
[Federal Register: June 25, 2008 (Volume 73, Number 123)]
[Rules and Regulations]               
[Page 35900-35902]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr25jn08-7]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-0664; Directorate Identifier 2008-NE-04-AD; 
Amendment 39-15579; AD 2008-13-16]
RIN 2120-AA64

 
Airworthiness Directives; Pratt & Whitney Canada Corp. (P&WC) 
Models PW305A and PW305B Turbofan Engines

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 the 
products listed above. This 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:

    There have been two incidents of fan blade dislodgements due to 
blade fracture on relatively hi-time PW305 engines (over 5000 Hrs). 
The blade dislodgement in both cases was contained. However, engine 
installations sustained considerable collateral damage. The root 
cause of fan blade fracture was determined to be the under-minimum 
material condition at the fracture location.

This AD requires actions that are intended to address the unsafe 
condition described in the MCAI, which could result in an engine 
shutdown and damage to the airplane.

DATES: This AD becomes effective July 10, 2008.
    The Director of the Federal Register approved the incorporation by 
reference of P&WC Alert Service Bulletin (ASB) PW300-72-A24588, 
Revision 2, dated November 27, 2007, listed in the AD as of July 10, 
2008.
    We must receive comments on this AD by July 25, 2008.

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: 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.

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.

FOR FURTHER INFORMATION CONTACT: Ian Dargin, Aerospace Engineer, Engine 
Certification Office, FAA, Engine & Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803; e-mail: 
ian.dargin@faa.gov; telephone (781) 238-7178; fax (781) 238-7199.

SUPPLEMENTARY INFORMATION:

Discussion

    Transport Canada (TC), which is the aviation authority for Canada, 
has issued Airworthiness Directive CF-2008-08R1, dated March 18, 2008, 
(referred to after this as ``the MCAI''), to correct an unsafe 
condition for the specified products. The MCAI states:

    There have been two incidents of fan blade dislodgements due to 
blade fracture on relatively hi-time PW305 engines (over 5000 Hrs). 
The blade dislodgement in both cases was contained. However, engine 
installations sustained considerable collateral damage. The root 
cause of fan blade fracture was determined to be the under-minimum 
material condition at the fracture location.

    P&WC has established that the subject under-minimum material 
condition is limited only to fan blades P/N 30B2855-01, manufactured 
under heat code: MCBWF. Accordingly, P&WC on 24 August 2007 issued 
Alert Service Bulletin (ASB) No. A24588, requiring, on priority 
bases, identification and removal of all such discrepant fan blades 
from service, in accordance with Special Instructions (SI) No. 37-
2007. ASB No. A24588 was subsequently revised (Rev. 2) on 27 
November 2007 to include clarification on the incorporation of 
another Service Bulletin (SB) No. 24595, on the same subject.

    Considering the potentially hazardous consequence of possible 
uncontained dislodgement of discrepant blade and its impact on 
aircraft safety, this AD is issued to mandate the inspection of the 
affected engine low-pressure (LP) compressor fan blades in 
accordance with ASB A24588 requirements.

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

Relevant Service Information

    P&WC has issued ASB PW300-72-A24588, Revision 2, dated November 27, 
2007. The actions described in this service information are intended to 
correct the unsafe condition identified in the MCAI.

FAA's Determination and Requirements of This 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 issuing this AD because we evaluated all the 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.

FAA's Determination of the Effective Date

    An unsafe condition exists that requires the immediate adoption of 
this AD. The FAA has found that the risk to the flying public justifies 
waiving notice and comment prior to adoption of this rule because fan 
blades identified by this AD have been found to have an under-minimum 
material thickness condition which has caused failure and release of 
fan blades. In one event, the fan blade failure (contained) resulted in 
high engine vibrations causing the loss of the upper and lower engine 
cowls. Fan blade failure could result in an engine shutdown and damage 
to the airplane. Therefore, we 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.

[[Page 35901]]

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. We invite you to send any written relevant data, views, or 
arguments about this AD. Send your comments to an address listed under 
the ADDRESSES section. Include ``Docket No. FAA-2008-0664; Directorate 
Identifier 2008-NE-04-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 products 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.
    For the reasons discussed above, 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 a regulatory 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:

2008-13-16 Pratt & Whitney Canada Corp. (P&WC) (Formerly Pratt & 
Whitney Canada, Inc.) : Amendment 39-15579.; Docket No. FAA-2008-
0664; Directorate Identifier 2008-NE-04-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective July 10, 
2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to P&WC models PW305A and PW305B turbofan 
engines that have a serial number (SN) listed in Table 1 of this AD. 
These engines are installed on, but not limited to, Bombardier 
Learjet M60 and Hawker Beechcraft 1000 series airplanes.

                    Table 1.--Affected Engines by SN
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CA0192
CA0195
CA0197
CA0199
CA0200
CA0202
CA0203
CA0204
CA0206
CA0207
CA0208
CA0209
CA0210
CA0211
CA0212
CA0213
CA0214
CA0215
CA0216
CA0217
CA0218
CA0220
CA0221
CA0223
CA0228
CA0231
CA0232
CA0234
CA0235
CA0240
CA0241
CA0243
CA0244
CA0246
CA0247
CA0257
CA0259
CA0260
CA0280
CA0300
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Reason

    (d) There have been two incidents of fan blade dislodgements due 
to blade fracture on relatively hi-time PW305 engines (over 5000 
Hrs). The blade dislodgement in both cases was contained. However, 
engine installations sustained considerable collateral damage. The 
root cause of fan blade fracture was determined to be the under-
minimum material condition at the fracture location.
    This AD requires actions that are intended to address the unsafe 
condition described in the MCAI, which could result in an engine 
shutdown and damage to the airplane.

Actions and Compliance

    (e) Unless already done, do the following actions on all 
affected engines as specified in the applicability section of this 
AD, accomplish in accordance with P&WC Alert Service Bulletin (ASB) 
PW300-72-A24588, Revision 2, dated November 27, 2007:
    (1) For engines with more than 5,000 hours of operating time, 
before next flight, inspect low-pressure (LP) compressor fan blades 
and replace any blade that is found to be under-minimum material 
condition.
    (2) For engines with 5,000 or less, but more than 4,000 hours of 
operating time, within 30 hours of operating time from the effective 
date of this AD, but not later than September 30, 2008, inspect LP 
compressor fan blades and replace any blade that is found to be 
under-minimum material condition.
    (3) For engines with 4,000 or less, but more than 2,500 hours of 
operating time, no later than September 30, 2008, inspect LP 
compressor fan blades and replace any blade that is found to be 
under-minimum material condition, in accordance with one of the 
following schedules, whichever occurs first:
    (i) At the next first stage high-pressure compressor rotor 
inspection (Ref 05-20-00 scheduled maintenance checks), or
    (ii) At the next scheduled opportunity where the LP compressor 
fan is removed (Ref. Hot Section Inspection or Overhaul Shop Visit), 
or
    (iii) Within 300 hours of operating time from August 24, 2007.

[[Page 35902]]

    (4) For engines with 2,500 or less hours of operating time, 
before it accumulates 4,000 hours of operating time, but not later 
than September 30, 2008, inspect LP compressor fan blades and 
replace any blade that is found to be under-minimum material 
condition.

Previous Credit

    (f) Inspection of the fan blades for an under-minimum material 
condition done before the effective date of this AD that used P&WC 
ASB PW300-72-A24588, dated August 24, 2007; or Revision 1, dated 
October 26, 2007; or P&WC SB PW300-72-24595, dated October 26, 2007; 
or Revision 1, dated November 28, 2007, comply with the requirements 
specified in this AD.

Other FAA AD Provisions

    (g) The following provisions also apply to this AD:
    (1) Alternative Methods of Compliance (AMOCs): The Manager, 
Engine Certification Office, FAA, has the authority to approve AMOCs 
for this AD, if requested using the procedures found in 14 CFR 
39.19.
    (2) Special Flight Permits: We are limiting Special Flight 
Permits to one repositioning maintenance flight to facilitate the 
subject inspection.

Related Information

    (h) Refer to Transport Canada Airworthiness Directive CF-2008-
08R1, dated March 18, 2008; P&WC ASB PW300-72-A24588, Revision 2, 
dated November 27, 2007; and P&WC SB PW300-72-24595, Revision 1, 
dated November 28, 2007, for related information.
    (i) Contact Ian Dargin, Aerospace Engineer, Engine Certification 
Office, FAA, Engine & Propeller Directorate, 12 New England 
Executive Park, Burlington, MA 01803; e-mail: ian.dargin@faa.gov; 
telephone (781) 238-7178; fax (781) 238-7199, for more information 
about this AD.

Material Incorporated by Reference

    (j) You must use Pratt & Whitney Canada Corp. Alert Service 
Bulletin PW300-72-A24588, Revision 2, dated November 27, 2007, to do 
the actions required by this AD, unless the AD specifies otherwise.
    (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 Pratt 
& Whitney Canada Corp., 1000 Marie-Victorin, Longueuil, Quebec, 
Canada J4G 1A1, telephone: (800) 268-8000.
    (3) You may review copies at the FAA, New England Region, 12 New 
England Executive Park, Burlington, MA; 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 Burlington, Massachusetts, on June 13, 2008.
Peter A. White,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. E8-13854 Filed 6-24-08; 8:45 am]

BILLING CODE 4910-13-P
