[Federal Register Volume 62, Number 39 (Thursday, February 27, 1997)]
[Rules and Regulations]
[Pages 9068-9070]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-4993]
[[Page 9067]]
_______________________________________________________________________
Part IV
Department of Transportation
_______________________________________________________________________
Federal Aviation Administration
_______________________________________________________________________
14 CFR Part 39
Airworthiness Directives; Pratt & Whitney Canada PT6 Series Turboprop
Engines; Final Rule
Federal Register / Vol. 62, No. 39 / Thursday, February 27, 1997 /
Rules and Regulations
[[Page 9068]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 97-ANE-01; Amendment 39-9936; AD 97-04-12]
RIN 2120-AA64
Airworthiness Directives; Pratt & Whitney Canada PT6 Series
Turboprop Engines
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; request for comments.
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SUMMARY: This amendment adopts a new airworthiness directive (AD) that
is applicable to certain Pratt & Whitney Canada (PWC) PT6 series
turboprop engines. This action requires a one-time visual inspection of
compressor bleed-off valves (BOVs) to determine if an affected
supplier's code number is on the cover; and, if so, this AD requires
the removal of the bleed valve cover assembly from the compressor bleed
valve housing assembly and inspection of the cotter pin and the guide
shaft pin. If the cotter pin or guide shaft pin is not acceptable, this
AD requires modifying the compressor BOV or replacing it with a
serviceable part. This amendment is prompted by reports of two
malfunctions of compressor BOVs that resulted in inflight engine power
reduction. The actions specified in this AD are intended to prevent
engine power reduction due to malfunction of the compressor BOV, which
could result in a forced landing and loss of the aircraft.
DATES: Effective March 14, 1997.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of March 14, 1997.
Comments for inclusion in the Rules Docket must be received on or
before April 28, 1997.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), New England Region, Office of the Assistant Chief
Counsel, Attention: Rules Docket No. 97-ANE-01, 12 New England
Executive Park, Burlington, MA 01803-5299.
The service information referenced in this AD may be obtained from
Pratt & Whitney Canada, 1000 Marie-Victorin, Longueuil, Quebec, Canada
J4G 1A1; telephone (514) 677-9411, fax (514) 647-3620. This information
may be examined at the FAA, New England Region, Office of the Assistant
Chief 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: Diane Cook, Aerospace Engineer, Engine
Certification Office, FAA, Engine and Propeller Directorate, 12 New
England Executive Park, Burlington, MA 01803-5299; telephone (617) 238-
7134, fax (617) 238-7199.
SUPPLEMENTARY INFORMATION: Transport Canada, which is the airworthiness
authority for Canada, recently notified the FAA that an unsafe
condition may exist on certain Pratt & Whitney Canada (PWC) PT6 series
turboprop engines installed on single engine aircraft. Transport Canada
advises that it has received reports of two malfunctions of compressor
bleed-off valves (BOVs) on PWC PT6A-25C series engines, resulting in
inflight engine power reduction. The investigation revealed that the
cause of the compressor BOV malfunction was broken cotter pins. The
debris from the cotter pins interfered with the movement of the BOV
piston, which resulted in the BOV remaining in the closed position. The
cotter pins broke due to stress loading from the guide shaft pin, which
was improperly installed and loose. Further investigation indicates the
compressor BOVs from the two malfunctions are from the same supplier.
All BOVs produced from this supplier, which is approximately 1,000
compressor BOVs since January 1995, are the suspect population. The
compressor BOVs are common to all PWC PT6 series engine models. This
condition, if not corrected, could result in engine power reduction due
to malfunction of the compressor BOV, which could result in a forced
landing and loss of the aircraft.
Pratt & Whitney Canada has issued the following Service Bulletins
(SBs): 14251, Revision 1, dated December 2, 1996; 13287, Revision,
dated December 2, 1996; 12134, Revision 1, dated December, 1996; 4204,
dated December 10, 1996, Original; 3344, Revision 1, dated December 3,
1996; and 1538, Revision 3, dated December 2, 1996. The SBs describe
procedures for visually inspecting BOVs to determine if the affected
supplier's code number (No.) is on the cover. If the code No. is
present, the SB describes the procedures for the removal of the bleed
valve cover assembly from the bleed valve housing assembly, the
inspection of the cotter pin and the guide shaft pin, the installation
of a new compressor valve cover assembly if necessary, the reassembly
of the bleed valve cover assembly to the bleed valve assembly, and the
reidentification of the bleed valve assembly. Transport Canada
classified these SBs as mandatory and issued Emergency AD CF-96-24,
which is applicable to all PT6A engines installed in single engine
aircraft, 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 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.
Since an unsafe condition has been identified that is likely to
exist or develop on other engines of the same type design registered in
the United States, the proposed AD would require, within 100 hours time
in service after the effective date of this AD, but no later than April
2, 1997, a one-time visual inspection of compressor BOVs to determine
if the affected supplier's code No. 8070, is on the cover. No further
action is required if code No. 8070 is not on the cover, or if the
compressor BOV has been marked with the reidentification ``RE71''
adjacent to the part number. If code No. 8070 is found and the
compressor BOV has not been marked for reidentification, this AD
requires inspecting the cotter pin for any wear indications and the
guide shaft pin for any movement described in the applicable SB. If the
cotter pin or guide shaft pin is not acceptable, this AD requires,
prior to further flight, modifying the compressor BOV or replacing it
with a serviceable part. If the conditions of the cotter pin and the
guide shaft pin are acceptable, this AD requires the replacement of the
cotter pin, and the reidentification of the bleed valve assembly in
accordance with the PW SB. The calendar end-date of April 2, 1997, was
determined based upon safety considerations and parts availability. The
actions would be required to be accomplished in accordance with the SBs
described previously.
Since a situation exists that requires the immediate adoption of
this regulation, it is found that notice and opportunity for prior
public comment hereon are impracticable, and that good
[[Page 9069]]
cause exists for making this amendment effective in less than 30 days.
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 97-ANE-01.'' 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 USC 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
97-04-12 Pratt & Whitney Canada: Amendment 39-9936. Docket 97-ANE-
01.
Applicability: Pratt & Whitney Canada (PWC) PT6 series turboprop
engines manufactured after January 1, 1995, or any PT6 series
engines that have had their compressor bleed-off valve (BOV) changed
after January 1, 1995, and which are installed in single-engine
aircraft including, but not limited to the following aircraft: Air
Tractor AT, Ayres Turbo Thrush Commander, Cessna 208 Caravan, Argo
Aircraft G169B, Embraer EMB-312 Tucano, Frakes AF-CAT, Pilatus PC-6,
PC-7, PC-9, and PC-12, Schweitzer AG-CAT, Aerospatiale Socata TBM-
700, and Raytheon (Beech) T-34C.
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 engine power reduction due to malfunction of the
compressor BOV, which could result in a forced landing and loss of
the aircraft, accomplish the following:
(a) Within 100 hours time in service (TIS) after the effective
date of this AD, but no later than April 2, 1997, perform a visual
inspection of compressor BOVs to determine if the affected
supplier's code number (No.) 8070, is on the cover, in accordance
with the following PWC Service Bulletins (SBs), as applicable:
14251, Revision 1, dated December 2, 1996; 13287, Revision 1, dated
December 2, 1996; 12134, Revision 1, dated December 2, 1996; 4204,
dated December 10, 1996, Original; 3344, Revision 1, dated December
3, 1996; and 1538, Revision 3, dated December 2, 1996.
(b) No further action is required if code No. 8070 is not on the
cover of the compressor BOV, or if the compressor BOV has been
marked with the reidentification ``RE71'' adjacent to the part
number.
(c) For compressor BOVs with code No. 8070 and no
reidentification ``RE71'' marking, prior to further flight remove
and inspect the cotter pin for any wear indications and inspect the
guide shaft pin for any movement in accordance with the applicable
SB listed in paragraph (a) of this AD.
(1) If the cotter pin or guide shaft pin is not acceptable in
accordance with the applicable SB listed in paragraph (a) of this
AD, prior to further flight, modify the compressor BOV in accordance
with the applicable SB listed in paragraph (a) of this AD, or
replace it with a serviceable part.
(2) If the cotter pin and the guide shaft pin are acceptable in
accordance with the applicable SB listed in paragraph (a) of this
AD, prior to further flight, replace the cotter pin with a
serviceable part.
(d) Assemble and install the compressor bleed valve cover
assembly on the housing assembly and reidentify the bleed valve
assembly with ``RE71'' in accordance with the applicable SB listed
in paragraph (a) 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. The
request should be forwarded through an appropriate FAA Principal
Maintenance Inspector, who may add comments and then send it to the
Manager, 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) Special flight permits may be issued in accordance with
sections 21.197 and 21.199 of the Federal Aviation Regulations (14
CFR 21.197 and 21.199) to operate the aircraft to a location where
the requirements of this AD can be accomplished.
(g) The actions required by this AD shall be accomplished in
accordance with the following PWC SBs:
[[Page 9070]]
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Document No. Pages Revision Date
----------------------------------------------------------------------------------------------------------------
14251.................................. 1-9 1...................... December 2, 1996.
Total pages: 9...................
13287.................................. 1-11 1...................... December 2, 1996.
Total pages: 11..................
12134.................................. 1-8 1...................... December 2, 1996.
Total pages: 8...................
4204................................... 1-11 Original............... December 10, 1996.
Total pages: 11..................
3344................................... 1-11 1...................... December 3, 1996.
Total pages: 11..................
1538................................... 1-9 3...................... December 2, 1996.
Total pages: 9...................
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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, 1000
Marie-Victorin, Longueuil, Quebec, Canada J4G 1A1; telephone (514)
677-9411, fax (514) 647-3620. Copies may be inspected at the FAA,
New England Region, Office of the Assistant Chief 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.
(h) This amendment becomes effective on March 14, 1997.
Issued in Burlington, Massachusetts, on February 18, 1997.
James C. Jones,
Acting Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. 97-4993 Filed 2-26-97; 9:21 am]
BILLING CODE 4910-13-U
