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ADs updated daily at www.Tdata.com
PROPOSED AD 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 April 9, 2010.

AFFECTED ADS

(b) This AD supersedes AD 2008-07-01, Amendment 39-15442.

APPLICABILITY

(c) This  AD applies  to Turbomeca  Arriel 1B  (that incorporate Turbomeca
    Modification (mod) TU  148), Arriel 1D,  1D1, and 1S1  engines that do
    not incorporate mod  TU 347. Arriel  1B engines are  installed on, but
    not   limited   to,  Eurocopter   AS-350B   and  AS-350BA   "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 Corporation S-76C helicopters.

UNSAFE CONDITION

(d) This AD  results from reports  of new cases  of failures of  2nd stage
    turbine blades since we issued  AD 2008-07-01. We are issuing  this AD
    to prevent the failure of 2nd stage turbine blades, which could result
    in an uncommanded in-flight  engine shutdown, and a  subsequent forced
    autorotation landing or accident.

COMPLIANCE

(e) You are responsible for having the actions required by this AD perfor-
    med  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  Service Bulletins  (MSBs) 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
--------------------------------------------------------------------------
  TURBOMECA      INITIAL RELATIVE                     MANDATORY SERVICE
 ENGINE MODEL    POSITION CHECK      REPETITIVE           BULLETIN
                 INTERVAL             INTERVAL
--------------------------------------------------------------------------
Arriel 1B (that  Within 1,200 hrs  Within 150 hours   A292 72 0807, Ver-
incorporate mod  time-since-new    time-in-service-   sion E, dated Oct-
TU 148), 1D1,    (TSN) or time-    since-last-relat-  ober 29, 2009, para-
and 1D.          since-overhaul    ive-position-      graphs 2B(1)(a) and
                 (TSO) or 3,500    check TSLRPC).     (b), or 2B(2)(a).
                 cycles-since-new
                 (CSN) or cycles-
                 since-overhaul
                 (CSO), whichever
                 occurs earlier.
Arriel 1S1.....  Within 1,200 hrs  Within 150 hours   A292 72 0810, Ver-
                 TSN or TSO or     TSLRPC             sion C, dated July
                 3,500 CSN or CSO,                    24, 2009, para-
                 whichever occurs                     graphs 2B(1)(a) and
                 earlier.                             (b), or 2B(2)(a),
                                                      (b), and (c).
--------------------------------------------------------------------------

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  Turbomeca
    MSBs indicated.

CREDIT FOR PREVIOUS RELATIVE POSITION CHECKS

(h) Credit is allowed for  previous relative position checks of  2nd stage
    turbine blades done using the following Turbomeca MSBs:

(1) MSB No. A292 72 0263, Update Nos. 1 through 5.

(2) MSB No. A292 72 0807, Original, and Update No. 1 through Version D.

(3) MSB No. A292 72 0809, Update No. 1.

(4) MSB No. A292 72 0810, Original, and Version A through Version B.

INITIAL REPLACEMENT OF 2ND STAGE TURBINES ON ARRIEL 1B ENGINES

(i) Initially replace the Arriel 1B 2nd stage turbine disk and blades with
    an inspected 2nd  stage turbine that  does not incorporate  mod TU 347
    and  is  fitted with  new  blades or  with  a 2nd  stage  turbine that
    incorporates mod TU 347, using Turbomeca MSB No. A292 72 0807, Version
    E, dated October 29, 2009, paragraphs 2B(1)(c) or (d), or 2B(2)(b)  or
    (c), at the following times:

(1) Replace before further flight on engines with a 2nd stage turbine disk
    having accumulated more than  2,200 hours TIS since-new  or since-last
    -inspection, whichever occurs later, or with 2nd stage turbine  blades
    that have accumulated more than 3,000 hours TIS since-new.

(2) For engines  with 2nd stage  turbine blades having  accumulated on the
    effective date of  this AD, more  than 1,800 hours  TIS since-new, but
    3,000 or fewer hours TIS since-new, replace before reaching any of the
    following:

(i) 400 hours TIS from the effective date of this AD, or

(ii) 3,000 hours TIS since-new on the 2nd stage turbine blades,

or

(iii) 2,200 hours TIS since-new or since-last-inspection, whichever occurs
      later, on the 2nd stage turbine disk.

(3) For engines  with 2nd stage  turbine blades having  accumulated on the
    effective date  of this  AD, more  than 900  hours TIS  since-new, but
    1,800 or fewer hours TIS since-new, replace before reaching any of the
    following:

(i) 800 hours TIS from the effective date of this AD, or

(ii) 2,200 hours TIS since-new or since-last-inspection, whichever  occurs
     later, on the 2nd stage turbine disk.

(4) For engines  with 2nd stage  turbine blades having  accumulated on the
    effective date of this AD,  900 or fewer hours TIS  since-new, replace
    before the 2nd stage turbine  blades have accumulated 1,200 hours  TIS
    since-new.

REPETITIVE REPLACEMENTS OF 2ND STAGE TURBINES ON ARRIEL 1B ENGINES

(j) Thereafter, for 2nd stage turbines that do not incorporate mod TU 347,
    replace the 2nd stage turbine  disk and blades before the  blades have
    accumulated 1,200 hours TIS since-new.

INITIAL REPLACEMENT OF 2ND STAGE TURBINES ON ARRIEL 1D AND 1D1 ENGINES

(k) Initially replace  the Arriel 1D  and 1D1 2nd  stage turbine disk  and
    blades with an inspected turbine that does not incorporate mod TU  347
    and is fitted with new blades or with a turbine that incorporates  mod
    TU 347, using Turbomeca MSB No. A292 72 0807, Version E, dated October
    29,  2009, paragraphs  2B(1)(c) or  (d), or  2B(2)(b) or  (c), at  the
    following times:

(1) Replace before further flight on engines with a 2nd stage turbine disk
    having accumulated more than  1,500 hours TIS since-new  or since-last
    -inspection, whichever occurs later, or with 2nd stage turbine  blades
    having accumulated more than 1,500 hours TIS since-new.

(2) For engines  with 2nd stage  turbine blades having  accumulated on the
    effective date  of this  AD, more  than 900  hours TIS  since-new, but
    1,500  or fewer  hours TIS  since-new, replace  before the  2nd  stage
    turbine blades have accumulated  1,500 hours TIS since-new,  or before
    the 2nd stage turbine disk has accumulated 1,500 hours TIS since- new,
    whichever occurs first.

(3) For engines  with 2nd stage  turbine blades having  accumulated on the
    effective date of this AD,  900 or fewer hours TIS  since-new, replace
    before the 2nd stage turbine  blades have accumulated 1,200 hours  TIS
    since-new.

REPETITIVE REPLACEMENTS OF 2ND STAGE TURBINES ON ARRIEL 1D AND 1D1 ENGINES

(l) Thereafter, for 2nd stage turbines that do not incorporate mod TU 347,
    replace the 2nd stage turbine  disk and blades before the  blades have
    accumulated 1,200 hours TIS since-new.

RELATIVE POSITION CHECK CONTINUING COMPLIANCE REQUIREMENTS

(m) All 2nd  stage turbines, including  those that are  new or overhauled,
    must continue to comply with  the actions specified in paragraphs  (f)
    and (g) of this AD, unless mod TU 347 has been incorporated.

OPTIONAL TERMINATING ACTION

(n) Installing a new turbine, P/N 0 292 25 039 0, (incorporation of mod TU
    347) terminates  the requirements  to perform  the repetitive  actions
    specified in paragraphs (g), (j), and (l) of this AD.

ALTERNATIVE METHODS OF COMPLIANCE

(o) 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

(p) The EASA  airworthiness directive 2009-0236,  dated October 29,  2009,
    also addresses the subject of this AD.

(q) Contact Kevin Dickert, Aerospace  Engineer, Engine  Certification Off-
    ice, FAA, Engine and  Propeller Directorate, 12 New  England Executive
    Park, Burlington, MA  01803; e-mail: kevin.dickert@faa.gov;  telephone
    (781) 238-7117, fax  (781) 238-7199, for  more information about  this
    AD.

Issued in Burlington, Massachusetts, on March 1, 2010. Thomas A. Boudreau,
Acting Manager, Engine  and Propeller Directorate,  Aircraft Certification
Service.

DATES: We must receive any comments on this proposed AD by April 9, 2010.
PREAMBLE  
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), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

--------------------------------------------------------------------------

SUMMARY: The FAA proposes to supersede an existing airworthiness directive
(AD) for certain Turbomeca Arriel 1B, 1D, 1D1, and 1S1 turboshaft engines.
That AD requires  initial and repetitive  relative position checks  of the
gas  generator  2nd stage  turbine  blades on  Turbomeca  Arriel 1B  (that
incorporate Turbomeca Modification (mod) TU 148), Arriel 1D, 1D1, and  1S1
turboshaft  engines that  do not  incorporate  mod  TU 347.  That AD  also
requires  initial and  repetitive replacements  of 2nd  stage turbines  on
Arriel 1B, 1D,  and 1D1 engines.  This proposed AD  would require lowering
the  repetitive  threshold  for  relative  position  checks  on  Arriel 1B
engines. This  proposed AD  would also  require lowering  the initial  and
repetitive thresholds for replacement of 2nd stage turbines on Arriel  1B,
1D, and 1D1 engines. This proposed AD results from reports of new cases of
failures of 2nd stage turbine blades since we issued AD 2008-07-01. We are
proposing this  AD to  prevent the  failure of  2nd stage  turbine blades,
which could  result in  an uncommanded  in-flight engine  shutdown, and  a
subsequent forced autorotation landing or accident.

DATES: We must receive any comments on this proposed AD by April 9, 2010.

ADDRESSES: Use one of the following addresses to comment on this  proposed
AD.

Federal eRulemaking Portal: Go  to  http://www.regulations.gov  and follow
the instructions for sending your comments electronically.

Mail: Docket Management Facility, U.S. Department of Transportation,  1200
New  Jersey  Avenue,  SE.,  West  Building  Ground  Floor,  Room  W12-140,
Washington, DC 20590-0001.

Hand Delivery: Deliver to  Mail address above between  9 a.m. and 5  p.m.,
Monday through Friday, except Federal holidays.

Fax: (202) 493-2251.

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.

FOR FURTHER INFORMATION CONTACT: Kevin Dickert, Aerospace Engineer, Engine
Certification  Office,  FAA,  Engine  and  Propeller  Directorate,  12 New
England    Executive     Park,    Burlington,     MA    01803;     e-mail:
kevin.dickert@faa.gov; telephone (781) 238-7117, fax (781) 238-7199.

SUPPLEMENTARY INFORMATION:

COMMENTS INVITED

We invite you to send any written relevant data, views, or arguments about
this  proposed AD.  Send your  comments to  an address  listed  under  the
ADDRESSES  section.  Include   "Docket  No.  FAA-2005-21242;   Directorate
Identifier  2005-NE-09-AD"   at  the   beginning  of   your  comments.  We
specifically  invite  comments   on  the  overall   regulatory,  economic,
environmental, and energy  aspects of this  proposed AD. We  will consider
all comments received by the closing  date and may amend this proposed  AD
based on 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  with
FAA personnel concerning  this proposed AD.  Using the search  function of
the Web site, anyone can find and read the comments in any of our dockets,
including, if provided,  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).

EXAMINING THE AD 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 regulatory evaluation, any comments received,
and other information. The street address for the Docket Operations office
(telephone (800) 647-5527) is the same as the Mail address provided in the
ADDRESSES section.  Comments will  be available  in the  AD docket shortly
after receipt.

DISCUSSION

On March 17, 2008, the FAA issued AD 2008-07-01, Amendment 39-15442 (73 FR
15866, March 26, 2008). That  AD requires initial and repetitive  relative
position checks of the gas generator 2nd stage turbine blades on Turbomeca
Arriel  1B (that  incorporate mod  TU 148),  1D, 1D1,  and 1S1  turboshaft
engines that do not incorporate mod TU 347. That AD also requires  initial
and  repetitive replacements  of 2nd  stage turbines  on 1B,  1D, and  1D1
engines.  The  European  Aviation  Safety  Agency  (EASA),  which  is  the
Technical Agent for the Member States of the European Community,  recently
notified us that an unsafe condition likely exists on Turbomeca Arriel 1B,
1D, 1D1, and 1S1 turboshaft engines.

SINCE AD 2008-07-01 WAS ISSUED

Since AD 2008-07-01 was issued, EASA  reports that in engines that do  not
incorporate mod TU 347, new cases of gas generator 2nd stage turbine blade
release  have  occurred,  at lower  blade  service  lives than  previously
reported. EASA issued  AD 2009-0236, dated  October 29, 2009,  to optimize
the 2nd stage turbine blade life limit and the replacement allowances  for
turbines currently in service in Europe, based on parts availability while
keeping the risk level within acceptable limits.

RELEVANT SERVICE INFORMATION

We  have  reviewed  and  approved  the  technical  contents  of  Turbomeca
Mandatory  Service  Bulletin (MSB)  No.  A292 72  0807,  Version E,  dated
October  29, 2009,  that describes  procedures for  the relative  position
check of 2nd stage turbine  blades, and replacement of 2nd  stage turbines
that do not incorporate mod TU 347, with inspected 2nd stage turbines,  or
with 2nd stage turbines that incorporate mod TU 347, on Arriel 1B, 1D, and
1D1 engines. We have also reviewed and approved the technical contents  of
Turbomeca MSB  No. A292  72 0810,  Version C,  dated July  24, 2009,  that
describes procedures for the relative position check of 2nd stage  turbine
blades on Arriel 1S1 engines. EASA classified these MSBs as mandatory  and
issued AD 2009-0236, dated October  29, 2009, to ensure the  airworthiness
of these Turbomeca Arriel engines in Europe.

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.  Under  this  bilateral airworthiness
agreement, EASA kept us informed of the situation described above. We have
examined the findings of the EASA, 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

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  supersedure, which  would
require lowering the repetitive threshold for relative position checks  on
Arriel  1B  engines. This  proposed  AD would  also  require lowering  the
initial and repetitive thresholds for replacement of 2nd stage turbines on
Arriel 1B, 1D, and 1D1 engines. The proposed AD would require that you  do
these actions using the service information described previously.

COSTS OF COMPLIANCE

Based on the service information, we estimate that this proposed AD  would
affect about 587 Turbomeca Arriel 1B, 1D, 1D1, and 1S1 turboshaft  engines
installed on  products of  U.S. registry.  We also  estimate that it would
take about 2 work-hours per engine to perform one inspection, and about 40
work-hours per  engine to  replace the  gas turbine  discs and blades. The
average labor rate is $85  per work-hour. Required parts would  cost about
$54,000 per engine. Based  on these figures, we  estimate the cost of  the
proposed AD on U.S. operators to be $33,793,590.

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 devel-
op on products identified in this rulemaking action.

REGULATORY FINDINGS

We  have  determined  that  this proposed  AD  would  not  have federalism
implications under Executive Order 13132. This proposed AD 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 AD:

1. Is not a "significant regulatory action" under Executive Order 12866;

2. Is not a "significant rule" under the DOT Regulatory Policies and Proc-
   edures (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. 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, Incorporation by reference,
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 39-15442 (73 FR 15866,
   March 26, 2008) and by adding a new airworthiness directive, to read as
   follows: