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[Federal Register: July 1, 2010 (Volume 75, Number 126)]
[Proposed Rules]               
[Page 38052-38056]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr01jy10-23]                         

=======================================================================
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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).

-----------------------------------------------------------------------

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: 
kevin.dickert@faa.gov; 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: kevin.dickert@faa.gov; 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]
BILLING CODE 4910-13-P
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