[Federal Register Volume 63, Number 84 (Friday, May 1, 1998)]
[Proposed Rules]
[Pages 24138-24140]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-11559]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-ANE-59-AD]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney JT8D Series Turbofan 
Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the supersedure of an existing 
airworthiness directive (AD), applicable to certain Pratt & Whitney 
(PW) JT8D series turbofan engines, that currently requires initial and 
repetitive inspections of the No. 7 fuel nozzle and support assembly, 
replacement of the No. 7 fuel nozzle and support assembly with a more 
leak-resistant configuration, and replacement of aluminum oil pressure 
and scavenge tube fittings with steel fittings. In addition, the 
current AD requires replacing an additional aluminum oil scavenge line 
bolt with a steel bolt. This action would require initial and 
repetitive borescope inspections for loss of fuel nozzle nut torque and 
nozzle support wear, and replacement or modification of the fuel 
nozzles at the next accessibility of the diffuser build group as 
terminating action to the inspections. This proposal is prompted by 
reports of loss of fuel nozzle nut torque and nozzle support wear. The 
actions specified by the proposed AD are intended to prevent loss of 
fuel nozzle nut torque and nozzle support wear, which could result in a 
fuel leak and possible engine fire.

DATES: Comments must be received by June 30, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), New England Region, Office of the Regional 
Counsel, Attention: Rules Docket No. 97-ANE-59-AD, 12 New England 
Executive Park, Burlington, MA 01803-5299. Comments may also be sent 
via the Internet using the following address: ``9-ad-
[email protected]''. Comments sent via the Internet must contain 
the docket number in the subject line. Comments may be inspected at 
this location between 8:00 a.m. and 4:30 p.m., Monday through Friday, 
except Federal holidays.
    The service information referenced in the proposed rule may be 
obtained from Pratt & Whitney, 400 Main St., East Hartford, CT 06108; 
telephone (860) 565-6600, fax (860) 565-4503. This information may be 
examined at the FAA, New England Region, Office of the Regional 
Counsel, 12 New England Executive Park, Burlington, MA.

FOR FURTHER INFORMATION CONTACT: Christopher Spinney, Aerospace 
Engineer, Engine Certification Office, FAA, Engine and Propeller 
Directorate, telephone (781) 238-7175, fax (781) 238-7199.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed rule by submitting such written data, views, or arguments as 
they may desire. Communications should identify the Rules Docket number 
and be submitted in triplicate to the address specified above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this notice may be changed in 
light of the comments received.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule. All 
comments submitted will be available, both before and after the closing 
date for comments, in the Rules Docket for examination by interested 
persons. A report summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 97-ANE-59-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, New England Region, Office of the Regional Counsel, 
Attention: Rules Docket No. 97-ANE-59-AD, 12 New England Executive 
Park, Burlington, MA 01803-5299.

Discussion

    On January 24, 1995, the Federal Aviation Administration (FAA) 
issued airworthiness directive AD 95-02-16, Amendment 39-9135 (60 FR 
6654, February 3, 1995), applicable to Pratt & Whitney (PW) JT8D series 
turbofan engines, to require inspection of the No. 7 fuel nozzle and 
support assembly for evidence of fuel leakage and burning until 
replacement of the No. 7 fuel nozzle and support assembly with an 
improved sealing configuration. That AD also requires replacement of 
the aluminum oil tube fittings with steel fittings. In addition, that 
AD requires replacing an additional aluminum oil scavenge line bolt 
with a steel bolt. That action was prompted by reports of two 
uncontained engine fires due to fuel leakage from the No. 7 fuel nozzle 
and

[[Page 24139]]

support assembly, ignition of that fuel, melting of aluminum oil 
pressure and scavenge tube fittings that are in the proximity of the 
No. 7 nozzle, and augmentation of that fire with the liberated oil. 
That condition, if not corrected, could result in fuel leakage from the 
No. 7 fuel nozzle and support assembly, ignition of that leaking fuel, 
and liberation of oil from melted oil line fittings, which can result 
in an uncontained engine fire and damage to the aircraft.
    Since the issuance of that AD, the FAA has received reports of loss 
of fuel nozzle nut torque and nozzle support wear. AD 95-02-16 mandated 
welding of the No. 7 fuel nozzles to the fuel nozzle support to prevent 
secondary fuel leakage and replacement of oil scavenge lines to a more 
fire resistant stainless steel. Field experience has shown that the 
welding of the fuel nozzle to the fuel nozzle support can cause a loss 
of torque on the fuel nozzle nut. The loss of torque on the fuel nozzle 
nut results in rotation of the nut and air scoop assembly and 
subsequent contact between the airscoop and the nozzle support fairing, 
resulting in wear through the fairing and nozzle support and eventually 
a secondary fuel leak. The loss of nut torque has also been reported to 
cause thread wear, which in some cases has resulted in liberation of 
the nozzle from the support after it has been removed from the engine.
    The FAA has reviewed and approved the technical contents of PW 
Alert Service Bulletin (ASB) No. A6310, dated October 13, 1997, that 
describes procedures for inspections for loss of fuel nozzle nut torque 
and nozzle support wear, and ASB No. A6311, dated October 14, 1997, 
that describes procedures for replacement or modification of fuel 
nozzles to an improved design.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, the 
proposed AD would supersede AD 95-02-16 to require initial and 
repetitive inspections for loss of fuel nozzle nut torque and nozzle 
support wear, and replacement or modification of the fuel nozzles at 
the next accessibility of the diffuser build group as terminating 
action to the inspections. The calendar end-date was determined based 
upon risk analysis and parts availability.
    There are approximately 13,902 engines of the affected design in 
the worldwide fleet. The FAA estimates that 7,100 engines installed on 
aircraft of U.S. registry would be affected by this proposed AD, that 
it would take approximately 0.3 work hours per engine to accomplish the 
proposed inspections, and 9.2 hours to perform the proposed 
modifications or replacement, and that the average labor rate is $60 
per work hour. Required parts would cost approximately $12,620 per 
engine to replace the nozzle and $1,500 to modify existing nozzles. The 
FAA estimates that 10% of the nozzles will have to be replaced. Based 
on these figures, the total cost impact of the proposed AD on U.S. 
operators is estimated to be $18,950,000 .
    The regulations proposed herein would 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 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this proposed 
regulation (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) if promulgated, 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 copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting the Rules 
Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
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. 106(g), 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by removing amendment 9135 (60 FR 6654, 
February 3, 1995) and by adding a new airworthiness directive to read 
as follows:

Pratt & Whitney: Docket No. 97-ANE-59-AD. Supersedes AD 95-02-16, 
Amendment 39-9135.

    Applicability: Pratt & Whitney (PW) Model JT8D-209, -217, -217A, 
-217C, -219, -1, -1A, -1B, -7, -7A, -7B, -9, -9A, -11, -15, -15A, -
17, -17A, -17R, and -17AR turbofan engines incorporating the 
modifications described in PW Service Bulletin (SB) No. 5650, dated 
January 17, 1986, Alert Service Bulletin (ASB) No. A6169, Revision 
4, dated June 5, 1996, or earlier revisions, or SB 6240, dated 
January 20, 1996, and any PW Model JT8D engine with low emissions 
fuel nozzle and support assemblies, Part Numbers 775485, 809137-01, 
802965, 5004308-02, 5004308-032, 814358, 5004308-042 or 815658-01 
installed. These engines are installed on but not limited to Boeing 
727 and 737 series, and McDonnell Douglas DC-9 and MD-80 series 
aircraft.

    Note 1: This airworthiness directive (AD) applies to each engine 
identified in the preceding applicability provision, regardless of 
whether it has been modified, altered, or repaired in the area 
subject to the requirements of this AD. For engines that have been 
modified, altered, or repaired so that the performance of the 
requirements of this AD is affected, the owner/operator must request 
approval for an alternative method of compliance in accordance with 
paragraph (f) of this AD. The request should include an assessment 
of the effect of the modification, alteration, or repair on the 
unsafe condition addressed by this AD; and, if the unsafe condition 
has not been eliminated, the request should include specific 
proposed actions to address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent loss of fuel nozzle nut torque and nozzle support 
wear, which could result in a fuel leak and possible engine fire, 
accomplish the following:
    (a) For engines that have not incorporated modifications to the 
No. 7 fuel nozzle and support assembly in accordance with PW ASB No. 
A6169, Revision 4, dated January 20, 1996, or earlier revisions, or 
PW SB No. 6240, dated January 20, 1996, as of the effective date of 
this AD; or for engines that have not incorporated the oil scavenge 
tube and fitting modifications in accordance with ASB No. A6170, 
dated October 20, 1994, as of the effective date of this AD, 
accomplish the following:
    (1) Inspect No. 7 fuel nozzle and support assemblies in 
accordance with PW ASB No. A6153, Revision 1, dated June 8, 1994, as 
follows:
    (i) For engines that have accumulated 3,200 hours or more time 
in service (TIS) since last fuel nozzle and support assembly 
overhaul and have not received an initial inspection for fuel 
leakage, perform an initial inspection for fuel leakage before 
further flight.
    (ii) For engines that have accumulated less than 3,200 hours TIS 
since last fuel nozzle and support assembly overhaul and have not 
received an initial inspection for fuel leakage, perform an initial 
inspection for fuel leakage

[[Page 24140]]

prior to accumulating 3,200 hours TIS since last fuel nozzle and 
support assembly overhaul.
    (iii) Thereafter, inspect for fuel leakage in accordance with PW 
ASB A6153, Revision 1, dated June 8, 1994, at intervals not to 
exceed 700 hours TIS since last inspection.
    (iv) Remove from service No. 7 fuel nozzle and support 
assemblies that exhibit evidence of fuel leakage as described in PW 
ASB No. A6153, Revision 1, dated June 8, 1994, and replace with the 
improved sealing configuration nozzle in accordance with paragraph 
(a)(2)(i) of this AD, as follows:
    (A) Within 25 hours TIS, or 25 cycles in service (CIS), 
whichever occurs first, after the inspection performed in paragraph 
(a)(1) for aircraft with only one engine exhibiting No. 7 fuel 
nozzle and support assembly leakage.
    (B) Prior to further flight, on aircraft with two or more 
engines exhibiting No. 7 fuel nozzle and support assembly leakage, 
remove and replace at least all but one of the leaking No. 7 fuel 
nozzle and support assemblies. If not replacing all leaking No. 7 
fuel nozzle and support assemblies, the remaining No. 7 fuel nozzle 
and support assembly that exhibits leakage shall be removed and 
replaced in accordance with paragraph (a)(1)(iv)(A) of this AD.
    (2) At the next accessibility of the diffuser build group after 
the effective date of the AD, but no later than July 31, 1999, 
accomplish the following:
    (i) Replace the No. 7 fuel nozzle and support assembly in 
accordance with paragraph 1.B.(3) of the Accomplishment Instructions 
of PW ASB No. A6311, dated October 14, 1997.
    (ii) Replace the aluminum pressure and scavenge oil tube 
fittings with steel fittings in accordance with PW ASB No. A6170, 
Revision 2, dated October 20, 1994.
    (iii) Replacement of the following oil tubes with corresponding 
oil tubes that incorporate steel fittings constitutes compliance 
with paragraph (b)(2) of this AD:
    (A) Outer internal No. 4 and 5 bearing pressure tube assembly 
for PW JT8D-200 series engines.
    (B) Outer internal main bearing pressure tube assembly for PW 
JT8D-200 series engines.
    (C) Main bearing pressure manifold assembly for PW JT8D-200 
series engines.
    (D) Front No. 4 1/2 and 6 bearing pressure tube assembly for 
JT8D-200 series engines.
    (E) No. 4 bearing oil scavenge tube assembly for all other JT8D 
engines.
    (F) No. 4 bearing oil pressure tube assembly for all other JT8D 
engines.
    (G) Main bearing pressure manifold assembly for all other JT8D 
engines.
    (3) Incorporation of the hardware required by paragraph 
(a)(2)(i) of this AD constitutes terminating action for the 
inspections required by paragraphs (a)(1) of this AD.
    (b) For engines that have incorporated modifications of the No. 
7 fuel nozzle and support assembly in accordance with PW ASB No. 
A6169, Revision 4, dated June 5, 1996, or earlier revisions, and 
have not incorporated the replacement of the No. 7 fuel nozzle and 
support assembly with a fuel nozzle and support assembly with tack 
welded lock tabs in accordance with PW SB No. 6240, dated January 
12, 1996, accomplish the following.
    (1) Borescope inspect, remove, and replace fuel nozzle and 
support assemblies for nut rotation in accordance with methods, 
intervals and inspection criteria specified in PW ASB No. 6310, 
dated October 13, 1997.
    (2) At the next accessibility of the diffuser build group after 
the effective date of the AD, but no later than [Insert 5 years 
after the effective date of the AD] , replace the No. 7 fuel nozzle 
and support assembly with a welded air nozzle assembly in accordance 
with paragraph 1.B.(1), 1.B.(2) and 1.B.(3) of the Accomplishment 
Instructions of PW ASB No. A6311, dated October 14, 1997.
    (3) Accomplishment of paragraph (b)(2) of this AD is terminating 
action to the inspections of paragraph (b)(1) of this AD.
    (c) For engines that have incorporated the replacement of the 
No. 7 fuel nozzle and support assembly with a fuel nozzle and 
support assembly with tack welded lock tabs in accordance with PW SB 
No. 6240, dated January 12, 1996, at the next accessibility of the 
diffuser build group after the effective date of the AD, but no 
later than [insert 5 years after the effective date of the AD], 
replace the No. 7 fuel nozzle and support assembly with a welded air 
nozzle assembly in accordance with paragraph 1.A.(1), 1.A.(2) and 
1.A.(3) of the Accomplishment Instructions of PW ASB No. A6311, 
dated October 14, 1997.
    (d) For the purpose of this AD, accessibility of the diffuser 
build group is defined as engine maintenance that entails flange 
separation of the diffuser case from the combustion chamber outer 
case.
    (e) For the purpose of this AD, fuel nozzle and support assembly 
overhaul is defined as disassembly of the fuel nozzle from the 
support assembly that entails removal of the fuel nozzle nut.
    (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. 
Operators shall submit their requests through an appropriate FAA 
Principal Maintenance Inspector, who may add comments and then send 
it to the Manager, Engine Certification Office.

    Note 2: 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 
sections 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.

    Issued in Burlington, Massachusetts, on April 23, 1998.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 98-11559 Filed 4-30-98; 8:45 am]
BILLING CODE 4910-13-P