[Federal Register Volume 75, Number 126 (Thursday, July 1, 2010)]
[Proposed Rules]
[Pages 38052-38056]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2010-16010]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2010-0452; Directorate Identifier 98-ANE-80-AD]
RIN 2120-AA64
Airworthiness Directives; Pratt & Whitney JT8D-209, -217, -217A,
-217C, and -219 Series Turbofan 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 (PW) JT8D-209, -217, -217A, -217C,
and -219 series turbofan engines. That AD requires initial and
repetitive torque inspections of the 3rd stage and 4th stage low-
pressure turbine (LPT) blades for shroud notch wear and replacement of
the blade if wear limits are exceeded. That AD also requires replacing
LPT-to-exhaust case bolts and nuts with bolts and nuts made of Tinidur
material. This proposed AD would require the same actions but would
require replacement of the LPT-to-exhaust case bolts and nuts with
longer bolts made of Tinidur material, with nuts made of Tinidur
material, and installation of crushable sleeve spacers on the bolts.
This proposed AD results from nine reports of failure of Tinidur
material LPT-to-exhaust case bolts since AD 2005-02-03 became
effective. We are proposing this AD to prevent turbine blade failures
that could result in uncontained engine debris and damage to the
airplane.
DATES: We must receive any comments on this proposed AD by August 30,
2010.
ADDRESSES: Use one of the following addresses to comment on this
proposed AD.
Federal eRulemaking Portal: Go to http://www.regulations.gov and follow the instructions for sending your
comments electronically.
Mail: Docket Management Facility, U.S. Department of
Transportation, 1200 New Jersey Avenue, SE., West Building Ground
Floor, Room W12-140, Washington, DC 20590-0001.
Hand Delivery: Deliver to Mail address above between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
Fax: (202) 493-2251.
FOR FURTHER INFORMATION CONTACT: Kevin Dickert, Aerospace Engineer,
Engine Certification Office, FAA, Engine & Propeller Directorate, 12
New England Executive Park, Burlington, MA 01803; e-mail:
[email protected]; telephone (781) 238-7117; fax (781) 238-7199.
SUPPLEMENTARY INFORMATION:
Comments Invited
We invite you to send any written relevant data, views, or
arguments regarding this proposal. Send your comments to an address
listed under ADDRESSES. Include ``Docket No. FAA-2010-0452; Directorate
Identifier 98-ANE-80-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 http://www.regulations.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 Web site, anyone can find and read the comments in any
of our dockets, including, if provided, 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).
Examining the AD Docket
You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Operations office
between 9 a.m. and 5 p.m., Monday through Friday, except Federal
holidays. The AD docket contains this proposed AD, the regulatory
evaluation, any comments received, and other information. The street
address for the Docket Operations office (telephone (800) 647-5527) is
the same as the Mail address provided in the ADDRESSES section.
Comments will be available in the AD docket shortly after receipt.
Discussion
The FAA proposes to amend 14 CFR part 39 by superseding AD 2005-02-
03, Amendment 39-13948 (70 FR 3867, January 27, 2005). That AD requires
torque inspection of the 3rd stage and 4th stage LPT blades for shroud
notch wear and replacement of the blade if wear limits are exceeded.
That AD also requires replacing LPT-to-exhaust case bolts and nuts with
bolts and nuts made of Tinidur material. That AD was the result of
reports of 194 blade fractures since 1991, with 37 of those blade
fractures resulting in LPT case separation, and three reports of
uncontained 3rd stage and 4th stage LPT blade failures with cowl
penetration. That condition, if not corrected, could result in turbine
blade failures that could result in uncontained engine debris and
damage to the airplane.
Actions Since AD 2005-02-03 Was Issued
Since AD 2005-02-03 was issued, we received nine reports of failure
of Tinidur material LPT-to-exhaust case bolts occurring during 3rd and/
or 4th stage blade fracture events. Three of these events resulted in
cowl penetration. The bolts mandated by AD 2005-02-03 do not provide
enough energy absorption during a blade fracture event. PW has
introduced longer bolts made of Tinidur and crushable sleeve spacers
that will increase the energy absorption capability of the fasteners
during a blade fracture event.
Also since AD 2005-02-03 was issued, PW revised Alert Service
Bulletin (ASB) No. JT8D A6224, Revision 5, dated June 11, 2004, with
Revision 6, dated May 3, 2007.
Relevant Service Information
We have reviewed and approved the technical contents of PW ASB No.
JT8D A6224, Revision 6, dated May 3, 2007. That ASB describes
procedures for performing torque inspections of the 3rd and 4th stage
turbine blades.
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. For that reason, we are proposing this AD,
which would require torque inspection of the 3rd stage and 4th stage
LPT blades for shroud notch wear and replacement of the blade if wear
limits are exceeded. This proposed AD would also require the
replacement of LPT-to-exhaust case bolts and nuts with longer bolts
made of Tinidur material, with nuts made of Tinidur material, and
installation of crushable sleeve spacers on the bolts.
[[Page 38053]]
Costs of Compliance
We estimate that this proposed AD would affect 1,143 engines
installed on airplanes of U.S. registry. We also estimate that it would
take about 1 work-hour per engine to perform the proposed blade
inspection, and 1.5 work-hours per engine to replace the LPT-to-exhaust
case bolts and nuts and install the crushable sleeve spacers. Required
bolts, nuts, and sleeve spacers would cost about $4,576 per engine. We
anticipate that 61 engines would require blade replacement each year.
Required blades would cost about $131,560 per engine. The average labor
rate is $85 per work-hour. Based on these figures, we estimate the
total cost of the proposed AD to U.S. operators to be $13,617,671.
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
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 AD:
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, Incorporation by
reference, 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 removing Amendment 39-13948 (70 FR
3867, January 27, 2005) and by adding a new airworthiness directive to
read as follows:
Pratt & Whitney: Docket No. FAA-2010-0452; Directorate Identifier
98-ANE-80-AD.
Comments Due Date
(a) The Federal Aviation Administration (FAA) must receive
comments on this airworthiness directive (AD) action by August 30,
2010.
Affected ADs
(b) This AD supersedes AD 2005-02-03.
Applicability
(c) This AD applies to Pratt & Whitney (PW) JT8D-209, -217, -
217A, -217C, and -219 series turbofan engines. These engines are
installed on, but not limited to, Boeing 727 series and McDonnell
Douglas MD-80 series airplanes.
Unsafe Condition
(d) This AD results from nine reports of failure of Tinidur
material low-pressure turbine (LPT)-to-exhaust case bolts since AD
2005-02-03 became effective. We are issuing this AD to prevent
turbine blade failures that could result in uncontained engine
debris and damage to the airplane.
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.
Requirements of AD 2005-02-03
Initial Torque Inspection for JT8D-209, -217, and -217A Engines
(f) For JT8D-209, -217, and -217A engines, perform the initial
torque inspection of 3rd and 4th stage LPT blades for shroud notch
wear. Use the procedures described in Accomplishment Instructions,
Part 1, Paragraphs 1 through 3, of PW Alert Service Bulletin (ASB)
No. JT8D A6224, Revision 6, dated May 3, 2007, at the applicable
threshold in the following Table 1:
Table 1--Initial Torque Inspection Threshold for JT8D-209, -217, and -
217A Engines
------------------------------------------------------------------------
Hours time-in-
service (TIS) as
of March 3, 2005
Blade type (the effective Inspection threshold
date of AD 2005-
02-03)
------------------------------------------------------------------------
(1) New pre-Service Bulletin Any number....... Within 6,000 hours
(SB) No. 5867 (small notch) TIS.
3rd stage turbine blades.
(2) Refurbished pre-SB No. (i) Fewer than Within 4,000 hours
5867 (small notch) 3rd stage 3,000. TIS.
turbine blades.
(ii) 3,000 or Within 6,000 hours
more. TIS, or within 1,000
hours TIS from March
3, 2005, whichever
occurs first.
(3) New post-SB No. 5867 Any number....... Within 10,000 hours
(large notch) 3rd stage TIS.
turbine blades.
(4) Refurbished post-SB No. (i) Fewer than Within 7,000 hours
5867 (large notch) 3rd stage 6,000. TIS.
turbine blades.
(ii) 6,000 or Within 8,000 hours
more. TIS, or within 1,000
hours TIS from March
3, 2005, whichever
occurs first.
(5) New pre-SB No. 6029 (small Any number....... Within 6,000 hours
notch) 4th stage turbine TIS.
blades.
[[Page 38054]]
(6) Refurbished pre-SB No. (i) Fewer than Within 4,000 hours
6029 (small notch) 4th stage 3,000. TIS.
turbine blades.
(ii) 3,000 or Within 6,000 hours
more. TIS, or within 1,000
hours TIS from March
3, 2005, whichever
occurs first.
(7) New post-SB No. 6029 or Any number....... Within 10,000 hours
new post-SB No. 6308 (large TIS.
notch) 4th stage turbine
blades.
(8) Refurbished post-SB No. (i) Fewer than Within 7,000 hours
6029 or refurbished post-SB 6,000. TIS.
No. 6308 (large notch) 4th
stage turbine blades.
(ii) 6,000 or Within 8,000 hours
more. TIS, or within 1,000
hours TIS from March
3, 2005, whichever
occurs first.
------------------------------------------------------------------------
Repetitive Torque Inspections for JT8D-209, -217, and -217A Engines
(g) For JT8D-209, -217, and -217A engines, perform repetitive
torque inspections of 3rd and 4th stage LPT blades for shroud notch
wear. Use the procedures described in Accomplishment Instructions,
Part 1, Paragraph 1 of PW ASB No. JT8D A6224, Revision 6, dated May
3, 2007, at the applicable intervals in the following Table 2 and
Table 3:
Table 2--3rd Stage Repetitive Torque Inspection Intervals for JT8D-209,
217, and -217A Engines
------------------------------------------------------------------------
Number of
Inspection torque readings readings Disposition
------------------------------------------------------------------------
Greater than or equal to 15 LB- All.............. Repeat torque
IN (1.695 N.m). inspection within
1,000 hours TIS
since last
inspection.
Less than 15 LB-IN (1.695 N.m) One or more...... Repeat torque
but greater than or equal to inspection within
10 LB-IN (1.130 N.m). 500 hours TIS since
last inspection.
Less than 10 LB-IN (1.130 N.m) One to three..... Repeat torque
but greater than or equal to inspection within
5 LB-IN (0.565 N.m). 125 hours TIS since
last inspection.
Less than 10 LB-IN (1.130 N.m) Four or more..... Remove engine from
but greater than or equal to service within 20
5 LB-IN (0.565 N.m). hours TIS since last
inspection.
Less than 5 LB-IN (0.565 N.m). One or more...... Remove engine from
service within 20
hours TIS since last
inspection.
------------------------------------------------------------------------
Table 3--4th Stage Repetitive Torque Inspection Intervals for JT8D-209,
217, and -217A Engines
------------------------------------------------------------------------
Number of
Inspection torque readings readings Disposition
------------------------------------------------------------------------
Greater than or equal to 15 LB- All.............. Repeat torque
IN (1.695 N.m). inspection within
1,000 hours TIS
since last
inspection.
Less than 15 LB-IN (1.695 N.m) One or more...... Repeat torque
but greater than or equal to inspection within
10 LB-IN (1.130 N.m). 500 hours TIS since
last inspection.
Less than 10 LB-IN (1.130 N.m) One to six....... Repeat torque
but greater than or equal to inspection within
5 LB-IN (0.565 N.m). 125 hours TIS since
last inspection.
Less than 10 LB-IN (1.130 N.m) Seven or more.... Remove engine from
but greater than or equal to service within 20
5 LB-IN (0.565 N.m). hours TIS since last
inspection.
Less than 5 LB-IN (0.565 N.m). One or more...... Remove engine from
service within 20
hours TIS since last
inspection.
------------------------------------------------------------------------
(h) Subsequent repeat inspection intervals must not exceed the
previous inspection interval.
JT8D-209, -217, and -217A Engines Removed From Service
(i) JT8D-209, -217, and -217A engines removed from service may
be returned to service after a detailed inspection and repair or
replacement for all blades, of the failed stage, that exceed Engine
Manual limits is done. Information on repairing or replacing turbine
blades can be found in Sections 72-53-12 through 72-53-13 of the
JT8D-200 Engine Manual, Part No. 773128.
Initial Inspection for JT8D-217C and -219 Engines
(j) For JT8D-217C and -219 engines, perform the initial torque
inspection of 4th stage LPT blades for shroud notch wear. Use the
procedures described in Accomplishment Instructions, Part 2,
Paragraphs 1 through 3 of PW ASB No. JT8D A6224, Revision 6 dated
May 3, 2007, at the applicable threshold in the following Table 4:
[[Page 38055]]
Table 4--Initial Torque Inspection Threshold for JT8D-217C and -219
Engines
------------------------------------------------------------------------
TIS as of March
Blade type 3, 2005 Inspection threshold
------------------------------------------------------------------------
(1) New pre-SB No. 6090 (small Any number....... Within 5,000 hours
notch) 4th stage turbine TIS.
blades.
(2) Refurbished pre-SB No. (i) Fewer than Within 4,000 hours
6090 (small notch) 4th stage 3,000. TIS.
turbine blades.
(ii) 3,000 or Within 5,000 hours
more. TIS, or within 1,000
hours TIS from March
3, 2005, whichever
occurs first.
(3) New post-SB No. 6090, new Any number....... Within 10,000 hours
post-SB No. 6402, or new post- TIS.
SB No. 6412 (large notch) 4th
stage turbine blades.
(4) Refurbished ``As-Cast'' Any number....... Within 7,000 hours
post-SB No. 6090, post-SB No. TIS.
6402, or post-SB No. 6412
(large notch) 4th stage
turbine blades.
(5) Refurbished ``Modified'' (i) Fewer than Within 4,000 hours
post-SB No. 6090, post-SB No. 3,000. TIS.
6402, or post-SB No. 6412
(large notch) 4th stage
turbine blades.
(ii) 3,000 or Within 7,000 hours
more. TIS, or within 1,000
hours TIS from March
3, 2005, whichever
occurs first.
------------------------------------------------------------------------
Repetitive Torque Inspections for JT8D-217C and -219 Engines
(k) For JT8D-217C and -219 engines, perform repetitive torque
inspections of 4th stage LPT blades for shroud notch wear. Use the
procedures described in Accomplishment Instructions, Part 2,
Paragraph 1 of PW ASB No. JT8D A6224, Revision 6, dated May 3, 2007,
at the applicable intervals in the following Table 5:
Table 5--Repetitive Torque Inspection Intervals for JT8D-217C and -219
Engines
------------------------------------------------------------------------
Number of
Inspection torque readings readings Disposition
------------------------------------------------------------------------
Greater than or equal to 15 LB- All.............. Repeat torque
IN (1.695 N.m). inspection within
1,000 hours TIS
since last
inspection.
Less than 15 LB-IN (1.695 N.m) One or more...... Repeat torque
but greater than or equal to inspection within
10 LB-IN (1.130 N.m). 500 hours TIS since
last inspection.
Less than 10 LB-IN (1.130 N.m) One to six....... Repeat torque
but greater than or equal to inspection within
5 LB-IN (0.565 N.m). 125 hours TIS since
last inspection.
Less than 10 LB-IN (1.130 N.m) Seven or more.... Remove engine from
but greater than or equal to service within 20
5 LB-IN (0.565 N.m). hours TIS since last
inspection.
Less than 5 LB-IN (0.565 N.m). One or more...... Remove engine from
service within 20
hours TIS since last
inspection.
------------------------------------------------------------------------
(l) Subsequent repeat inspection intervals must not exceed the
previous inspection interval.
JT8D-217C and -219 Engines Removed From Service
(m) JT8D-217C and -219 engines removed from service may be
returned to service after a detailed inspection and repair or
replacement for all blades, of the failed stage, that exceed Engine
Manual limits is done. Information on repairing or replacing turbine
blades can be found in Sections 72-53-12 through 72-53-13 of the
JT8D-200 Engine Manual, Part No. 773128.
Other Criteria for All Engine Models Listed in This AD
(n) Whenever a refurbished or used blade is intermixed with new
blades in a rotor, use the lowest initial inspection threshold that
is applicable.
(o) The initial torque inspection or the repetitive inspection
intervals for a particular stage may not be reset unless the blades
for that stage are refurbished or replaced.
(p) Whenever a used (service run) blade is reinstalled in a
rotor, the previous used time should be subtracted from the initial
torque inspection threshold.
What This AD Changes
LPT-to-Exhaust Case Bolts and Nuts Replacement, and Crushable Sleeve
Spacer Installation
(q) At next accessibility to the LPT-to-Exhaust Case bolts and
nuts, do the following:
(1) Replace the bolts with part number (P/N) MS9557-26 bolts;
and
(2) Replace the nuts with P/N 375095 nuts or P/N 490270 nuts;
and
(3) Install crushable sleeve spacers, P/N 822903, under the head
of the bolts.
(4) Guidance on replacing the bolts and nuts and installing the
crushable sleeve spacers can be found in PW ASB No. JT8D A6494,
Revision 1, dated January 26, 2010.
Previous Credit
(r) Initial inspections performed before the effective date of
this AD using PW ASB No. JT8D A6224, Revision 5, dated June 11,
2004, or Revision 6, dated May 3, 2007, satisfy the initial
inspection requirements of this AD.
Definitions
(s) For the purpose of this AD, refurbishment is defined as
restoration of either the shrouds or blade retwist or both, per the
JT8D-200 Engine Manual, Part No. 773128.
(t) For the purpose of this AD, ``As-Cast'' refers to blades
that were machined from new castings and ``Modified'' refers to
blades that were derived from the pre-SB No. 6090 configuration.
(u) For the purpose of this AD, ``accessibility to the LPT-to-
exhaust case bolts'' refers to when the engine is disassembled
sufficiently to give access to the LPT-to-exhaust case bolts, which
is whenever the inner turbine fan ducts are removed.
Alternative Methods of Compliance
(v) The Manager, Engine Certification Office, has the authority
to approve alternative methods of compliance (AMOCs) for this AD if
requested using the procedures found in 14 CFR 39.19. AMOCs approved
for the initial and repetitive inspection requirements of AD 2005-
02-03 are approved as AMOCs for this AD.
Related Information
(w) Contact Kevin Dickert, Aerospace Engineer, Engine
Certification Office, FAA, Engine & Propeller Directorate, 12 New
England Executive Park, Burlington, MA
[[Page 38056]]
01803; e-mail: [email protected]; telephone (781) 238-7117; fax
(781) 238-7199, for more information about this AD.
(x) Contact Pratt & Whitney, 400 Main St., East Hartford, CT
06108; telephone (860) 565-8770, fax (860) 565-4503, for a copy of
the service information referenced in this AD.
Issued in Burlington, Massachusetts, on June 22, 2010.
Peter A. White,
Assistant Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. 2010-16010 Filed 6-30-10; 8:45 am]
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