[Federal Register Volume 65, Number 247 (Friday, December 22, 2000)]
[Proposed Rules]
[Pages 80796-80798]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-32765]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-309-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 767 Series Airplanes

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. For certain airplanes this proposal would require rework of 
the bonding jumper assemblies. For certain other airplanes, this 
proposal would require repetitive inspections of the drain tube 
assemblies of the slat track housing of the wings to find 
discrepancies, and corrective actions, if necessary. This proposal also 
provides for terminating action for the repetitive inspections. This 
action is necessary to find and fix discrepancies of the bonding jumper 
assemblies, which could result in electrostatic discharge and an in-
tank ignition source. This action also is necessary to find and fix 
discrepancies of the fuel drain tubes, which could result in fuel 
migrating into the tubes and leaking onto an engine or exhaust nozzle, 
and consequent risk of a fire when the airplane is stationary or during 
low speed taxiing. This action is intended to address the identified 
unsafe conditions.

DATES: Comments must be received by February 5, 2001.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2000-NM-309-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. Comments may be submitted via fax to (425) 227-1232. 
Comments may also be sent via the Internet using the following address: 
[email protected]. Comments sent via fax or the Internet must 
contain ``Docket No. 2000-NM-309-AD'' in the subject line and need not 
be submitted in triplicate. Comments sent via the Internet as attached 
electronic files must be formatted in Microsoft Word 97 for Windows or 
ASCII text.
    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: Dennis Kammers, Aerospace Engineer, 
Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification 
Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone 
(425) 227-2956; fax (425) 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 action may be changed in 
light of the comments received.
    Submit comments using the following format:
     Organize comments issue-by-issue. For example, discuss a 
request to change the compliance time and a request to change the 
service bulletin reference as two separate issues.
     For each issue, state what specific change to the proposed 
AD is being requested.
     Include justification (e.g., reasons or data) for each 
request.
    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 action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2000-NM-309-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-114, Attention: Rules 
Docket No. 2000-NM-309-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received reports on certain Boeing Model 767 series 
airplanes that a new drain tube assembly was installed during 
production, and the manufacturer determined that the bonding jumper 
assembly on the installation did not meet the current bonding 
specifications. Such discrepancies of the bonding jumper assemblies 
could result in electrostatic discharge and an intank ignition source.
    For certain other airplanes, the FAA has received reports of the 
detection of fuel leaks from the number 5 and number 8 drain locations 
of the slat track housing near the engine exhaust nozzles of the wings. 
One report showed that the fuel leak originated from a drain tube 
fitting that had loosened over time. The other reports showed that the 
fuel leaks originated from a crack in each of the drain tubes due to 
improper

[[Page 80797]]

installation. Such discrepancies of the fuel drain tubes could result 
in fuel migrating into the tubes and leaking onto an engine or exhaust 
nozzle, and consequent risk of a fire when the airplane is stationary 
or during low speed taxiing.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Service Bulletin 767-
57A0060, Revision 1, dated December 31, 1998, which describes 
procedures for repetitive visual inspections of the drain tube 
assemblies of the slat track housing of the wings to find discrepancies 
(loose fittings and/or cracking of the fuel drain tubes); rework of the 
drain tube assemblies if any discrepancies are found; and eventual 
replacement of the drain tube assemblies, which would constitute 
terminating action for the repetitive inspections.
    The FAA also has reviewed and approved Boeing Service Bulletin 767-
57-0068, dated September 16, 1999, which describes procedures for 
rework of the bonding jumper assembly of the number 5 and number 8 
drain tube assemblies of the inboard slat track that were installed 
before per a production change (PRRB12900-133) that was incorporated at 
the manufacturer's facility. The rework includes, but is not limited 
to, replacement of the fasteners common to the drain doubler assembly; 
installation of bonding jumper brackets to the rib stiffeners, and 
installation of bonding jumpers between the drain tube assemblies and 
the brackets installed on the rib panels.
    Accomplishment of the actions specified in the service bulletins is 
intended to adequately address the identified unsafe conditions.

Explanation of Requirements of Proposed Rule

    Since two unsafe conditions have been identified that are likely to 
exist or develop on other products of this same type design, the 
proposed AD would require accomplishment of the actions specified in 
the service bulletins described before, except as discussed below.

Differences Between Boeing Service Bulletin 767-57A0060, Revision 
1, and This Proposed Rule

    Operators should note that the service bulletin does not direct 
operators to do the initial and repeat visual inspections of the drain 
tube assemblies of the slat track housing of the wings to find leakage, 
if the inspection recommended in the Boeing 767 Maintenance Planning 
Document (MPD), Section 57-59-00-A, has been accomplished. This 
proposed rule would require accomplishment of the initial and repeat 
visual inspections regardless of earlier accomplishment of the 
inspection specified in the MPD.
    Operators also should note that this AD proposes to mandate, within 
6,000 flight hours or 18 months, whichever occurs first, the 
replacement of the drain tube assemblies of the slat track housing of 
the wings described in the service bulletin as terminating action for 
the repetitive inspections. (The service bulletin states that 
incorporation of the terminating action specified is optional.) The FAA 
has determined that long-term continued operational safety will be 
better assured by design changes to remove the source of the problem, 
rather than by repetitive inspections. Long-term inspections may not be 
providing the degree of safety assurance necessary for the transport 
airplane fleet. This, coupled with a better understanding of the human 
factors associated with numerous continual inspections, has led the FAA 
to consider placing less emphasis on inspections and more emphasis on 
design improvements. The proposed replacement is consistent with these 
conditions.
    Part IV of the Accomplishment Instructions of the service bulletin 
identifies certain rework specified in the ``Validation Copy 1'' 
release of the service bulletin as part of the corrective action. The 
FAA does not recognize work done using a validation copy of the service 
bulletin because it is not an FAA-approved document and, therefore, 
Part IV of the service bulletin is not required by this proposed rule.

Cost Impact

    There are approximately 745 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 275 airplanes of U.S. registry 
would be affected by this proposed AD.
    For airplanes listed in Boeing Service Bulletin 767-57A0060, 
Revision 1 (228 U.S.-registered airplanes): It would take approximately 
1 work hour per airplane to accomplish the proposed inspection, at an 
average labor rate of $60 per work hour. Based on these figures, the 
cost impact of the proposed inspection on U.S. operators is estimated 
to be $13,680, or $60 per airplane, per inspection cycle.
    It would take approximately 12 work hours per airplane to 
accomplish the proposed replacement of the drain tube assemblies 
specified in Boeing Service Bulletin 767-57A0060, Revision 1, at an 
average labor rate of $60 per work hour. Required parts would cost 
approximately $5,236 per airplane. Based on these figures, the cost 
impact of the proposed replacement on U.S. operators is estimated to be 
$1,357,968, or $5,956 per airplane.
    For airplanes listed in Boeing Service Bulletin 767-57-0068, (47 
U.S.-registered airplanes): It would take approximately 4 work hours 
per airplane to accomplish the proposed rework of the bonding jumper 
assemblies, at an average labor rate of $60 per work hour. Required 
parts would cost approximately $322 per airplane. Based on these 
figures, the cost impact of the proposed rework on U.S. operators is 
estimated to be $26,414, or $562 per airplane.
    The cost impact figures discussed above are 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 proposed AD were not adopted. The cost impact 
figures discussed in AD rulemaking actions represent only the time 
necessary to do the specific actions actually required by the AD. These 
figures typically do not include incidental costs, such as the time 
required to gain access and close up, planning time, or time needed by 
other administrative actions.

Regulatory Impact

    The regulations proposed herein would 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. Therefore, it 
is determined that this proposal would not have federalism implications 
under Executive Order 13132.
    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.

[[Page 80798]]

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 adding the following new 
airworthiness directive:

Boeing: Docket 2000-NM-309-AD.

    Applicability: Model 767 series airplanes, line numbers 1 
through 757 inclusive, 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 request approval for an 
alternative method of compliance per paragraph (d) of this AD. The 
request should include an assessment of the effect of the 
modification, alteration, or repair on the unsafe conditions 
addressed by this AD; and, if the unsafe conditions have not been 
eliminated, the request should include specific proposed actions to 
address it.


    Compliance: Required as indicated, unless accomplished before.
    To find and fix discrepancies (bonding, loose fittings, 
cracking) of the bonding jumper assemblies, which could result in 
electrostatic discharge and an in-tank ignition source; and of the 
fuel drain tubes, which could result in fuel migrating into the 
tubes and leaking onto an engine or exhaust nozzle, and consequent 
risk of a fire when the airplane is stationary or during low speed 
taxiing; accomplish the following:

Repetitive Inspections/Corrective Action

    (a) For airplanes listed in Boeing Service Bulletin 767-57A0060, 
Revision 1, dated December 31, 1998; within 500 flight hours after 
the effective date of this AD: Do a general visual inspection of the 
drain tube assemblies of the slat track housings of the wings to 
find discrepancies (loose fittings, cracked tubes, fuel leaks), per 
Part I of the Accomplishment Instructions of the service bulletin.
    (1) If any discrepancies are found, before further flight, 
rework the drain tube assembly per Part II of the Accomplishment 
Instructions of the service bulletin; repeat the inspection at 
intervals not to exceed 500 flight hours until accomplishment of the 
requirements in paragraph (b) of this AD.
    (2) If no discrepancies are found, repeat the inspection 
thereafter at intervals not to exceed 500 flight hours, until 
accomplishment of the requirements in paragraph (b) of this AD.


    Note 2: For the purposes of this AD, a general visual inspection 
is defined as: ``A visual examination of an interior or exterior 
area, installation, or assembly to find obvious damage, failure, or 
irregularity. This level of inspection is made under normally 
available lighting conditions such as daylight, hangar lighting, 
flashlight, or drop-light and may require removal or opening of 
access panels or doors. Stands, ladders, or platforms may be 
required to gain proximity to the area being checked.''


Terminating Action for Repetitive Inspections

    (b) For airplanes specified in paragraph (a) of this AD; within 
6,000 flight hours or 18 months after the effective date of this AD, 
whichever occurs first: Replace the drain tube assemblies of the 
slat track housings of the wings (including general visual 
inspection and repair) per Part III of the Accomplishment 
Instructions of Boeing Service Bulletin 767-57A0060, Revision 1, 
dated December 31, 1998. Any applicable repair must be accomplished 
prior to further flight. Accomplishment of this paragraph terminates 
the repetitive inspections required by paragraph (a) of this AD.

Rework of Bonding Jumper Assemblies

    (c) For airplanes listed in Boeing Service Bulletin 767-57-0068, 
dated September 16, 1999; within 5,000 flight cycles or 22 months 
after the effective date of this AD, whichever occurs first: Rework 
the bonding jumper assembly of the drain tube assemblies of the slat 
track housing of the wings (including general visual inspection and 
repair) per the Accomplishment Instructions of the service bulletin. 
Any applicable repair must be accomplished prior to further flight. 
Accomplishment of this paragraph terminates the requirements of this 
AD.

Alternative Methods of Compliance

    (d) 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. Operators shall send their requests through an 
appropriate FAA Principal Maintenance Inspector, who may add 
comments and then send it to the Manager, Seattle ACO.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

Special Flight Permit

    (e) Special flight permits may be issued per 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 December 18, 2000.
Dorenda D. Baker,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-32765 Filed 12-21-00; 8:45 am]
BILLING CODE 4910-13-U