[Federal Register: February 20, 2004 (Volume 69, Number 34)]
[Proposed Rules]
[Page 7878-7881]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr20fe04-7]
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Proposed Rules
Federal Register
________________________________________________________________________
This section of the FEDERAL REGISTER contains notices to the public of
the proposed issuance of rules and regulations. The purpose of these
notices is to give interested persons an opportunity to participate in
the rule making prior to the adoption of the final rules.
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[[Page 7878]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 2003-NE-25-AD]
RIN 2120-AA64
Airworthiness Directives; Pratt & Whitney Canada PW206A and
PW206E Turboshaft Engines
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: The FAA proposes to supersede an existing airworthiness
directive (AD) for Pratt & Whitney Canada (PWC) PW206A and PW206E
turboshaft engines. That AD currently requires initial and repetitive
borescope inspections of compressor turbine and power turbine blades
for blade axial shift, and replacement of blade retaining rivets and
certain rotor air seals as terminating action for the repetitive
borescope inspections.
This proposed AD would require the same actions but needs to
clarify the extent of engine disassembly that triggers the required
part replacements. This proposed AD is prompted by reports of engine
shutdowns and emergency landings due to severe vibration, resulting in
exhaust gases escaping from the engine-to-exhaust nozzle interface,
thereby triggering in-flight engine fire warnings. We are proposing
this AD to prevent turbine blade axial shift, which could cause high
levels of vibration, loss of engine torque, in-flight engine shutdown,
and loss of the airframe exhaust duct.
DATES: We must receive any comments on this proposed AD by April 20,
2004.
ADDRESSES: Use one of the following addresses to submit comments on
this proposed AD:
By mail: Federal Aviation Administration (FAA),
New England Region, Office of the Regional Counsel, Attention: Rules
Docket No. 2003-NE-25-AD, 12 New England Executive Park, Burlington, MA
01803-5299.
By fax: (781) 238-7055.
By e-mail: 9-ane-adcomment@faa.gov
You can get the service information identified in this proposed AD
from Pratt & Whitney Canada, 1000 Marie-Victorin, Longueuil, Quebec,
Canada J4G1A1.
You may examine the AD docket, by appointment, 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-25-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.faa.gov/language and 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
On August 4, 2003, the FAA issued airworthiness directive (AD)
2003-16-10, Amendment 39-13263 (68 FR 48544, August 14, 2003), to
require initial and repetitive borescope inspections of compressor
turbine and power turbine blades for blade axial shift. That AD also
required replacement of blade retaining rivets and certain rotor air
seals as terminating action for the repetitive borescope inspections.
That action was prompted by reports of engine shutdowns and emergency
landings due to severe vibration and drops in engine torque, and an
increase in internal engine temperature, triggering in-flight engine
fire warnings. That condition, if not corrected, could result in
turbine blade axial shift, which could cause high levels of vibration,
loss of engine torque, in-flight engine shutdown, and loss of the
airframe exhaust duct.
Comments Received Since AD 2003-16-10 Was Issued
Since that final rule; request for comments was issued, we received
two comments on that AD. We have considered those comments.
Request To Clarify the Extent of Engine Disassembly Required
One commenter requests clarification in the AD of the extent of
engine disassembly that would trigger the part replacements and
clarification of the rework specified in the terminating action. The
commenter states that more extensive disassembly is required to do the
part replacement specified in Part B of PWC SB No. 200-72-28069,
Revision 5, dated February 10, 2003, than to do the part rework
specified in Part A of that SB. The commenter also states that the
triggering event of a shop visit for any reason is too restrictive.
The FAA agrees. We have rewritten the terminating action to be done
at the next engine shop visit when access is available to subassembies,
such as modules, accessories, and components, or at the next engine
overhaul,
[[Page 7879]]
whichever occurs first, but before accumulating 1,800 flight hours from
the effective date of this AD or before December 31, 2009, whichever
occurs first.
Request To Clarify the Preamble
One commenter requests clarification of what prompted the AD. The
commenter suggests that the words describing the actions prompting this
AD be changed to state that the AD is being issued to prevent turbine
blade axial shift, leading to high levels of vibration and possible in-
flight engine shutdown.
The FAA agrees to the suggested changes to the preamble, which have
been incorporated into this document. There have been six emergency
landings due to high vibration levels and in-flight engine fire
warnings, one incident of the loss of the airframe exhaust duct, one
in-flight shutdown, one pilot report of high oil consumption, and one
pilot report of loss of torque. To date, there have been no failures
that have resulted in uncontained engine failures. The aircraft warning
and detection system should preclude uncontained engine failures from
occurring. We agree that the loss of the airframe exhaust duct should
have been referenced in the preamble to the current AD. Therefore, the
preamble of this proposal is written to reference the loss of the
airframe exhaust duct.
Correction To Include No. 4 Bearing Rear Rotor Air Seal
The reference to replacing the No. 4 bearing rear rotor air seal
was inadvertently omitted from the compliance section of the AD. We
have rewritten paragraph (i) of the AD to include replacing of the No.
4 bearing rear rotor air seal.
Relevant Service Information
We have reviewed and approved the technical contents of the
following Pratt & Whitney Canada service documents:
Alert Service Bulletin (ASB) No. PW200-72-
A28242, Revision 1, dated October 2, 2002, that describes procedures
for borescope inspecting of compressor turbine blades and power turbine
blades for axial shift within the disks.
Service Bulletin (SB) No. PW200-72-28069,
Revision 5, dated February 10, 2003, that describes procedures for
replacing compressor turbine blade retaining rivets, the No. 3 bearing
rotor air seal, and the No. 4 bearing front rotor air seal.
SB No. PW200-72-28239, Revision 2, dated
February 10, 2003, that describes procedures for replacing power
turbine blade retaining rivets. Transport Canada, which is the
airworthiness authority for Canada, classified these service bulletins
as mandatory and issued AD CF-2003-06, dated February 4, 2003, in order
to ensure the airworthiness of these PWC PW206A and PW206E turboshaft
engines in Canada.
Bilateral Agreement Information
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. Under this bilateral
airworthiness agreement, Transport Canada has kept the FAA informed of
the situation described above. We have 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.
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. Therefore, we are proposing this AD, which
would require:
Initial and repetitive borescope inspections of
compressor turbine blades and power turbine blades for blade axial
shift within the turbine disks; and
Replacement of blade retaining rivets, the No. 3
bearing rotor air seal, and the No. 4 bearing front rotor air seal as
mandatory terminating action for the repetitive borescope inspections.
You must use the service information described previously to
perform the actions required by this AD.
Changes to 14 CFR Part 39--Effect on the Proposed AD
On July 10, 2002, we issued a new version of 14 CFR part 39 (67 FR
47998, 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 about 130 PWC PW206A and PW206E turboshaft engines of the
affected design in the worldwide fleet. We estimate that 15 engines
installed on airplanes of U.S. registry would be affected by this
proposed AD. We also estimate that it would take about 0.5 work hours
per engine to perform the proposed actions, and that the average labor
rate is $65 per work hour. Required parts would cost about $9,077 per
engine. Based on these figures, we estimate the total cost of the
proposed AD to U.S. operators to be $136,656. The manufacturer has
stated that it may provide replacement parts at no cost to operators.
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-25-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 removing Amendment 39-13263 (68 FR
48544, August 14, 2003) and by adding a new airworthiness directive, to
read as follows:
[[Page 7880]]
Pratt & Whitney Canada: Docket No. 2003-NE-25-AD. Supersedes AD
2003-16-10, Amendment 39-13263.
Comments Due Date
(a) The Federal Aviation Administration (FAA) must receive
comments on this airworthiness directive (AD) action by April 20,
2004.
Affected ADs
(b) This AD supersedes AD 2003-16-10, Amendment 39-13263.
Applicability
(c) This AD applies to Pratt & Whitney Canada (PWC) PW206A and
PW206E turboshaft engines. These PWC engines are installed on, but
not limited to, MD Helicopters Inc. Model MD-900 helicopters.
Unsafe Condition
(d) This AD is prompted by the need to clarify the extent of
engine disassembly that triggers the required part replacements.
This AD is also prompted by reports of engine shutdowns and
emergency landings due to severe vibration, resulting in exhaust
gases escaping from the engine-to-exhaust nozzle interface, thereby
triggering in-flight engine fire warnings. The actions specified in
this AD are intended to prevent turbine blade axial shift, leading
to high levels of vibration, in-flight engine shutdowns and loss of
the airframe exhaust duct.
Compliance
(e) You are responsible for having the actions required by this
AD performed within the compliance times specified unless the
actions have already been done.
Initial Sequence of Borescope Inspections
(f) Perform an initial sequence of borescope inspections of
compressor turbine blades and power turbine blades for blade axial
shift within the turbine disks. Use paragraph 3. of Accomplishment
Instructions of PWC Alert Service Bulletin (ASB) No. PW200-72-
A28242, Revision 1, dated October 2, 2002, for the borescope
inspection and determination of blade shift. Do the inspections at
the following times:
(1) Within 25 flight hours accumulated, or 30 days after the
effective date of this AD, whichever occurs earlier.
(2) After 30 flight hours, but before 50 flight hours
accumulated since inspection of paragraph (f)(1) of this AD.
(3) After 80 flight hours, but before 100 flight hours
accumulated since inspection of paragraph (f)(1) of this AD.
(4) After 180 flight hours, but before 200 flight hours
accumulated since inspection of paragraph (f)(1) of this AD.
Repetitive Borescope Inspections
(g) Thereafter, perform repetitive borescope inspections at
intervals of not less than 280 nor more than 300 flight hours since-
last-inspection. Use paragraph 3. of Accomplishment Instructions of
PWC ASB No. PW200-72-A28242, Revision 1, dated October 2, 2002, for
the borescope inspections and determination of blade shift.
Disposition
(h) If you find any blade shift, remove engine from service
before further flight and perform rivet and rotor air seal
replacements, as specified in paragraphs (i)(1) through (i)(3) of
this AD, to return the engine to service.
Terminating Action
(i) At the next engine shop visit when access is available to
subassembies, such as modules, accessories, and components, or at
the next engine overhaul, whichever occurs first, but before
accumulating 1,800 flight hours from the effective date of this AD
or before December 31, 2009, whichever occurs first, do the
following:
(1) Replace the compressor turbine blade retaining rivets with
new P/N retaining rivets, and the No. 4 bearing rear rotor air seal
with the new P/N No. 4 bearing rear rotor air seal. Use paragraph
3., Part A, of Accomplishment Instructions of SB No. PW200-72-28069,
Revision 5, dated February 10, 2003.
(2) Replace the No. 3 bearing rotating air seal with the new P/N
air seal, and the No. 4 bearing front rotor air seal with the new P/
N No. 4 bearing front rotor air seal. Use paragraph 3., Part B, of
Accomplishment Instructions of SB No. PW200-72-28069, Revision 5,
dated February 10, 2003.
(3) Replace the power turbine blade retaining rivets with new P/
N power turbine blade retaining rivets. Use paragraph 3. of
Accomplishment Instructions of SB No. PW200-72-28239, Revision 2,
dated February 10, 2003.
(j) Completing the actions in paragraphs (i)(1) through (i)(3)
of this AD terminate all inspection requirements of this AD.
Previous Credit
(k) Previous credit is allowed:
(1) For performing the initial sequence for borescope
inspections in paragraph (f) of this AD, that were done using AD
2003-16-10.
(2) For terminating action in paragraphs (i)(1) through (i)(3)
of this AD that was done using Accomplishment Instructions of SB No.
PW200-72-28069, Revision 4, dated December 27, 2000, and
Accomplishment Instructions of SB No. PW200-72-28239, dated
September 5, 2002, or Revision 1, dated December 5, 2002, before the
effective date of this AD.
Alternative Methods of Compliance
(l) 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.
Material Incorporated by Reference
(m) You must use the following Pratt & Whitney Canada Service
Bulletins and Alert Service Bulletin to perform the inspections and
replacement actions required by this AD. The Director of the Federal
Register approved the incorporation by reference of the documents
listed in Table 1 of this AD as of August 29, 2003 (68 FR 48544,
August 14, 2003), in accordance with 5 U.S.C. 552(a) and 1 CFR part
51. You may get a copy from Pratt & Whitney Canada, 1000 Marie-
Victorin, Longueuil, Quebec, Canada J4G1A1. You may review copies at
Federal Aviation Administration (FAA), New England Region, Office of
the Regional Counsel, Attention: Rules Docket No. 2003-NE-25-AD, 12
New England Executive Park, Burlington, MA 01803-5299; or at the
Office of the Federal Register, 800 North Capitol Street, NW., suite
700, Washington, DC. Table 1 follows:
Table 1.--Incorporation by Reference
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Service bulletin Page number(s) Revision Date
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PW200-72-A28242...................... All..................... 1 October 2, 2002.
Total Pages--7.
PW200-72-28069....................... All..................... 5 February 10, 2003.
Total Pages--17.
PW200-72-28239....................... All..................... 2 February 10, 2003.
Total Pages--20.
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[[Page 7881]]
Related Information
(n) Transport Canada issued airworthiness directive CF-2003-06,
dated February 4, 2003, which pertains to the subject of this AD, in
order to assure the airworthiness of these PWC PW206A and PW206E
turboshaft engines in Canada.
Issued in Burlington, Massachusetts, on February 13, 2004.
Peter A. White,
Acting Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. 04-3682 Filed 2-19-04; 8:45 am]
BILLING CODE 4910-13-P