines.
    (ii) Before accumulating 2,200 hours TSN or TSO for Arriel 1B 
engines.

Repetitive Replacements of 2nd Stage Turbines on Arriel 1B, 1D, and 1D1 
Engines

    (j) Thereafter, replace the 2nd stage turbine with a new or 
overhauled 2nd stage turbine within every 1,500 hours TSN or TSO for 
Arriel 1D and 1D1 engines, and within every 2,200 hours TSN or TSO 
for Arriel 1B engines.

[[Page 19666]]

Criteria for Overhauled 2nd Stage Turbines

    (k) Do the following to overhauled 2nd stage turbines, 
referenced in paragraphs (i) and (j) of this AD:
    (1) You must install new blades in the 2nd stage turbines of 
overhauled Arriel 1D and 1D1 engines.
    (2) You may install either overhauled or new blades in the 2nd 
stage turbines of overhauled Arriel 1B engines.

Relative Position Check Continuing Compliance Requirements

    (l) All 2nd stage turbines, including those that are new or 
overhauled, must continue to comply with relative position check 
requirements of paragraphs (f) and (j) of this AD.

Alternative Methods of Compliance

    (m) The Manager, Engine Certification Office, has the authority 
to approve alternative methods of compliance for this AD if 
requested using the procedures found in 14 CFR 39.19.

Related Information

    (n) DGAC airworthiness directive F-2004-047 R1, dated October 
26, 2005, also addresses the subject of this AD.

Material Incorporated by Reference

    (o) You must use the service information specified in Table 2 of 
this AD to perform the actions required by this AD. The Director of 
the Federal Register previously approved the incorporation by 
reference of the documents listed in Table 2 of this AD in 
accordance with 5 U.S.C. 552(a) and 1 CFR part 51, as of February 
28, 2006 (71 FR 3754, January 24, 2006). Contact Turbomeca, 40220 
Tarnos, France; telephone +33 05 59 74 40 00, fax +33 05 59 74 45 
15, for a copy of this service information. You may review copies at 
the Docket Management Facility; U.S. Department of Transportation, 
400 Seventh Street, SW., Nassif Building, Room PL-401, Washington, 
DC 20590-0001, on the Internet at http://dms.dot.gov, 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.

                                      Table 2.--Incorporation by Reference
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 Turbomeca mandatory alert service
           bulletin No.                      Page                 Update No.                    Date
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A292 72 0807, Total Pages: 17.....  ALL...................  Original.............  March 24, 2004.
A292 72 0809, Total Pages: 18.....  ALL...................  1....................  October 4, 2005.
A292 72 0810, Total Pages: 14.....  ALL...................  Original.............  March 24, 2004.
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    Issued in Burlington, Massachusetts, on April 11, 2006.
Francis A. Favara,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. E6-5646 Filed 4-14-06; 8:45 am]
BILLING CODE 4910-13-P