[Federal Register Volume 59, Number 231 (Friday, December 2, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-28374]


[[Page Unknown]]

[Federal Register: December 2, 1994]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 91-ANE-39; Amendment 39-9065; AD 94-23-03]

 

Airworthiness Directives; Pratt & Whitney JT8D Series Turbofan 
Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to Pratt & Whitney (PW) JT8D series turbofan engines, that 
requires installation and periodic inspection of temperature indicators 
installed on the No. 4 and 5 bearing compartment scavenge oil tube and 
performance of any necessary corrective action. This amendment is 
prompted by reports of high pressure turbine (HPT) shaft fractures 
caused by oil fires that resulted from internal leakage of thirteenth 
stage compressor discharge air into the No. 4 and 5 bearing 
compartment. The actions specified by this AD are intended to prevent 
fracture of the HPT shaft, which can result in uncontained release of 
engine fragments, engine fire, inflight engine shutdown, or possible 
aircraft damage.

DATES: Effective January 31, 1995.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of January 31, 1995.

ADDRESSES: The service information referenced in this AD may be 
obtained from Pratt & Whitney, Technical Publications Department, M/S 
132-30, 400 Main Street, East Hartford, CT 06108. This information may 
be examined at the Federal Aviation Administration (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: Mark A. Rumizen, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803-5299; telephone (617) 
238-7137, fax (617) 238-7199.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to Pratt & Whitney (PW) JT8D series 
turbofan engines, was published as a notice of proposed rulemaking 
(NPRM) in the Federal Register on January 24, 1992 (57 FR 2857). That 
action proposed to require the installation and periodic inspection of 
temperature indicators (temp tabs) installed on the No. 4 and 5 bearing 
compartment scavenge oil tube, performance of any necessary corrective 
action, and to require the installation of No. 4 and 5 bearing 
compartment hardware modifications for certain engines.
    On July 19, 1993, the FAA issued a Supplemental NPRM (58 FR 40083, 
July 27, 1993) that reopened the comment period, due to comments 
received and the determination that the bearing compartment hardware 
modifications do not adequately prevent internal leakage of thirteenth 
stage compressor discharge air into the No. 4 and 5 bearing 
compartment. That Supplemental NPRM proposed to require installation of 
improved temperature indicators to extend the compliance time for 
installation of temperature indicators, and to eliminate the 
requirement to perform No. 4 and 5 bearing compartment hardware 
modifications, in accordance with PW Alert Service Bulletin (ASB) No. 
5944, Revision 2, dated June 8, 1992, and ASB No. 6053, Revision 7, 
dated May 24, 1993.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.
    One commenter states that PW JT8D-Std series turbofan engines 
installed in Boeing 727 series aircraft should be exempt from the 
requirements of the AD based on the absence of uncontained engine 
failures over the last 16 years for those engines. The FAA concurs. The 
FAA has determined that the risk of uncontained engine failures on PW 
JT8D-Std series turbofan engines installed in Boeing 727 series 
aircraft has been reducing as newer model engines with improved 
containment capability have been accumulating an increasing percentage 
of fleet operating hours. Based on this determination, the FAA has 
concluded that a mandatory requirement to install the temperature 
indicators on these engines cannot be justified. Therefore, this final 
rule has been revised to remove from the applicability PW JT8D-Std 
series engines.
    One commenter states that the repetitive inspections and associated 
record keeping should be incorporated into the operators' FAA-approved 
maintenance program. The FAA does not concur. The FAA has determined 
that it is necessary to keep the repetitive inspections under the AD 
and separate from the routine-approved maintenance program to 
distinguish this activity as being critical to flight safety. In 
addition, this AD represents an interim program until installation of 
the HPT containment hardware in PW JT8D-200 series turbofan engines has 
been accomplished in accordance with AD 93-23-10.
    Two commenters state that the temp tab installation requirement 
should be extended beyond the current 90 days. The FAA does not concur. 
The FAA has provided ample notice of this requirement and extension of 
the installation grace period will increase the probability of a No. 4 
and 5 bearing compartment fire and possible shaft fracture. In 
addition, this 90 day grace period represents an increase from 65 days 
proposed in the NPRM.
    Two commenters state that the repetitive inspection interval should 
be changed from 65 hours time in service (TIS) to a longer interval or 
an interval based on calendar time. The FAA does not concur. Extension 
of this interval will increase the probability of a No. 4 and 5 
compartment fire to an unacceptable level. This interval represents a 
maximum limit, and shorter intervals can be selected to be consistent 
with calendar time maintenance schedules.
    One commenter states that temp tabs are unreliable and are subject 
to oil contamination and false indications, and that the program should 
be delayed until a new indicating method is developed. The FAA does not 
concur. The temp tab configuration specified in this rule and 
associated PW SB represent an improved version that incorporates a 
sealant which is applied over the indicator and prevents oil 
saturation. In addition, a procedure to determine if oil saturation has 
occurred is included in the associated PW SB. PW has developed a more 
costly mechanical pop-up indicator that is resistant to oil 
contamination. Introduction of this indicator is currently under 
evaluation and it may be available as an alternate means of compliance 
at a future date.
    Two commenters state that the cost impact does not take into 
account the expense of maintaining the temp tab indicators and the 
costs of troubleshooting false indications, and that, therefore, the 
total cost estimate for compliance with the AD should be increased to 
reflect these indirect costs. The FAA does not concur. The economic 
analysis reflects the direct cost of compliance with the requirements 
of the AD actions that the FAA has determined are necessary to correct 
an unsafe condition likely to exist on engines of this type design. The 
FAA has determined that adherence to the temp tab indicator 
installation instructions provided in PW SB No. 5944 will allow for 
reliable installation of the indicators. Once installed correctly, the 
temp tab indicators will provide warning of potentially catastrophic 
and costly abnormal engine conditions.
    One commenter states that the temp tab indicator part numbers 
should not be stated in the AD. The commenter maintains that the AD 
would then still be applicable for improved indicators with new part 
numbers when they are introduced. The FAA does not concur. A new 
revision to PW SB No. 5944 would be required to introduce new part 
numbers for new temp tab indicators, and the FAA may approve the new 
revision and installation of these new temp tab indicators as an 
alternative method of compliance.
    One commenter states that utilizing oil system condition monitoring 
and checks should allow for an increased temp tab indicator inspection 
interval. The FAA does not concur. The FAA has determined that the temp 
tab indicators are the most effective indicator of No. 4 and 5 bearing 
compartment overtemperature conditions. However, other oil system 
checks, such as oil consumption monitoring, breather pressure, and oil 
pressure, can be used to assist in the troubleshooting process and help 
identify bearing compartment overtemperature conditions.
    One commenter agrees with the rule as proposed.
    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the changes described 
previously. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.
    There are approximately 2,432 PW JT8D-200 series engines of the 
affected design in the worldwide fleet. The FAA estimates that 1,044 
engines installed on aircraft of U.S. registry will be affected by this 
AD, that it will take approximately 1.5 work hours per engine to 
accomplish the required actions, and that the average labor rate is $55 
per work hour. Based on these figures, the total cost impact of the AD 
on U.S. operators is estimated to be $85,883.
    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.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and (3) will not have a 
significant economic impact, positive or negative, on a substantial 
number of small entities under the criteria of the Regulatory 
Flexibility Act. A final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it 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 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

94-23-03 Pratt & Whitney: Amendment 39-9065. Docket 91-ANE-39.

    Applicability: Pratt & Whitney (PW) JT8D-209, -217, -217A, -
217C, and -219 turbofan engines that have not installed high 
pressure turbine (HPT) containment hardware in accordance with AD 
93-23-10. These engines are installed on but not limited to 
McDonnell Douglas MD-80 series and Boeing 727 series aircraft.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent fracture of the HPT shaft, which can result in 
uncontained release of engine fragments, engine fire, inflight 
engine shutdown, or possible aircraft damage, accomplish the 
following:
    (a) Install and inspect one or two temperature indicators, part 
number (P/N) 810486, or a single or double set of P/N 809129 and P/N 
809130 temperature indicators, on the No. 4 and 5 bearing 
compartment scavenge oil tube, as follows:
    (1) Install temperature indicators on the No. 4 and 5 bearing 
compartment scavenge oil tube in accordance with Section 2.A.(1) of 
the Accomplishment Instructions of PW Alert Service Bulletin (ASB) 
No. 5944, Revision 2, dated June 8, 1992, within 90 days after the 
effective date of this airworthiness directive (AD).
    (2) Visually inspect temperature indicators within 65 hours TIS 
of installation. Thereafter, inspect at intervals not to exceed 65 
hours TIS since last inspection.
    (3) If upon inspection, the color of any temperature indicator 
window(s) has turned completely black, perform troubleshooting and 
diagnostic testing and corrective action as required, in accordance 
with Section 2.A.(2)(c) and (d) or (f) and (g), as applicable, of 
the Accomplishment Instructions of PW ASB No. 5944, Revision 2, 
dated June 8, 1992. Prior to returning the engine to service, 
replace any temperature indicator that has turned black and inspect 
in accordance with paragraph (a)(2) and (a)(3) of this AD.
    (b) For aircraft installations utilizing one P/N 810486 
indicator or one set of P/N 809129 and 809130 indicators, and 
inspection reveals a missing indicator, inspect the remaining 
temperature indicator, if applicable, to determine if the indicator 
window has turned completely black. If the indicator window has 
turned completely black, perform troubleshooting and diagnostic 
testing, and corrective action as required, in accordance with 
paragraph (a)(3) of this AD. If the indicator window has not turned 
completely black or if there are no additional indicators installed, 
then install a new indicator in accordance with Section 2.A.(1) of 
the Accomplishment Instruction of PW ASB No. 5944, Revision No. 2, 
dated June 8, 1992, prior to return to service, and visually inspect 
the temperature indicator within 65 hours TIS since installation. 
Thereafter, inspect at intervals not to exceed 65 hours TIS since 
last inspection in accordance with paragraphs (a)(2) and (a)(3) of 
this AD.
    (c) For aircraft installations utilizing two P/N 810486 
indicators or two sets of P/N 809129 and 809130 indicators, and 
inspection reveals a missing indicator(s), inspect the remaining 
temperature indicator(s), if applicable, to determine if the 
indicator window has turned completely black. If the indicator 
window has turned completely black, perform troubleshooting and 
diagnostic testing, and corrective action as required, in accordance 
with paragraph (a)(3) of this AD. If the indicator window has not 
turned completely black, install a new indicator(s) in accordance 
with Section 2.A.(1) of the Accomplishment Instructions of PW ASB 
No. 5944, Revision 2, dated June 8, 1992, prior to return to 
service, and visually inspect the temperature indicator within 65 
hours TIS since installation. Thereafter, inspect at intervals not 
to exceed 65 hours TIS since last inspection in accordance with 
paragraphs (a)(2) and (a)(3) of this AD.
    (d) Report the data elements identified in Appendix E of the 
Accomplishment Instructions of PW ASB No. 5944, Revision 2, dated 
June 8, 1992, whenever an overtemperature condition is observed on 
any color temperature indicator which is the result of an internal 
engine problem only and not resulting from an external cause 
corrected by the published troubleshooting procedures. Data elements 
should be reported within 30 days of determining that the 
overtemperature condition is the result of an internal engine 
problem, to the Manager, Engine Certification Office, Engine and 
Propeller Directorate, Aircraft Certification Service, FAA, 12 New 
England Executive Park, Burlington, MA 01803-05299; fax (617) 238-
7199. The reporting requirements of this AD terminate six months 
from the effective date of the AD.
    (e) Information collection requirements contained in this 
regulation have been approved by the Office of Management and Budget 
under the provisions of the Paperwork Reduction Act of 1980 (Pub. L. 
96-511) and have been assigned OMB control number 2120-0056.
    (f) 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, Engine Certification Office.

    Note: Information concerning the existence of approved 
alternative methods of compliance with this airworthiness directive, 
if any, may be obtained from the Engine Certification Office.

    (g) Special flight permits may be issued in accordance with 
Secs. 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.
    (h) The installations and inspections shall be done in 
accordance with the following service bulletin:

------------------------------------------------------------------------
        Document No.            Pages     Revision          Date        
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PW ASB No. 5944.............       1-44          2  June 8, 1992.       
      Total pages: 44                                                   
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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, Technical 
Publications Department, M/S 132-30, 400 Main Street, East Hartford, 
CT 06108. 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.
    (i) This amendment becomes effective on January 31, 1995. Issued 
in Burlington, Massachusetts, on November 3, 1994.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 94-28374 Filed 12-1-94; 8:45 am]
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