Airworthiness Directives; Pratt & Whitney JT8D-200 Series Turbofan Engines

[Federal Register Volume 70, Number 199 (Monday, October 17, 2005)]
[Rules and Regulations]
[Pages 60211-60214]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-20501]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96-ANE-35-AD; Amendment 39-14339; AD 2005-21-01]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney JT8D-200 Series 
Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD) that applies to Pratt & Whitney (PW) JT8D-200 series turbofan 
engines. That AD currently requires installing and periodically 
inspecting individual or sets of certain part number (P/N) temperature 
indicators on the No. 4 and 5 bearing compartment scavenge oil tube and 
performance of any necessary corrective action. This AD requires 
installing and periodically inspecting two temperature indicators on 
all PW JT8D-200 series turbofan engines, including those incorporating 
high pressure turbine (HPT) containment hardware. This AD results from 
five uncontained HPT shaft failures. We are issuing this AD to prevent 
oil fires and the resulting fracture of the HPT shaft which can result 
in uncontained release of engine fragments; engine fire; in-flight 
engine shutdown; and possible airplane damage.

DATES: This AD becomes effective November 21, 2005. The Director of the 
Federal Register approved the incorporation by reference of certain 
publications listed in the regulations as of November 21, 2005.

ADDRESSES: You can get the service information identified in this AD 
from Pratt & Whitney, 400 Main St., East Hartford, CT 06108; telephone 
(860) 565-7700, fax (860) 565-1605.
    You may examine the AD docket at the FAA, New England Region, 
Office of the Regional Counsel, 12 New England Executive Park, 
Burlington, MA. You may examine the service information, at the FAA, 
New England Region, Office of the Regional Counsel, 12 New England 
Executive Park, Burlington, MA.

FOR FURTHER INFORMATION CONTACT: Keith Lardie, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803-5299; telephone (781) 
238-7189, fax (781) 238-7199.

SUPPLEMENTARY INFORMATION: The FAA proposed to amend 14 CFR part 39 by 
superseding AD 97-19-13, Amendment 39-10134 (62 FR 49135, September 19, 
1997). The proposed AD applies to PW JT8D-200 series turbofan engines. 
We published the proposed AD in the Federal Register on September 29, 
2004 (69 FR 58099). That action proposed to require installing and 
periodically inspecting two P/N 810486 temperature indicators on all PW 
JT8D-200 series turbofan engines, including those incorporating HPT 
containment hardware. Thirteen HPT shaft fractures resulted in five 
uncontained HPT shaft failures. The HPT shafts fractured through the 
No. 4\1/2\ oil return holes due to oil fires within the No. 4 and 5 
bearing compartment.

Examining the AD Docket

    You may examine the AD Docket (including any comments and service 
information), by appointment, between 8 a.m. and 4:30 p.m., Monday 
through Friday, except Federal holidays. See ADDRESSES for the 
location.

Comments

    We provided the public the opportunity to participate in the 
development of this AD. We have considered the comments received.

Concerns Over Considering the Engine Unserviceable

    Four commenters state that an engine should not be considered 
unserviceable and the engine removed from service if both temperature 
indicators are missing. The commenters state that we should allow 
installing new temperature indicators followed by a ground diagnostic 
test before further flight.
    One of those commenters states that considering the engine 
unserviceable imposes an undue hardship on operators. If one of the 
indicators is missing, PW Alert Service Bulletin (ASB) No. JT8D A5944 
requires that the engine be tested using specific instructions to 
determine its serviceability and the engine be dispositioned 
accordingly. The theory used for one indicator missing is that the 
serviceability of the engine is now questionable and the engine must be 
proven serviceable before it can be returned to service. The commenter 
further states that any time engine serviceability is in question, it 
must be proven and cannot be assumed. Requiring operators to remove the 
engine from service, simply because both of the indicators are missing, 
forces operators into a position without recourse. The commenter 
further states that this is the same condition already covered when one 
indicator is missing. The procedure to determine serviceability for 
both indicators missing should follow the procedure for one indicator 
missing but with minor changes.
    We agree. We have changed the compliance section of the AD to allow 
a ground diagnostic test before further flight if both temperature 
indicators are missing.

AD Instructions Not Clear

    One commenter states that the AD instructions for a missing 
indicator are not clear. The instructions for one indicator missing 
assume that the missing indicator has a red window that has turned 
black. The commenter asks if the yellow window of the missing indicator 
should be assumed to be normal color or black. The condition of the 
remaining indicator would make a difference as to whether a diagnostic

[[Page 60212]]

test may be run or if the engine must be removed.
    We agree. PW supplied better instructions in Revision 5 to PW ASB 
No. JT8D A5944, which we incorporated by reference. For troubleshooting 
purposes, any missing temperature indicator is assumed to have the same 
indication as the remaining temperature indicator. Therefore, the 
results of the visual inspection of the one remaining temperature 
indicator should be doubled. This should minimize operator impact due 
to false indications.

Follow-Up Inspection Requirements Too Restrictive

    One commenter states the follow-up inspection requirements for 
certain conditions are too restrictive. In the cases where the proposed 
requirements state to check the temperature indicators following every 
flight should be eased to require a check of the temperature indicators 
once a day. The commenter feels that the economic burden of checking 
the indicators following every flight outweighs the risk.
    We disagree. An indicator with a black window probably is a sign of 
an impending problem with the engine. The typical progression for the 
indicator windows to change from normal tan color to black is as 
follows: One yellow, two yellow, or two yellow with one or two red 
windows. Any combination other than this progression is not expected 
and would signal that the reliability of the engine is in question. For 
example, if both red windows, which are rated about 50 degrees 
Fahrenheit hotter than the yellow windows, have turned black, but none 
of the yellow windows have turned black, a problem may exist with the 
indicator installation, or hot air might be impinging from a stuck 
carbon seal. A ground diagnostic test cannot accurately reproduce the 
symptom of a stuck carbon seal. In one case following an indication of 
one yellow window and one red window turned black, a shaft fracture 
occurred only two cycles after a visual inspection, despite engine 
diagnostic test and other troubleshooting. This type of failure will 
occur quickly, which is why intensive inspections are required.

Use of Dual-Window Temperature Indicators

    One commenter agrees with the proposed AD that dual-window 
temperature indicators should be used and sealed to minimize false 
indications. The commenter further states that in a situation where hot 
air impingement or indicator contamination is determined to cause a 
false indication, a ground diagnostic test should be allowed to return 
the engine to service.
    We partially agree. In most cases, operators will be unable to show 
that the source of black windows seen during a visual inspection is 
indicator contamination or hot air impingement. Operators must follow 
all of the manufacturer's instructions for installation of temperature 
indicators to minimize false indications.

Troubleshooting On-Wing

    Two commenters disagree with the last two dispositions in the table 
for Visual Inspection of Dual Window Indications, in Alert Service 
Bulletin (ASB) No. A5944, Revision 4, dated April 8, 2004. Those 
dispositions state to remove the engine, whereas the other dispositions 
in the table allow for troubleshooting the engine on-wing. The 
commenter states that troubleshooting for false indications should be 
also allowed for these two dispositions. Hot air impingement could be 
more likely due to close proximity to sources of contamination and 
would lead to false indications. The commenter did not supply any data 
or field experience to support the concern.
    We disagree. The new mandatory sealing instructions for the 
temperature indicators will prevent most false indications. An 
indicator combination of two yellow windows turned black with at least 
one red window turned black is not more likely a result of 
contamination due to hot air impingement than any other situation 
involving indicators showing at least one black window. If one properly 
installs the temperature indicators, the last two dispositions 
involving temperature indicators with black windows probably are a sign 
of a significant engine problem. Since uncontained HPT shaft fractures 
continue to occur, a more conservative approach is necessary to prevent 
their future occurrence.

Use of an Immersion Thermocouple

    One commenter feels that an immersion thermocouple should be 
allowed for all situations in which a window of a temperature indicator 
has turned black.
    We disagree. An immersion thermocouple provides a more accurate 
reading of temperature. However, an immersion thermocouple can only be 
used during ground diagnostic tests and may not help detect in-flight 
issues that cannot be reproduced on the ground, such as a stuck carbon 
seal. We did not change the AD.

Alert Service Bulletin Is Too Precise

    One commenter states that paragraph 1.B of the Accomplishment 
Instructions of PW ASB No. A5944, Revision 4, dated April 8, 2004, is 
too precise for otherwise inaccurate temperature indicator 
measurements. The commenter states that the ASB requires diagnostic 
tests in intervals from before further flight to 10, 20, or 25 hours or 
cycles.
    We disagree. We used past failure event field data to establish 
diagnostic testing intervals. Temperature indicators, although they do 
not provide an absolute temperature indication, are an effective method 
of determining the health of the scavenge system. Requiring a full 
ground diagnostic test every 65 hours would be an unnecessary economic 
burden for the operators. Therefore, for different indicator 
conditions, depending on the severity of the indications, different 
follow-on testing requirements are appropriate.

Concerns With ASB Instructions

    One commenter states that the ASB instructions for manufacture of 
the thermocouple are inaccurate and incomplete in some areas, and too 
detailed in other areas. The instructions specify too long a 
thermocouple and provide no sealing instructions to prevent oil from 
leaking past the thermocouple. The instructions also are so detailed 
for drilling the chip detector, that the operator is left few other 
options. The commenter further states that PW should not mandate the 
brand of thermocouple. The commenter feels that operators should be 
given the intent of the design specifications for installing a 
thermocouple, and be given flexibility to choose their own installation 
based on these requirements.
    We agree. PW has revised the instructions for the thermocouple, 
which are in ASB No. JT8D A5944, Revision 5, dated October 3, 2005.

Equivalent Parts

    One commenter states that the use of equivalent parts to 
temperature indicator, PW P/N 810486, should be permitted. A parts 
manufacturer approval (PMA)-equivalent, P/N 3641, is available. The 
commenter also requests that the AD wording be changed so that it does 
not imply that the OEM is the only supplier of an approved temperature 
indicator for this AD.
    We partially agree. PMA parts are acceptable. But presently only 
one, PMA P/N 3641, is available as a substitute for PW P/N 810486. We 
changed the AD to include this PMA-equivalent.

[[Page 60213]]

Other Changes to the Compliance Section for Clarification

    Several commenters suggest that the Compliance section is unclear. 
We agree that it could be clearer. We changed the Compliance section to 
clarify the procedures.

Conclusion

    We have carefully reviewed the available data, including the 
comments received, and determined that air safety and the public 
interest require adopting the AD with the changes described previously. 
We have determined that these changes will neither increase the 
economic burden on any operator nor increase the scope of the AD.

Costs of Compliance

    There are about 2,345 PW JT8D-200 series turbofan engines of the 
affected design in the worldwide fleet. We estimate that 1,143 engines 
installed on airplanes of U.S. registry would be affected by this AD. 
We also estimate that it would take about 1 work hour per engine to 
perform the actions, and that the average labor rate is $65 per work 
hour. Required parts would cost about $37 per engine. Based on these 
figures, we estimate the total cost of the AD to U.S. operators to be 
$116,586.

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 AD will not have federalism 
implications under Executive Order 13132. This AD will 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 this AD:
    (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.
    We prepared a summary of the costs to comply with this AD and 
placed it in the AD Docket. You may get a copy of this summary by 
sending a request to us at the address listed under ADDRESSES. Include 
``AD Docket No. 96-ANE-35-AD'' in your request.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the Federal Aviation Administration amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The FAA amends Sec.  39.13 by removing Amendment 39-10134 (62 FR 
49135, September 19, 1997) and by adding the following new 
airworthiness directive:

2005-21-01 Pratt & Whitney: Amendment 39-14339. Docket No. 96-ANE-
35-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective November 
21, 2005.

Affected ADs

    (b) This AD supersedes AD 97-19-13, Amendment 39-10134.

Applicability

    (c) This AD applies to Pratt & Whitney (PW) JT8D-200 series 
turbofan engines. These engines are installed on, but not limited 
to, McDonnell Douglas MD-80 series and Boeing 727 series airplanes.

Unsafe Condition

    (d) This AD results from five uncontained high pressure turbine 
(HPT) shaft failures out of thirteen HPT shaft fractures due to oil 
fires in the No. 4 and 5 bearing compartments. We are issuing this 
AD to prevent oil fires; fracture of the HPT shaft which can result 
in uncontained release of engine fragments; engine fire; in-flight 
engine shutdown; and possible airplane damage.

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.

Installation of the Dual-Window Temperature Indicators

    (f) Install two dual-window temperature indicators on the No. 4 
bearing compartment scavenge oil tubes of PW JT8D-200 series 
turbofan engines within 90 days after the effective date of this AD.
    (1) Use paragraph 1.A. of the Accomplishment Instructions of PW 
Alert Service Bulletin (ASB) No. JT8D A5944, Revision 5, dated 
October 3, 2005, to install the temperature indicators.
    (2) The use of part manufacturer approval (PMA)-equivalent 
temperature indicators, P/N 3641, made by Telatemp Corporation, is 
acceptable.

Initial Visual Inspection of the Dual-Window Temperature Indicators

    (g) Perform initial visual inspection of the dual-window 
temperature indicators installed in paragraph (f) of this AD within 
65 hours time-in-service (TIS) since installation.
    (h) If the color of any temperature indicator window has turned 
black, perform troubleshooting, diagnostic testing, and corrective 
action as required, using paragraph 1.B. of the Accomplishment 
Instructions of PW ASB No. JT8D A5944, Revision 5, dated October 3, 
2005.
    (i) If any temperature indicators are missing:
    (1) If one temperature indicator is missing, inspect the 
remaining temperature indicator and perform troubleshooting, 
diagnostic testing, and corrective action as required, using 
Paragraph B.2. of the Accomplishment Instructions of PW ASB No. JT8D 
A5944, Revision 5, dated October 3, 2005.
    (2) If both temperature indicators are missing:
    (i) Perform troubleshooting, diagnostic testing, and corrective 
action as required, using Figure 2 of the Accomplishment 
Instructions of PW ASB No. JT8D A5944, Revision 5, dated October 3, 
2005.
    (ii) Perform both engine diagnostic tests as specified in Figure 
3 and Figure 4 of the Accomplishment Instructions of PW ASB No. JT8D 
5944, Revision 5, dated October 3, 2005.
    (iii) If the engine fails the diagnostic tests for red 
indicators, do not perform the test for yellow indicators. Remove 
the engine from service.
    (3) If the test results show an oil overtemperature condition, 
remove the engine from service.
    (4) If the test results show no oil overtemperature condition:
    (i) Replace any temperature indicator that has turned black as 
specified in paragraph (h) of this AD; and
    (ii) Replace any temperature indicator that is missing as 
specified in paragraph (i) of this AD; and
    (iii) Return the engine to service, and inspect as specified in 
paragraph (g) of this AD.

[[Page 60214]]

Repetitive Visual Inspection of the Dual-Window Temperature Indicators

    (j) Perform repetitive visual inspections of the dual-window 
temperature indicators installed in paragraph (f) of this AD within 
65 hours TIS since-last-inspection. Use paragraph (h) of this AD to 
inspect the temperature indicators.

Requirements for Thermocouple Installation for On-Wing Diagnostic Test

    (k) The requirements for thermocouple installation are listed in 
Appendix B of PW ASB No. JT8D A5944, Revision 5, dated October 3, 
2005.

On-Wing Diagnostic Test Information

    (l) To perform the on-wing diagnostics test, use Appendix C of 
PW ASB No. JT8D A5944, Revision 5, dated October 3, 2005.

Material Incorporated by Reference

    (m) You must use Pratt & Whitney Alert Service Bulletin No. JT8D 
A5944, Revision 5, dated October 3, 2005, to perform the inspections 
and tests required by this AD. The Director of the Federal Register 
approved the incorporation by reference of this service bulletin in 
accordance with 5 U.S.C. 552(a) and 1 CFR part 51. You can get a 
copy from Pratt & Whitney, 400 Main St., East Hartford, CT 06108; 
telephone (860) 565-7700, fax (860) 565-1605. You can review copies 
at the FAA, New England Region, Office of the Regional Counsel, 12 
New England Executive Park, Burlington, MA; or at the National 
Archives and Records Administration (NARA). For information on the 
availability of this material at NARA, call 202-741-6030, or go to: 
http://www.archives.gov/federal-register/cfr/ibr-locations.html.

Related Information

    (n) None.

    Issued in Burlington, Massachusetts, on October 3, 2005.
Francis A. Favara,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 05-20501 Filed 10-14-05; 8:45 am]
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