Airworthiness Directives; Pratt & Whitney (PW) JT9D-7R4 Series Turbofan Engines, 4964-4966 [E7-1707]
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4964
Proposed Rules
Federal Register
Vol. 72, No. 22
Friday, February 2, 2007
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.
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA–2006–23742; Directorate
Identifier 2005–NE–53–AD]
RIN 2120–AA64
Airworthiness Directives; Pratt &
Whitney (PW) JT9D–7R4 Series
Turbofan Engines
Federal Aviation
Administration (FAA), Department of
Transportation (DOT).
ACTION: Supplemental notice of
proposed rulemaking (NPRM);
reopening of comment period.
ycherry on PROD1PC64 with PROPOSALS
AGENCY:
SUMMARY: This supplemental NPRM
revises an earlier proposed
airworthiness directive (AD) for PW
JT9D–7R4G2 series turbofan engines.
That proposed AD would have required
replacing the old configuration 2nd
stage high pressure turbine (HPT) air
seal assembly with a new design 2nd
stage HPT air seal assembly that
increases cooling air flow. That
proposed AD resulted from a report of
an uncontained failure of the 2nd stage
HPT air seal assembly, caused by the air
seal assembly brace disengaging from
the air seal, due to insufficient cooling
air flow. This supplemental NPRM
revises the proposed AD by proposing to
include additional models of the PW
JT9D–7R4 turbofan engines in the
applicability, requiring a visual and a
fluorescent penetrant inspection of the
air seal assembly, replacing the 2nd
stage HPT vane assemblies, and
reopening the comment period. This
NPRM results from comments to the
proposed AD. We are proposing this AD
to prevent uncontained failure of the
2nd stage HPT air seal assembly, leading
to engine in-flight shutdown and
damage to the airplane.
DATES: We must receive any comments
on this proposed AD by April 3, 2007.
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14:13 Feb 01, 2007
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Use one of the following
addresses to comment on this proposed
AD.
• DOT Docket Web site: Go to https://
dms.dot.gov and follow the instructions
for sending your comments
electronically.
• Government-wide rulemaking Web
site: Go to https://www.regulations.gov
and follow the instructions for sending
your comments electronically.
• Mail: Docket Management Facility;
U.S. Department of Transportation, 400
Seventh Street, SW., Nassif Building,
Room PL–401, Washington, DC 20590–
0001.
• Fax: (202) 493–2251.
• Hand Delivery: Room PL–401 on
the plaza level of the Nassif Building,
400 Seventh Street, SW., Washington,
DC, between 9 a.m. and 5 p.m., Monday
through Friday, except Federal holidays.
You can get the service information
identified in this proposed AD from
Pratt & Whitney, 400 Main St., East
Hartford, CT 06108; telephone (860)
565–8770; fax (860) 565–4503.
You may examine the comments on
this proposed AD in the AD docket on
the Internet at https://dms.dot.gov.
FOR FURTHER INFORMATION CONTACT:
Mark Riley, Aerospace Engineer, Engine
Certification Office, FAA, Engine and
Propeller Directorate, 12 New England
Executive Park, Burlington, MA 01803;
telephone (781) 238–7758, fax (781)
238–7199.
SUPPLEMENTARY INFORMATION:
ADDRESSES:
Comments Invited
We invite you to send us any written
relevant data, views, or arguments
regarding this proposal. Send your
comments to an address listed under
ADDRESSES. Include ‘‘Docket No. FAA–
2006–23742; Directorate Identifier
2005–NE–53–AD’’ in the subject line of
your comments. We specifically invite
comments on the overall regulatory,
economic, environmental, and energy
aspects of the proposed AD. We will
consider all comments received by the
closing date and may amend the
proposed AD in light of those
comments.
We will post all comments we
receive, without change, to https://
dms.dot.gov, including any personal
information you provide. We will also
post a report summarizing each
substantive verbal contact with FAA
personnel concerning this proposed AD.
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Fmt 4702
Sfmt 4702
Using the search function of the DOT
Web site, anyone can find and read the
comments in any of our dockets,
including the name of the individual
who sent the comment (or signed the
comment on behalf of an association,
business, labor union, etc.). You may
review the DOT’s complete Privacy Act
Statement in the Federal Register
published on April 11, 2000 (65 FR
19477–78) or you may visit https://
dms.dot.gov.
Examining the AD Docket
You may examine the docket that
contains the proposal, any comments
received and, any final disposition in
person at the DOT Docket Offices
between 9 a.m. and 5 p.m., Monday
through Friday, except Federal holidays.
The Docket Office (telephone (800) 647–
5227) is located on the plaza level of the
Department of Transportation Nassif
Building at the street address stated in
ADDRESSES. Comments will be available
in the AD docket shortly after the
Docket Management Facility receives
them.
Discussion
On April 19, 2006, we issued a
proposal to amend part 39 of the Code
of Federal Regulations (14 CFR part 39)
to add an AD, applicable to PW JT9D–
7R4G2 turbofan engines. The proposed
AD published as an NPRM in the
Federal Register on April 26, 2006 (71
FR 24613). That NPRM would have
required at the next HPT module
overhaul, replacing the 2nd stage HPT
air seal assembly, P/N 815097, with a
new configuration 2nd stage HPT air
seal assembly that increases cooling air
flow, either by installing a new 2nd
stage air seal assembly or modifying the
old configuration 2nd stage seal
assembly. That NPRM resulted from two
reports of failure of the 2nd stage HPT
air seal assembly, part number (P/N)
815097, installed in JT9D–7R4G2
turbofan engines. That condition, if not
corrected, could result in uncontained
failure of the 2nd stage HPT air seal
assembly, leading to engine in-flight
shutdown and damage to the airplane.
Since we issued that NPRM, we
received comments to add additional
models of the PW JT9D–7R4 series
turbofan engines to the applicability for
this proposed AD. Also, even though we
added new engine models, our changes
to the required actions reduced the
number of engines that are affected and
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Federal Register / Vol. 72, No. 22 / Friday, February 2, 2007 / Proposed Rules
the total cost of this proposed AD to the
U.S. registered fleet.
Since this change expands the scope
of the originally proposed rule, we
determined that it is necessary to reopen
the comment period to provide
additional opportunity for public
comment.
Comments
We provided the public the
opportunity to participate in the
development of this proposed AD. We
have considered the comments received.
ycherry on PROD1PC64 with PROPOSALS
Request to Expand the Applicability
Two commenters, Pratt & Whitney
and FedEx, ask us to expand the
applicability to include the JT9D–
7R4E1, –7R4E4, and –7R4H1. The
commenters point out that the
additional engine models are specified
in PW Alert Service Bulletin (ASB)
JT9D–7R4–A72–596, dated September
15, 2005. We agree. We added the JT9D–
7R4E1, –7R4E4, and –7R4H4 engine
models to the applicability for this
proposed AD.
Requests for Changes to the Costs of
Compliance
One commenter, FedEx, ask us to
revise the Costs of Compliance to
include the expanded number of
engines from adding the additional
JT9D–7R4 engine models. The
commenter states that the existing
Economic impact analysis for the
proposed AD considered only the JT9D–
7R4G2 engine model.
We agree. We revised the Costs of
Compliance section to include all
affected JT9D–7R4 engine models.
However, updated information from the
engine manufacturer confirmed that the
number of engines affected actually
decreased, which results in reduced cost
to the operators.
The same commenter asks us to
include the cost of material required to
incorporate. The commenter estimates
that material cost as $18,000 per engine.
We do not agree. We provide an
estimated material cost of $5,400 per
engine in the Costs of Compliance in the
proposed AD. Parts include new 2nd
stage HPT vane covers, P/N 822734, and
rivets, P/N ST1219–213, that are
required to modify the 2nd stage HPT
vane cluster assemblies as specified in
ASB JT9D–7R4–A72–596.
One commenter, Northwest Airlines,
states the Cost of Compliance in the
proposed AD is understated. The
commenter states that the Costs of
Compliance should include the cost to
repair the honeycomb air seal land that
is riveted to the 2nd stage vane clusters,
which typically require restoring to
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14:13 Feb 01, 2007
Jkt 211001
maintain rotating knife edge-to-seal land
clearances. The commenter states the
FAA should include the maintenance
and repair costs incurred when
exposing the parts.
We don’t agree. The Costs of
Compliance in the proposed AD doesn’t
include costs associated with parts that
require replacement or repair due to
typical wear or damage.
Request to Use a Shorter Rivet in the
2nd Stage Scaling Ring Assembly
One commenter, Japan Air Lines, asks
that we allow using a shorter rivet, part
number (P/N) ST1219–212, instead of
rivet, P/N ST12199–213, for the 2nd
stage turbine air sealing ring segment
assembly, P/N 795187, when
incorporating SB JT9D–7R4–A72–596.
Japan Air Lines states that PW has
approved using the shorter rivet with air
sealing ring segment assembly 795187.
We partially agree. Because we are
now proposing only to require removing
the reduced air flow 2nd stage HPT vane
assemblies, P/Ns 797282, 796972,
800082, 800072, 803182, 803282, and
822582, and we don’t propose to require
modifying the vane assemblies, the
commenter can use the shorter rivet
approved by PW. We don’t need to
approve it as an alternative method of
compliance.
Request to Change the Compliance
Time
One commenter, Northwest Airlines,
asks us to change the compliance time
from the next exposure of the HPT
module to next exposure of the 2nd
stage HPT vanes. The commenter states
that changing the definition would align
the compliance time with the definition
of next exposure.
We don’t agree. The intent of the
proposed AD is to require inspecting the
HPT 2nd stage HPT air seal and
removing the reduced cooling flow 2nd
stage HPT vane assemblies when the
HPT module is exposed. The HPT
module is exposed when the 1st or 2nd
stage HPT rotors are removed from the
HPT module assembly, not when the
2nd stage HPT vane assemblies are
removed from the HPT case.
Request to Remove or Change
Paragraph (d) of the Proposed AD
One commenter, Northwest Airlines,
asks that we remove or change
paragraph (d) of the proposed AD. The
commenter states that as written, the
paragraph requires reidentifying the
next higher assembly, HPT case
assembly, based on P/Ns installed in the
module. The commenter states that
including the P/N configuration of the
top level assembly is not necessary.
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4965
We agree. We removed the
requirement to use PW ASB JT9D–7R4–
A72–596 to replace the vane assembly.
Relevant Service Information
We have reviewed and approved the
technical contents of PW Alert Service
Bulletin JT9D–7R4–A72–596, dated
September 15, 2005. That Alert Service
Bulletin describes procedures for
replacing 2nd stage HPT air seal
assembly, P/N 815097, with a new
configuration 2nd stage HPT air seal
assembly that increases cooling air flow,
either by installing a new 2nd stage air
seal assembly or modifying the old
configuration 2nd stage HPT seal
assembly.
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. We are proposing this AD,
which would require at the next HPT
module exposure:
• Visual and fluorescent penetrant
inspections of the 2nd stage HPT air seal
assembly, P/N 815097, and
• Removing the reduced cooling flow
2nd stage HPT vane assemblies.
Costs of Compliance
We estimate that this proposed AD
would affect 85 PW JT9D–7R4 series
turbofan engines installed on airplanes
U.S. registry. We also estimate that it
would take about 65.5 work-hours per
engine to perform the proposed actions,
and that the average labor rate is $80 per
work-hour. Required parts would cost
about $5,400 per engine. Based on these
figures, we estimate the total cost of the
proposed AD to U.S. operators to be
$904,400.
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
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Federal Register / Vol. 72, No. 22 / Friday, February 2, 2007 / Proposed Rules
that is likely to exist or develop on
products identified in this rulemaking
action.
installed on, but not limited to, Boeing 747–
200B, –200C, –200F, and –300 airplanes.
ENVIRONMENTAL PROTECTION
AGENCY
Unsafe Condition
Regulatory Findings
(d) This AD results from a report of an
uncontained failure of the 2nd stage high
pressure turbine (HPT) air seal assembly,
caused by the air seal assembly brace
disengaging from the air seal, due to
insufficient cooling air flow. We are issuing
this AD to prevent uncontained failure of the
2nd stage HPT air seal assembly, leading to
engine in-flight shutdown and damage to the
airplane.
40 CFR Part 80
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 regulatory evaluation
of the estimated costs to comply with
this proposed AD. See the ADDRESSES
section for a location to examine the
regulatory evaluation.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation
safety, Safety.
The Proposed Amendment
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
(e) You are responsible for having the
actions required by this AD performed at the
next HPT module exposure after the effective
date of this AD, unless the actions have
already been done.
(f) At the next HPT module exposure,
perform a visual inspection and a fluorescent
penetrant inspection of the 2nd stage HPT air
seal assembly part number (P/N) 815097. Use
the engine maintenance manual to perform
the inspections.
(g) At the next HPT module exposure,
remove reduced cooling flow 2nd stage HPT
vane assemblies P/Ns 797282, 796972,
800082, 800072, 803182, 803182, 803282,
and 822582. Pratt & Whitney Alert Service
Bulletin JT9D–7R4–A72–596, dated
September 15, 2005, contains information for
modifying the reduced cooling flow 2nd
stage HPT vane assemblies.
Definition
(h) The manufacturer defines an HPT
module exposure as removing the 1st stage
HPT rotor and 2nd stage HPT rotor from the
HPT case.
Alternative Methods of Compliance
(i) 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.
1. The authority citation for part 39
continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
§ 39.13
Compliance
[Amended]
2. The FAA amends § 39.13 by adding
the following new airworthiness
directive:
Pratt & Whitney: Docket No. FAA–2006–
23742; Directorate Identifier 2006–NE–
39–AD.
Comments Due Date
(a) The Federal Aviation Administration
(FAA) must receive comments on this
airworthiness directive (AD) action by April
3, 2007.
Related Information
(j) Pratt & Whitney Alert Service Bulletin
JT9D–7R4–A72–596, dated September 15,
2005, contains information for modifying the
reduced cooling flow 2nd stage HPT vane
assemblies.
Issued in Burlington, Massachusetts, on
January 26, 2007.
Peter A. White,
Acting Manager, Engine and Propeller
Directorate, Aircraft Certification Service.
[FR Doc. E7–1707 Filed 2–1–07; 8:45 am]
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BILLING CODE 4910–13–P
Affected ADs
(b) None.
Applicability
(c) This AD applies to Pratt & Whitney
(PW) JT9D–74R4E1, –74R4E4, –74R4G2, and
–74R4H1 turbofan engines. These engines are
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[EPA–HQ–OAR–2006–0841; FRL–8275–7]
Regulation of Fuels and Fuel
Additives: Extension of the
Reformulated Gasoline Program to the
East St. Louis, Illinois Ozone
Nonattainment Area
Environmental Protection
Agency (EPA).
ACTION: Notice of public hearing.
AGENCY:
SUMMARY: This action announces the
date, time and place for a public hearing
on the Proposed Rulemaking entitled
‘‘Extension of the Reformulated
Gasoline Program to the East St. Louis,
Illinois Ozone Nonattainment Area’’
published on December 27, 2006 (71 FR
77690).
DATES: EPA will conduct a public
hearing for the December 27, 2006
Proposed Rule on Wednesday, February
21, 2007 from 9 a.m–12:30 p.m. in the
Lake Huron conference room of the
Metcalfe Federal Building in Chicago,
Illinois. If needed, testimony will
resume from 1 p.m. until 4:30 p.m. in
the Lake Erie conference room.
The comment period on the December
27, 2006 Proposed Rule will extend
until March 23, 2007.
ADDRESSES: The public hearing will be
held at EPA Region 5’s Conference and
Training Center, located on the 12th
floor of the Metcalfe Federal Building at
77 W. Jackson Boulevard, Chicago, IL.
Additional directions and visitor
information can be found at: https://
www.epa.gov/region5/visitor/index.htm.
FOR FURTHER INFORMATION CONTACT: Kurt
Gustafson, Transportation and Regional
Programs Division (6405–J), U.S.
Environmental Protection Agency, 1200
Pennsylvania Ave, NW., Washington,
DC 20460. Telephone: (202) 343–9219.
E-mail: gustafson.kurt@epa.gov.
SUPPLEMENTARY INFORMATION: For
further information on this matter,
please refer to EPA’s December 27, 2006
Federal Register Notice of Proposed
Rulemaking at 71 FR 77690.
Anyone who wants to present
testimony about this proposal at the
public hearing (see DATES) should, if
possible, notify the contact person listed
in the FOR FURTHER INFORMATION
CONTACT section of this proposal at least
seven days prior to the day of the
hearing. The contact person should be
given an estimate of the time required
for the presentation of testimony. A
sign-up sheet will be available at the
registration table the morning of the
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Agencies
[Federal Register Volume 72, Number 22 (Friday, February 2, 2007)]
[Proposed Rules]
[Pages 4964-4966]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E7-1707]
========================================================================
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.
========================================================================
Federal Register / Vol. 72, No. 22 / Friday, February 2, 2007 /
Proposed Rules
[[Page 4964]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2006-23742; Directorate Identifier 2005-NE-53-AD]
RIN 2120-AA64
Airworthiness Directives; Pratt & Whitney (PW) JT9D-7R4 Series
Turbofan Engines
AGENCY: Federal Aviation Administration (FAA), Department of
Transportation (DOT).
ACTION: Supplemental notice of proposed rulemaking (NPRM); reopening of
comment period.
-----------------------------------------------------------------------
SUMMARY: This supplemental NPRM revises an earlier proposed
airworthiness directive (AD) for PW JT9D-7R4G2 series turbofan engines.
That proposed AD would have required replacing the old configuration
2nd stage high pressure turbine (HPT) air seal assembly with a new
design 2nd stage HPT air seal assembly that increases cooling air flow.
That proposed AD resulted from a report of an uncontained failure of
the 2nd stage HPT air seal assembly, caused by the air seal assembly
brace disengaging from the air seal, due to insufficient cooling air
flow. This supplemental NPRM revises the proposed AD by proposing to
include additional models of the PW JT9D-7R4 turbofan engines in the
applicability, requiring a visual and a fluorescent penetrant
inspection of the air seal assembly, replacing the 2nd stage HPT vane
assemblies, and reopening the comment period. This NPRM results from
comments to the proposed AD. We are proposing this AD to prevent
uncontained failure of the 2nd stage HPT air seal assembly, leading to
engine in-flight shutdown and damage to the airplane.
DATES: We must receive any comments on this proposed AD by April 3,
2007.
ADDRESSES: Use one of the following addresses to comment on this
proposed AD.
DOT Docket Web site: Go to https://dms.dot.gov and follow
the instructions for sending your comments electronically.
Government-wide rulemaking Web site: Go to https://www.regulations.gov and follow the instructions for sending your
comments electronically.
Mail: Docket Management Facility; U.S. Department of
Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401,
Washington, DC 20590-0001.
Fax: (202) 493-2251.
Hand Delivery: Room PL-401 on the plaza level of the
Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
You can get the service information identified in this proposed AD
from Pratt & Whitney, 400 Main St., East Hartford, CT 06108; telephone
(860) 565-8770; fax (860) 565-4503.
You may examine the comments on this proposed AD in the AD docket
on the Internet at https://dms.dot.gov.
FOR FURTHER INFORMATION CONTACT: Mark Riley, Aerospace Engineer, Engine
Certification Office, FAA, Engine and Propeller Directorate, 12 New
England Executive Park, Burlington, MA 01803; telephone (781) 238-7758,
fax (781) 238-7199.
SUPPLEMENTARY INFORMATION:
Comments Invited
We invite you to send us any written relevant data, views, or
arguments regarding this proposal. Send your comments to an address
listed under ADDRESSES. Include ``Docket No. FAA-2006-23742;
Directorate Identifier 2005-NE-53-AD'' in the subject line of your
comments. We specifically invite comments on the overall regulatory,
economic, environmental, and energy aspects of the proposed AD. We will
consider all comments received by the closing date and may amend the
proposed AD in light of those comments.
We will post all comments we receive, without change, to https://dms.dot.gov, including any personal information you provide. We will
also post a report summarizing each substantive verbal contact with FAA
personnel concerning this proposed AD. Using the search function of the
DOT Web site, anyone can find and read the comments in any of our
dockets, including the name of the individual who sent the comment (or
signed the comment on behalf of an association, business, labor union,
etc.). You may review the DOT's complete Privacy Act Statement in the
Federal Register published on April 11, 2000 (65 FR 19477-78) or you
may visit https://dms.dot.gov.
Examining the AD Docket
You may examine the docket that contains the proposal, any comments
received and, any final disposition in person at the DOT Docket Offices
between 9 a.m. and 5 p.m., Monday through Friday, except Federal
holidays. The Docket Office (telephone (800) 647-5227) is located on
the plaza level of the Department of Transportation Nassif Building at
the street address stated in ADDRESSES. Comments will be available in
the AD docket shortly after the Docket Management Facility receives
them.
Discussion
On April 19, 2006, we issued a proposal to amend part 39 of the
Code of Federal Regulations (14 CFR part 39) to add an AD, applicable
to PW JT9D-7R4G2 turbofan engines. The proposed AD published as an NPRM
in the Federal Register on April 26, 2006 (71 FR 24613). That NPRM
would have required at the next HPT module overhaul, replacing the 2nd
stage HPT air seal assembly, P/N 815097, with a new configuration 2nd
stage HPT air seal assembly that increases cooling air flow, either by
installing a new 2nd stage air seal assembly or modifying the old
configuration 2nd stage seal assembly. That NPRM resulted from two
reports of failure of the 2nd stage HPT air seal assembly, part number
(P/N) 815097, installed in JT9D-7R4G2 turbofan engines. That condition,
if not corrected, could result in uncontained failure of the 2nd stage
HPT air seal assembly, leading to engine in-flight shutdown and damage
to the airplane.
Since we issued that NPRM, we received comments to add additional
models of the PW JT9D-7R4 series turbofan engines to the applicability
for this proposed AD. Also, even though we added new engine models, our
changes to the required actions reduced the number of engines that are
affected and
[[Page 4965]]
the total cost of this proposed AD to the U.S. registered fleet.
Since this change expands the scope of the originally proposed
rule, we determined that it is necessary to reopen the comment period
to provide additional opportunity for public comment.
Comments
We provided the public the opportunity to participate in the
development of this proposed AD. We have considered the comments
received.
Request to Expand the Applicability
Two commenters, Pratt & Whitney and FedEx, ask us to expand the
applicability to include the JT9D-7R4E1, -7R4E4, and -7R4H1. The
commenters point out that the additional engine models are specified in
PW Alert Service Bulletin (ASB) JT9D-7R4-A72-596, dated September 15,
2005. We agree. We added the JT9D-7R4E1, -7R4E4, and -7R4H4 engine
models to the applicability for this proposed AD.
Requests for Changes to the Costs of Compliance
One commenter, FedEx, ask us to revise the Costs of Compliance to
include the expanded number of engines from adding the additional JT9D-
7R4 engine models. The commenter states that the existing Economic
impact analysis for the proposed AD considered only the JT9D-7R4G2
engine model.
We agree. We revised the Costs of Compliance section to include all
affected JT9D-7R4 engine models. However, updated information from the
engine manufacturer confirmed that the number of engines affected
actually decreased, which results in reduced cost to the operators.
The same commenter asks us to include the cost of material required
to incorporate. The commenter estimates that material cost as $18,000
per engine.
We do not agree. We provide an estimated material cost of $5,400
per engine in the Costs of Compliance in the proposed AD. Parts include
new 2nd stage HPT vane covers, P/N 822734, and rivets, P/N ST1219-213,
that are required to modify the 2nd stage HPT vane cluster assemblies
as specified in ASB JT9D-7R4-A72-596.
One commenter, Northwest Airlines, states the Cost of Compliance in
the proposed AD is understated. The commenter states that the Costs of
Compliance should include the cost to repair the honeycomb air seal
land that is riveted to the 2nd stage vane clusters, which typically
require restoring to maintain rotating knife edge-to-seal land
clearances. The commenter states the FAA should include the maintenance
and repair costs incurred when exposing the parts.
We don't agree. The Costs of Compliance in the proposed AD doesn't
include costs associated with parts that require replacement or repair
due to typical wear or damage.
Request to Use a Shorter Rivet in the 2nd Stage Scaling Ring Assembly
One commenter, Japan Air Lines, asks that we allow using a shorter
rivet, part number (P/N) ST1219-212, instead of rivet, P/N ST12199-213,
for the 2nd stage turbine air sealing ring segment assembly, P/N
795187, when incorporating SB JT9D-7R4-A72-596. Japan Air Lines states
that PW has approved using the shorter rivet with air sealing ring
segment assembly 795187.
We partially agree. Because we are now proposing only to require
removing the reduced air flow 2nd stage HPT vane assemblies, P/Ns
797282, 796972, 800082, 800072, 803182, 803282, and 822582, and we
don't propose to require modifying the vane assemblies, the commenter
can use the shorter rivet approved by PW. We don't need to approve it
as an alternative method of compliance.
Request to Change the Compliance Time
One commenter, Northwest Airlines, asks us to change the compliance
time from the next exposure of the HPT module to next exposure of the
2nd stage HPT vanes. The commenter states that changing the definition
would align the compliance time with the definition of next exposure.
We don't agree. The intent of the proposed AD is to require
inspecting the HPT 2nd stage HPT air seal and removing the reduced
cooling flow 2nd stage HPT vane assemblies when the HPT module is
exposed. The HPT module is exposed when the 1st or 2nd stage HPT rotors
are removed from the HPT module assembly, not when the 2nd stage HPT
vane assemblies are removed from the HPT case.
Request to Remove or Change Paragraph (d) of the Proposed AD
One commenter, Northwest Airlines, asks that we remove or change
paragraph (d) of the proposed AD. The commenter states that as written,
the paragraph requires reidentifying the next higher assembly, HPT case
assembly, based on P/Ns installed in the module. The commenter states
that including the P/N configuration of the top level assembly is not
necessary.
We agree. We removed the requirement to use PW ASB JT9D-7R4-A72-596
to replace the vane assembly.
Relevant Service Information
We have reviewed and approved the technical contents of PW Alert
Service Bulletin JT9D-7R4-A72-596, dated September 15, 2005. That Alert
Service Bulletin describes procedures for replacing 2nd stage HPT air
seal assembly, P/N 815097, with a new configuration 2nd stage HPT air
seal assembly that increases cooling air flow, either by installing a
new 2nd stage air seal assembly or modifying the old configuration 2nd
stage HPT seal assembly.
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. We are proposing this AD, which would require
at the next HPT module exposure:
Visual and fluorescent penetrant inspections of the 2nd
stage HPT air seal assembly, P/N 815097, and
Removing the reduced cooling flow 2nd stage HPT vane
assemblies.
Costs of Compliance
We estimate that this proposed AD would affect 85 PW JT9D-7R4
series turbofan engines installed on airplanes U.S. registry. We also
estimate that it would take about 65.5 work-hours per engine to perform
the proposed actions, and that the average labor rate is $80 per work-
hour. Required parts would cost about $5,400 per engine. Based on these
figures, we estimate the total cost of the proposed AD to U.S.
operators to be $904,400.
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
[[Page 4966]]
that is likely to exist or develop on products identified in this
rulemaking action.
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 regulatory evaluation of the estimated costs to
comply with this proposed AD. See the ADDRESSES section for a location
to examine the regulatory evaluation.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
The Proposed Amendment
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: Docket No. FAA-2006-23742; Directorate Identifier
2006-NE-39-AD.
Comments Due Date
(a) The Federal Aviation Administration (FAA) must receive
comments on this airworthiness directive (AD) action by April 3,
2007.
Affected ADs
(b) None.
Applicability
(c) This AD applies to Pratt & Whitney (PW) JT9D-74R4E1, -
74R4E4, -74R4G2, and -74R4H1 turbofan engines. These engines are
installed on, but not limited to, Boeing 747-200B, -200C, -200F, and
-300 airplanes.
Unsafe Condition
(d) This AD results from a report of an uncontained failure of
the 2nd stage high pressure turbine (HPT) air seal assembly, caused
by the air seal assembly brace disengaging from the air seal, due to
insufficient cooling air flow. We are issuing this AD to prevent
uncontained failure of the 2nd stage HPT air seal assembly, leading
to engine in-flight shutdown and damage to the airplane.
Compliance
(e) You are responsible for having the actions required by this
AD performed at the next HPT module exposure after the effective
date of this AD, unless the actions have already been done.
(f) At the next HPT module exposure, perform a visual inspection
and a fluorescent penetrant inspection of the 2nd stage HPT air seal
assembly part number (P/N) 815097. Use the engine maintenance manual
to perform the inspections.
(g) At the next HPT module exposure, remove reduced cooling flow
2nd stage HPT vane assemblies P/Ns 797282, 796972, 800082, 800072,
803182, 803182, 803282, and 822582. Pratt & Whitney Alert Service
Bulletin JT9D-7R4-A72-596, dated September 15, 2005, contains
information for modifying the reduced cooling flow 2nd stage HPT
vane assemblies.
Definition
(h) The manufacturer defines an HPT module exposure as removing
the 1st stage HPT rotor and 2nd stage HPT rotor from the HPT case.
Alternative Methods of Compliance
(i) 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.
Related Information
(j) Pratt & Whitney Alert Service Bulletin JT9D-7R4-A72-596,
dated September 15, 2005, contains information for modifying the
reduced cooling flow 2nd stage HPT vane assemblies.
Issued in Burlington, Massachusetts, on January 26, 2007.
Peter A. White,
Acting Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. E7-1707 Filed 2-1-07; 8:45 am]
BILLING CODE 4910-13-P