[Federal Register Volume 61, Number 21 (Wednesday, January 31, 1996)]
[Proposed Rules]
[Pages 3340-3341]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-1876]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 95-NM-154-AD]
Airworthiness Directives; Boeing Model 767 Series Airplanes
Equipped with Pratt & Whitney Model JT9D-7R4 Engines
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes the adoption of a new airworthiness
directive (AD) that is applicable to certain Boeing Model 767 series
airplanes. This proposal would require a visual inspection to verify
proper clearance between the number 18 fuel nozzle secondary transfer
fuel tube and the pylon drain tube of the engine, and various follow-on
actions. The proposal would also require installation of clamps and
associated fasteners between the environmental control system (ECS)
controller tube and the pylon drain tube. This proposal is prompted by
reports of chafing of the number 18 fuel nozzle secondary transfer fuel
tube of the engine due to an improperly installed or loose pylon drain
tube. The actions specified by the proposed AD are intended to prevent
such chafing, which could lead to subsequent fuel leakage and a
possible engine fire.
DATES: Comments must be received by March 26, 1996.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 95-NM-154-AD, 1601 Lind Avenue, SW.,
Renton, Washington 98055-4056. Comments may be inspected at this
location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except
Federal holidays.
The service information referenced in the proposed rule may be
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle,
Washington 98124-2207. This information may be examined at the FAA,
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton,
Washington.
FOR FURTHER INFORMATION CONTACT: Monica Gandara Merritt, Aerospace
Engineer, Propulsion Branch, ANM-140S, FAA, Seattle Aircraft
Certification Office, 1601 Lind Avenue, SW., Renton, Washington;
telephone (206) 227-2683; fax (206) 227-1181.
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 shall 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 95-NM-154-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, Transport Airplane Directorate, ANM-103, Attention: Rules
Docket No. 95-NM-154-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
The FAA has received reports of chafing of the number 18 fuel
nozzle secondary transfer fuel tube, which resulted in excessive fuel
leakage on one airplane and an engine fire on another airplane. These
incidents occurred on Boeing Model 767 series airplanes equipped with
Pratt & Whitney Model JT9D-7R4 engines. In the engine fire incident,
investigation revealed that the cause of the chafing was attributed to
the installation of the wrong engine fuel manifold, which did not
provide for adequate clearance for the fuel tube. In the fuel leakage
incident, investigation revealed that the cause of the chafing was
attributed to an improperly installed or loose pylon drain tube, which
contacted the fuel transfer tube and subsequently chafed against it.
Chafing of the number 18 fuel nozzle secondary transfer fuel tube of
the engine, if not detected and corrected in a timely manner, could
lead to fuel leakage and, consequently, a possible engine fire.
The FAA has reviewed and approved Boeing Alert Service Bulletin
767-71A0082, dated July 6, 1995, which describes procedures for
installation of clamps and associated fasteners between the
environmental control system (ECS) and the pylon drain tube. The
installation will ensure that proper clearance between the engine fuel
manifold and the pylon drain line is maintained.
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 require installation of clamps and associated
fasteners between the ECS controller tube and the pylon drain tube. The
actions would be required to be accomplished in accordance with the
alert service bulletin described previously.
Additionally, the proposed AD would require a visual inspection to
verify that proper clearance (0.5 inch) exists between the number 18
fuel nozzle secondary transfer fuel tube and the pylon drain tube of
the engine; and follow-on actions (i.e., visual inspection for damage,
relocation of the pylon tube, and repair or replacement of a damaged
tube). The FAA has determined that accomplishing only the installation
of clamps and associated fasteners, as described previously, would not
eliminate any damage from chafing that may currently exist on the fuel
tube. The FAA has determined that any existing chafing damage must be
identified and corrected.
There are approximately 93 Model 767 series airplanes equipped with
Pratt & Whitney Model JT9D-7R4 engines of the affected design in the
worldwide fleet. The FAA estimates that 30 airplanes of U.S. registry
would be affected by this proposed AD, that it would take approximately
4 work hours per airplane to accomplish the proposed actions, and that
the average labor rate is $60 per work hour. Required parts
[[Page 3341]]
would cost approximately $31 per airplane. Based on these figures, the
cost impact of the proposed AD on U.S. operators is estimated to be
$8,130, or $271 per airplane.
The cost impact figure discussed above is based on assumptions that
no operator has yet accomplished any of the proposed requirements of
this AD action, and that no operator would accomplish those actions in
the future if this AD were not adopted.
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 USC 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
Boeing: Docket 95-NM-154-AD.
Applicability: Model 767 series airplanes having line position 1
through 329 inclusive; equipped with Pratt & Whitney Model JT9D-7R4
engines; certificated in any category.
Note 1: This AD applies to each airplane 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 airplanes that have been modified,
altered, or repaired so that the performance of the requirements of
this AD is affected, the owner/operator must use the authority
provided in paragraph (b) of this AD to request approval from the
FAA. This approval may address either no action, if the current
configuration eliminates the unsafe condition; or different actions
necessary to address the unsafe condition described in this AD. Such
a request should include an assessment of the effect of the changed
configuration on the unsafe condition addressed by this AD. In no
case does the presence of any modification, alteration, or repair
remove any airplane from the applicability of this AD.
Compliance: Required as indicated, unless accomplished
previously.
To prevent chafing of the number 18 fuel nozzle secondary
transfer fuel tube of the engine, and subsequent fuel leakage and
possible engine fire, accomplish the following:
(a) Within 6 months after the effective date of this AD, perform
a visual inspection to verify proper clearance (0.5 inch) between
the number 18 fuel nozzle secondary transfer fuel tube and the pylon
drain tube of the engine.
(1) If the clearance is equal to or greater than 0.5 inch, prior
to further flight, install clamps and associated fasteners between
the environmental control system (ECS) and the pylon drain tube, in
accordance with Boeing Alert Service Bulletin 767-71A0082, dated
July 6, 1995.
(2) If the clearance is less than 0.5 inch, prior to further
flight, perform a visual inspection to detect damage of the number
18 fuel nozzle secondary transfer fuel tube and the pylon drain
tube.
(i) If no damage is detected, or if any damage to the number 18
fuel nozzle secondary transfer tube is less than or equal to 0.002
inch deep and if any damage to the drain tube is less than or equal
to 0.010 inch deep, prior to further flight, relocate the pylon
drain tube to meet the 0.5 inch specification. After accomplishing
the relocation, prior to further flight, install the clamps and
associated fasteners between the ECS and the pylon drain tube, in
accordance with Boeing Alert Service Bulletin 767-71A0082, dated
July 6, 1995.
(ii) If any damage to the number 18 fuel tube is greater than
0.002 inch deep, or if any damage to the drain tube is greater than
0.010 inch deep, prior to further flight, repair or replace the
damaged tube, in accordance with Section 28-00-10 of the Overhaul
Manual. After accomplishing the repair or replacement, prior to
further flight, install the clamps and associated fasteners between
the ECS and the pylon drain tube, in accordance with Boeing Alert
Service Bulletin 767-71A0082, dated July 6, 1995.
(b) 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, Seattle Aircraft Certification
Office (ACO), FAA, Transport Airplane Directorate. Operators shall
submit their requests through an appropriate FAA Principal
Maintenance Inspector, who may add comments and then send it to the
Manager, Seattle ACO.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Seattle ACO.
(c) 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 airplane to a location where
the requirements of this AD can be accomplished.
Issued in Renton, Washington, on January 25, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 96-1876 Filed 1-30-96; 8:45 am]
BILLING CODE 4910-13-U
