[Federal Register Volume 63, Number 193 (Tuesday, October 6, 1998)]
[Rules and Regulations]
[Pages 53560-53562]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-26528]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-ANE-58-AD; Amendment 39-10817; AD 98-17-10]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney Canada PW530A Series 
Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule, request for comments.

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SUMMARY: This document publishes in the Federal Register an amendment 
adopting Airworthiness Directive (AD) 98-17-10 that was sent previously 
to all known U.S. owners and operators of Pratt & Whitney Canada (PWC) 
PW530A series turbofan engines by individual letters. This AD requires 
recording engine surge events in the aircraft maintenance records. If 
an engine surge event is experienced, this AD requires, prior to the 
next flight, inspecting that engine for evidence of second stage stator 
vanes rubbing on the compressor rotor. In addition, this AD requires 
reworking all affected engines to increase the clearance between the 
second stage stator vanes and the compressor rotor. This amendment is 
prompted by reports of 4 inflight engine shutdowns and 2 additional 
unscheduled engine removals for significant compressor rotor damage. 
The actions specified by this AD are intended to prevent an inflight 
engine shutdown due to rubbing of the second stage stator vanes on the 
compressor rotor.

DATES: Effective October 21, 1998, to all persons except those persons 
to whom it was made immediately effective by priority letter AD 98-17-
10, issued on August 7, 1998, which contained the requirements of this 
amendment.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of October 21, 1998.
    Comments for inclusion in the Rules Docket must be received on or 
before December 7, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), New England Region, Office of the Regional 
Counsel, Attention: Rules Docket No. 98-ANE-58-AD, 12 New England 
Executive Park, Burlington, MA 01803-5299. Comments may also be sent 
via the Internet using the following address: ``9-ad-
[email protected]''. Comments sent via the Internet must contain 
the docket number in the subject line.
    The applicable service information may be obtained from Pratt & 
Whitney Canada, Inc., 1000 Marie-Victorin, Longueuil, Quebec, Canada 
J4G 1A1; Attn: Supervisor, Publications Customer Service (01CA4); 
telephone (514) 647-2705, fax (514) 647-2702. This information may be 
examined at the FAA, New England Region, Office of the Regional 
Counsel, 12 New England Executive Park, Burlington, MA; or at the 
Office of the Federal Register, 800 North Capitol Street, NW., suite 
700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Richard Woldan, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803-5299; telephone (781) 
238-7136, fax (781) 238-7199.

SUPPLEMENTARY INFORMATION: Transport Canada, which is the airworthiness 
authority for Canada, recently notified the Federal Aviation 
Administration (FAA) that an unsafe condition may exist on certain 
Pratt & Whitney Canada (PWC) PW530A series turbofan engines. Transport 
Canada advises that they have received reports of 4 inflight engine 
shutdowns and 2 additional unscheduled engine removals for significant 
compressor rotor damage. The investigation revealed that compressor 
rotor damage and a high rate of inflight engine shutdowns result from 
rubbing of the second stage stator vanes on the compressor rotor. The 
original type design second stage stator clearance was insufficient to 
prevent rubbing of the stator vanes on the compressor rotor during all 
phases of engine operation. This condition, if not corrected, can 
result in an inflight engine shutdown due to rubbing of the second 
stage stator vanes on the compressor rotor.
    PWC has issued Service Bulletin (SB) No. PW500-72-30063, Revision 
2, dated July 10, 1998, that specifies inspection procedures for 
rubbing of the second stage stator vanes on the compressor rotor, and 
SB No. PW500-72-30044, Revision 2, dated July 10, 1998, that specifies 
procedures for reworking the engine to increase the clearance between 
the second stage stator vanes and the compressor rotor. Transport 
Canada classified these SBs as mandatory and issued airworthiness 
directive (AD) CF-98-18, dated July 16, 1998, in order to assure the 
airworthiness of these engines in Canada.
    This engine model is manufactured in Canada 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. Pursuant to

[[Page 53561]]

this bilateral airworthiness agreement, Transport Canada has kept the 
FAA informed of the situation described above. The FAA has examined the 
findings of Transport Canada, 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.
    On August 7, 1998, the Federal Aviation Administration (FAA) issued 
priority letter airworthiness directive (AD) 98-17-10, applicable to 
PWC PW530A series turbofan engines.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other engines of this same type design, this AD 
requires, for aircraft with one or more affected engines identified by 
serial numbers (S/Ns) in the applicability section of this AD, 
recording engine surge events in the aircraft maintenance records. If 
an engine surge event is experienced, this AD requires, prior to the 
next flight, inspecting that engine for evidence of second stage stator 
vanes rubbing on the compressor rotor. If evidence of rubbing is 
discovered, this AD requires, prior to further flight, removal from 
service of the engine that experienced rubbing and replacement with a 
serviceable engine. In addition, this AD requires, within 200 hours 
time in service (TIS) after the effective date of this AD, or prior to 
December 31, 1998, whichever occurs first, reworking all affected 
engines to increase the clearance between the second stage stator vanes 
and the compressor rotor. The calendar end-date was determined based 
upon risk analysis. The actions are required to be accomplished in 
accordance with the SBs described previously.
    Since it was found that immediate corrective action was required, 
notice and opportunity for prior public comment thereon were 
impracticable and contrary to the public interest, and good cause 
existed to make the AD effective immediately by individual letters 
issued on August 7, 1998, to all known U.S. owners and operators of PWC 
PW530A series turbofan engines. These conditions still exist, and the 
AD is hereby published in the Federal Register as an amendment to 
Section 39.13 of part 39 of the Federal Aviation Regulations (14 CFR 
part 39) to make it effective to all persons.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this rule by 
submitting such written data, views, or arguments as they may desire. 
Communications should identify the Rules Docket number and be submitted 
in triplicate to the address specified under the caption ADDRESSES. All 
communications received on or before the closing date for comments will 
be considered, and this rule may be amended in light of the comments 
received. Factual information that supports the commenter's ideas and 
suggestions is extremely helpful in evaluating the effectiveness of the 
AD action and determining whether additional rulemaking action would be 
needed.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the rule. All comments submitted will be 
available, both before and after the closing date for comments, in the 
Rules Docket for examination by interested persons. A report that 
summarizes each FAA-public contact concerned with the substance of this 
AD will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 98-ANE-58-AD.'' The postcard will be date stamped and 
returned to the commenter.
    The regulations adopted herein will not have substantial direct 
effects 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. Therefore, in 
accordance with Executive Order 12612, it is determined that this final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and is not a ``significant regulatory action'' 
under Executive Order 12866. It has been determined further that this 
action involves an emergency regulation under DOT Regulatory Policies 
and Procedures (44 FR 11034, February 26, 1979). If it is determined 
that this emergency regulation otherwise would be significant under DOT 
Regulatory Policies and Procedures, a final regulatory evaluation will 
be prepared and placed in the Rules Docket. A copy of it, if filed, may 
be obtained from the Rules Docket at the location provided under the 
caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends part 39 of 
the Federal Aviation Regulations (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. Section 39.13 is amended by adding the following new 
airworthiness directive:

98-17-10 Pratt & Whitney Canada: Amendment 39-10817 Docket 98-ANE-
58-AD.

    Applicability: Pratt & Whitney Canada (PWC) PW530A series 
turbofan engines, with serial numbers (S/Ns) PCE-DA0001 through PCE-
DA0059, and S/Ns PCE-DA0061 through PCE-DA0064 (S/N PCE-DA0060 is 
not affected, as it was shipped with the increased type design 
clearance). These engines are installed on but not limited to Cessna 
Citation Model 550 Bravo aircraft.

    Note 1: This airworthiness directive (AD) applies to each engine 
identified in the preceding applicability provision, regardless of 
whether it has been modified, altered, or repaired in the area 
subject to the requirements of this AD. For engines that have been 
modified, altered, or repaired so that the performance of the 
requirements of this AD is affected, the owner/operator must request 
approval for an alternative method of compliance in accordance with 
paragraph (e) of this AD. The request should include an assessment 
of the effect of the modification, alteration, or repair on the 
unsafe condition addressed by this AD; and, if the unsafe condition 
has not been eliminated, the request should include specific 
proposed actions to address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent inflight engine shutdown due to rubbing of the second 
stage stator vanes on the compressor rotor, accomplish the 
following:
    (a) In the event of an engine surge, make a record of the engine 
which surged and the date and approximate time of the event in the 
aircraft maintenance records. For this purpose, an engine surge is 
defined as unstable engine operation which is accompanied by unusual 
sounds which could be described as bangs, pops, growls, or rumbles 
and which may also be accompanied by increased engine vibration 
levels.

[[Page 53562]]

    (b) If an engine surge event is experienced, prior to the next 
flight, inspect that engine for evidence of rubbing of the second 
stage stator vanes on the compressor rotor in accordance with PWC 
Service Bulletin (SB) No. PW500-72-30063, Revision 2, dated July 10, 
1998.
    (c) If evidence of rubbing is discovered, prior to further 
flight, remove from service the engine that experienced rubbing and 
replace with a serviceable engine.
    (d) Within 200 hours time in service (TIS) after the effective 
date of this AD, or prior to December 31, 1998, whichever occurs 
first, rework all affected engines identified by S/N in the 
applicability of this AD to increase the clearance between the 
second stage stator vanes and the compressor rotor, in accordance 
with PWC SB No. PW500-72-30044, Revision 2, dated July 10, 1998. 
Completion of this rework constitutes terminating action to the 
inspection requirements of this AD.
    (e) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, Engine Certification Office. 
Operators shall submit their requests through an appropriate FAA 
Maintenance Inspector, who may add comments and then send it to the 
Manager, Engine Certification Office.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this airworthiness directive, 
if any, may be obtained from the Engine Certification Office.

    (f) The requirements of this AD shall be done in accordance with 
the following PWC SBs:

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                  Document No.                     Pages    Revision                     Date
----------------------------------------------------------------------------------------------------------------
PW500-72-30063..................................      1-5          2  July 10, 1998.
    Total pages: 5.
PW500-72-30044..................................      1-6          2  July 10, 1998.
    Total pages: 6.
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This incorporation by reference was approved by the Director of the 
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 
51. Copies may be obtained from Pratt & Whitney Canada, Inc., 1000 
Marie-Victorin, Longueuil, Quebec, Canada J4G 1A1; Attn: Supervisor, 
Publications Customer Service (01CA4); telephone (514) 647-2705, fax 
(514) 647-2702. Copies may be inspected at the FAA, New England 
Region, Office of the Regional Counsel, 12 New England Executive 
Park, Burlington, MA; or at the Office of the Federal Register, 800 
North Capitol Street, NW, suite 700, Washington, DC.
    (g) This amendment becomes effective October 21, 1998, to all 
persons except those persons to whom it was made immediately 
effective by priority letter AD 98-17-10, issued August 7, 1998, 
which contained the requirements of this amendment.

    Issued in Burlington, Massachusetts, on September 28, 1998.
Diane Romanosky,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 98-26528 Filed 10-5-98; 8:45 am]
BILLING CODE 4910-13-P