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PROPOSED AD PRATT & WHITNEY CANADA CORP. (FORMERLY PRATT & WHITNEY CANADA, INC.): Docket No. FAA-2010-0829; Directorate Identifier 2010-NE-23-AD.
COMMENTS DUE DATE

(a) We must receive comments by October 4, 2010.

AFFECTED AIRWORTHINESS DIRECTIVES (ADS)

(b) None.

APPLICABILITY

(c) This  AD applies  to Pratt  & Whitney  Canada Corp.  (P&WC) PW305A and
    PW305B turboprop engines with  certain impellers, part numbers  (P/Ns)
    30B2185, 30B2486, 30B2858-01,  or 30B4565-01 installed.  These engines
    are installed on, but not limited to, Hawker-Beech Corporation BAe.125
    series  1000A,  1000B,  and Hawker  1000  airplanes  and Learjet  Inc.
    Learjet 60 airplanes.

REASON

(d) This AD results from:

As a result of  a change in the  low-cycle fatigue lifing methodology  for
the IMI 834 material, the  recommended service life of certain  PW305A and
PW305B  Impellers  has been  reduced,  as published  in  the Airworthiness
Limitations (AWL) section of Engine Maintenance Manual (EMM).

The in-service life of impellers  P/N 30B2185, 30B2486 and 30B2858-01  has
been reduced from 12,000 to 7,000 cycles; and of P/N 30B4565-01 from 8,500
to 7,000 cycles.

We are issuing  this AD to  prevent failure of  the impeller, which  could
result in an uncontained event and possible damage to the airplane.

ACTIONS AND COMPLIANCE

(e) Unless already done, do the following actions.

(f) Within 30 days from the effective date of this AD, update AWL  section
    of your PW305 EMM P/N 30B1402, to incorporate Temporary Revision  (TR)
    AL-8,  dated January  20, 2010,  for  compliance  with the  revised in
    -service limits for  the affected Impellers,  installed on PW305A  and
    PW305B engine.

FAA AD DIFFERENCES

(g) None.

OTHER FAA AD PROVISIONS

(h) The following provisions also apply to this AD:

(i) Alternative Methods of Compliance (AMOCs): The Manager, Engine Certif-
    ication Office, FAA, has the  authority to approve AMOCs for  this AD,
    if requested using the procedures found in 14 CFR 39.19.

RELATED INFORMATION

(j) Refer  to MCAI  Transport Canada  Airworthiness Directive  CF-2010-09,
    dated March  17, 2010,  and P&WC  Temporary Revision  No. AL-8,  dated
    January 20,  2010, to  P&WC EMM  P/N 30B1402  for related information.
    Contact Pratt & Whitney Canada Corp., 1000 Marie-Victorin,  Longueuil,
    Quebec, Canada, J4G 1A1; telephone (800) 268-8000; fax (450) 647-2888;
    or go to: http://www.pwc.ca, for a copy of this service information.

(k) Contact James Lawrence, Aerospace Engineer, Engine  Certification Off-
    ice, FAA,  Engine &  Propeller Directorate,  12 New  England Executive
    Park,  Burlington,  MA 01803;  e-mail:  james.lawrence@faa.gov; phone:
    (781) 238-7176; fax: (781)  238-7199, for more information  about this
    AD.

Issued  in  Burlington,  Massachusetts, on  August  13,  2010. Francis  A.
Favara, Manager, Engine and Propeller Directorate, Aircraft  Certification
Service.

DATES: We must receive comments on this proposed AD by October 4, 2010.
PREAMBLE 
DEPARTMENT OF TRANSPORTATION

FEDERAL AVIATION ADMINISTRATION

14 CFR Part 39

[Docket No. FAA-2010-0829; Directorate Identifier 2010-NE-23-AD] RIN  2120
-AA64

AIRWORTHINESS DIRECTIVES; Pratt &  Whitney Canada Corp. (P&WC)  PW305A and
PW305B Turboprop Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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

SUMMARY: We propose  to adopt a  new airworthiness directive  (AD) for the
products listed above. This proposed AD results from mandatory  continuing
airworthiness  information  (MCAI)  issued  by  an  aviation  authority of
another country to identify and correct an unsafe condition on an aviation
product. The  MCAI describes  the unsafe  condition as:  As a  result of a
change  in  the  low-cycle  fatigue lifing  methodology  for  the  IMI 834
material,  the  recommended  service life  of  certain  PW305A and  PW305B
Impellers has been reduced, as published in the Airworthiness  Limitations
(AWL) section of Engine Maintenance  Manual (EMM). The in-service life  of
impellers P/N 30B2185, 30B2486 and 30B2858-01 has been reduced from 12,000
to 7,000 cycles; and of P/N 30B4565-01 from 8,500 to 7,000 cycles. We  are
proposing this AD to prevent  failure of the impeller, which  could result
in an uncontained event and possible damage to the airplane.

DATES: We must receive comments on this proposed AD by October 4, 2010.

ADDRESSES: You may send comments by any of the following methods:

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  Pratt &  Whitney  Canada  Corp., 1000  Marie-Victorin, Longueuil,
Quebec, Canada,  J4G 1A1;  telephone 800-268-8000;  fax 450-647-2888;  Web
site: www.pwc.ca, for the service information identified in this  proposed
AD.

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 proposed AD, the regulatory evaluation, any  comments
received,  and  other  information.  The  street  address  for  the Docket
Operations office (phone (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.

FOR FURTHER INFORMATION CONTACT: James Lawrence, Aerospace  Engineer, Eng-
ine Certification Office, FAA, Engine & Propeller Directorate, 12 New Eng-
land Executive Park, Burlington, MA 01803; e-mail: james.lawrence@faa.gov;
phone: (781) 238-7176; 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-2010-0829;   Directorate
Identifier  2010-NE-23-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).

DISCUSSION

Transport Canada, which is the  aviation authority for Canada, has  issued
Canada Airworthiness Directive CF-2010-09, dated March 17, 2010, (referred
to after  this as  "the MCAI"),  to correct  an unsafe  condition for  the
specified products. The MCAI states:

As a result of  a change in the  low-cycle fatigue lifing methodology  for
the IMI 834 material, the  recommended service life of certain  PW305A and
PW305B  Impellers  has been  reduced,  as published  in  the Airworthiness
Limitations (AWL) section of Engine Maintenance Manual (EMM).

The in-service life of impellers  P/N 30B2185, 30B2486 and 30B2858-01  has
been reduced from 12,000 to 7,000 cycles; and of P/N 30B4565-01 from 8,500
to 7,000 cycles.

This Airworthiness Directive (AD)  is issued to mandate  the incorporation
of the revised in-service life  limits for the affected impellers,  in the
AWL section of EMM, as introduced by Temporary Revision (TR) AL-8.

Within 30 days from the effective  date of this AD, update AWL  section of
your PW305 EMM P/N 30B1402, to incorporate TR AL-8 for compliance with the
revised in-service limits for the affected Impellers, installed on  PW305A
and PW305B engine.

You may obtain further information by examining the MCAI in the AD docket.

RELEVANT SERVICE INFORMATION

Pratt & Whitney Canada has  issued Maintenance Manual Part Number  30B1402
Temporary Revision  No. AL-8,  dated January  20, 2010.  The reduced cycle
limits described in this service  information are intended to correct  the
unsafe condition identified in the MCAI.

FAA'S DETERMINATION AND REQUIREMENTS OF THIS PROPOSED AD

This product has been approved by the aviation authority of Canada, and is
approved for  operation in  the United  States. Pursuant  to our bilateral
agreement  with Canada,  they have  notified us  of the  unsafe  condition
described in  the MCAI  and service  information referenced  above. We are
proposing this AD because we evaluated all information provided by  Canada
and  determined the  unsafe condition  exists and  is likely  to exist  or
develop on other products of the same type design.

COSTS OF COMPLIANCE

Based on the service information, we estimate that this proposed AD  would
affect about 114 products of U.S. registry. We also estimate that it would
take about 0 work-hours per product  to comply with this proposed AD.  The
average labor rate is $85  per work-hour. Required parts would  cost about
$54,288 per product. Based on these  figures, we estimate the cost of  the
proposed  AD on  U.S. operators  to be  $6,188,832. Our  cost estimate  is
exclusive of possible warranty coverage.

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.

REGULATORY FINDINGS

We 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  responsib-
ilities among the various levels of government.

For the reasons discussed above, I certify 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 Pro-
   cedures (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 a regulatory evaluation of the estimated costs to comply  with
this proposed 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.

THE PROPOSED AMENDMENT

Accordingly, under the authority delegated to me by the Administrator, the
FAA 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 adding the following new AD: