[Federal Register: October 17, 2005 (Volume 70, Number 199)]
[Rules and Regulations]
[Page 60211-60214]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr17oc05-4]
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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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