[Federal Register Volume 68, Number 109 (Friday, June 6, 2003)]
[Proposed Rules]
[Pages 33885-33887]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-14276]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2003-NE-11-AD]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney Canada Models PW118, 
PW120, PW120A, and PW121 Turboprop Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for Pratt & Whitney Canada (PWC) models PW118, PW120, PW120A, and PW121 
turboprop engines. This proposed AD would require replacing the low 
pressure rotor speed (NL) sensor port sealing tube and reworking or 
replacing the external air tube connecting the P2.5/P3 switching valve 
to the rear inlet case. This proposed AD is prompted by a report of an 
internal oil fire in the engine intercompressor case (ICC). A fire in 
the ICC could cause the existing tubes to disengage due to melted 
brazing on the tubes. Once these tubes disengage, the ICC fire then 
develops into an external fire within the engine nacelle cavity. The 
actions specified in this proposed AD are intended to prevent fire in 
the engine nacelle cavity, in-flight engine shutdown, and airplane 
damage.

DATES: We must receive any comments on this proposed AD by August 5, 
2003.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD:
    [sbull] By mail: Federal Aviation Administration (FAA), New England 
Region, Office of the Regional Counsel, Attention: Rules Docket No. 
2003-NE-11-AD, 12 New England Executive Park, Burlington, MA 01803-
5299.
    [sbull] By fax: (781) 238-7055.
    [sbull] By e-mail: [email protected]
    You may get the service information identified in this proposed AD 
from Pratt & Whitney Canada, Technical Publications Department, 1000 
Marie Victorin, Longueuil, Quebec J4G 1A1.
    You may examine the AD docket at the FAA, New England Region, 
Office of the Regional Counsel, 12 New England Executive Park, 
Burlington, MA.

FOR FURTHER INFORMATION CONTACT: Ian Dargin, Aerospace Engineer, Engine 
Certification Office, FAA, Engine and Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803-5299; telephone (781) 238-
7178; fax (781) 238-7199.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to submit any written relevant data, views, or 
arguments regarding this proposal. Send your comments to an address 
listed under ADDRESSES. Include ``AD Docket No. 2003-NE-11-AD'' in the 
subject line of your comments.If you want us to acknowledge receipt of 
your mailed comments, send us a self-addressed, stamped postcard with 
the docket number written on it; we will date-stamp your postcard and 
mail it back to you. We specifically invite comments on the overall 
regulatory, economic, environmental, and energy aspects of the proposed 
AD. If a person contacts us through a nonwritten communication, and 
that contact relates to a substantive part of this proposed AD, we will 
summarize the contact and place the summary in the docket. We will 
consider all comments received by the closing date and may amend the 
proposed AD in light of those comments.
    We are reviewing the writing style we currently use in regulatory 
documents. We are interested in your comments on whether the style of 
this document is clear, and your suggestions to improve the clarity of 
our communications that affect you. You may get more information about 
plain language at http://www.plainlanguage.gov.

Examining the AD Docket

    You may examine the AD Docket (including any comments and service 
information), by appointment, between 8 a.m. and 4:30 p.m., Monday 
through Friday, except Federal holidays. See ADDRESSES for the 
location.

Discussion

    Transport Canada, which is the airworthiness authority for Canada, 
recently notified the FAA that an unsafe condition may exist on PWC 
models PW118, PW120, PW120A, and PW121 turboprop engines. Transport 
Canada advises that they have received a report of an internal oil fire 
in the engine ICC. An ICC fire melts the brazing on the external air 
tube connected to the P2.5/P3 switching valve, and on the low pressure 
rotor speed (NL) sensor port sealing tube, allowing both to disengage. 
Once these tubes disengage, the ICC fire then develops into an external 
fire within the engine nacelle cavity, resulting in in-flight engine 
shutdown and potential airplane damage.

Relevant Service Information

    We have reviewed and approved the technical contents of PWC Service 
Bulletin (SB) No. 20914, Revision 4, dated December 14, 2001. That SB 
describes procedures for replacing the low pressure rotor speed (NL) 
sensor port sealing tube and reworking or replacing the external air 
tube connecting the P2.5/P3 switching valve to the rear inlet case. 
Transport Canada classified this SB as mandatory and issued 
airworthiness directive No. CF-2002-10, dated January 28, 2002, in 
order to ensure the airworthiness of these PWC models PW118, PW120, 
PW120A, and PW121 turboprop engines in Canada.

FAA's Determination and Requirements of the Proposed AD

    These PWC models PW118, PW120, PW120A, and PW121 turboprop

[[Page 33886]]

engines, manufactured in Canada, are type-certificated for operation in 
the United States under the provisions of Sec.  21.29 of the Federal 
Aviation Regulations (14 CFR 21.29) and the applicable bilateral 
airworthiness agreement. Pursuant to this bilateral airworthiness 
agreement, Transport Canada has kept us informed of the situation 
described above. We have examined Transport Canada's findings, 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. Therefore, we are proposing this AD, which would 
require replacing the low pressure rotor speed (NL) sensor port sealing 
tube and reworking or replacing the external air tube connecting the 
P2.5/P3 switching valve to the rear inlet case. The proposed AD would 
require that these actions be done using the service information 
described previously.

Changes to 14 CFR Part 39--Effect on the Proposed AD

    On July 10, 2002, we published a new version of 14 CFR part 39 (67 
FR 47997, July 22, 2002), which governs the FAA's AD system. This 
regulation now includes material that relates to altered products, 
special flight permits, and alternative methods of compliance. This 
material previously was included in each individual AD. Since this 
material is included in 14 CFR part 39, we will not include it in 
future AD actions.

Costs of Compliance

    There are approximately 1,933 PWC models PW118, PW120, PW120A, and 
PW121 turboprop engines of the affected design in the worldwide fleet. 
We estimate that 1,160 engines installed on airplanes of U.S. registry 
would be affected by this proposed AD. We also estimate that it would 
take approximately 2 work hours per installed engine to replace the 
parts, and that the average labor rate is $60 per work hour. Required 
parts would cost approximately $1,966 per engine. Based on these 
figures, the total replacement cost of the proposed AD to U.S. 
operators is estimated to be $2,419,760. We also estimate that it would 
take approximately 2 work hours per tube to perform the rework in lieu 
of tube replacement, and required parts for rework would cost 
approximately $197 per engine. Based on these figures, the total rework 
cost of the proposed AD to U.S. operators is estimated to be $367,720. 
PWC has informed the FAA that it may provide the parts and labor to the 
operators at no cost, thereby substantially reducing the cost of the 
proposed rule.

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 
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 summary of the costs to comply with this proposal and 
placed it in the AD Docket. You may get a copy of this summary by 
sending a request to us at the address listed under ADDRESSES. Include 
``AD Docket No. 2003-NE-11-AD'' in your request.

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 adding the following new 
airworthiness directive:
Pratt & Whitney Canada: Docket No. 2003-NE-11-AD.

Comments Due Date

    (a) The FAA must receive comments on this airworthiness 
directive (AD) action by August 5, 2003.

Affected ADs

    (b) None.

Applicability

    (c) This AD is applicable to Pratt & Whitney Canada (PWC) models 
PW118, PW120, PW120A, and PW121 turboprop engines. These engines are 
installed on, but not limited to, Empresa Brasileira de Aeronautica 
(EMBRAER) EMB-120RT, 120ER, and 120FC, Bombardier Inc. (formerly 
Dehavilland of Canada) DHC-8-100 series, and Aerospatiale ATR 42-
200, -300, and -320 airplanes.

Unsafe Condition

    (d) This AD was prompted by a report of an internal oil fire in 
the engine intercompressor case (ICC). A fire in the ICC could cause 
the low pressure rotor speed (NL) sensor port sealing tube and the 
external air tube connecting the P2.5/P3 switching valve to the rear 
inlet case, to disengage due to melted brazing on the tubes. Once 
these tubes disengage, the ICC fire then develops into an external 
fire within the engine nacelle cavity. The actions specified in this 
AD are intended to prevent fire in the engine nacelle cavities, in-
flight engine shutdown, and airplane damage.

Compliance

    (e) Compliance with this AD is required at the next engine shop 
visit, or within 90 days after the effective date of this AD, 
whichever occurs first, unless already done.

Low Pressure Rotor Speed (NL) Sensor Port Sealing Tube

    (f) Replace the low pressure rotor speed (NL) sensor port 
sealing tube with an improved durability tube, in accordance with 
paragraphs 2.A. and 2.B., Accomplishment Instructions of PWC Service 
Bulletin (SB) No. 20914, Revision 4, dated December 14, 2001.

Switching Valve-to-Rear Inlet Case Sealing Air Tube Assembly

    (g) Remove the switching valve-to-rear inlet case sealing air 
tube assembly, in accordance with paragraph 2.C., Accomplishment 
Instructions of PWC SB No. 20914, Revision 4, dated December 14, 
2001, and do the following:
    (1) Either install an improved durability switching valve-to-
rear inlet case sealing air tube assembly, in accordance with 
paragraph 2.G., Accomplishment Instructions of PWC SB No. 20914, 
Revision 4, dated December 14, 2001; or
    (2) Rework the switching valve-to-rear inlet case sealing air 
tube assembly and install tube assembly, in accordance with 
paragraphs 2.D., 2.F., and 2.G., Accomplishment Instructions of PWC 
SB No. 20914, Revision 4, dated December 14, 2001.

Alternative Methods of Compliance

    (h) Alternative methods of compliance must be requested in 
accordance with 14 CFR part 39.19, and must be approved by the 
Manager, Engine Certification Office, FAA.

Material Incorporated by Reference

    (i) The replacements and rework must be done in accordance with 
PWC SB No. 20914, Revision 4, dated December 14, 2001.

Related Information

    (j) The subject of this AD is addressed in Transport Canada 
airworthiness directive No. CF-2002-10, dated January 28, 2002.


[[Page 33887]]


    Issued in Burlington, Massachusetts, on May 30, 2003.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 03-14276 Filed 6-5-03; 8:45 am]
BILLING CODE 4910-13-P