[Federal Register Volume 62, Number 127 (Wednesday, July 2, 1997)]
[Proposed Rules]
[Pages 35711-35713]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-17285]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-39-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 supersedure of an existing 
airworthiness directive (AD), applicable to certain Boeing Model 767 
series airplanes, that currently requires an inspection to detect 
damage of the wire bundles in the left side of the flight compartment 
in the vicinity of the stowage box for the captain's oxygen mask, and 
repair, if necessary; a continuity check on repaired wires; 
installation of sleeving over the wire bundles; and rerouting of

[[Page 35712]]

the wire bundles. This action would require modifications of the 
captain's and first officer's consoles in the flight compartment to 
ensure adequate clearance between oxygen equipment and adjacent wire 
bundles. This proposal is prompted by reports indicating that chafed 
wiring and wire insulation wear occurred in the vicinity of the stowage 
box for the captain's oxygen mask due to interference between oxygen 
line fittings and adjacent wire bundles. The actions specified by the 
proposed AD are intended to prevent such chafing and inadequate 
clearance, which could result in electrical arcing and consequent 
oxygen leakage in the vicinity of the stowage box; these conditions, if 
not corrected, could result in a fire in the flight compartment.

DATES: Comments must be received by August 11, 1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 97-NM-39-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: Susan Letcher, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington; 
telephone (425) 227-2670; 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 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-NM-39-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. 97-NM-39-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On October 2, 1995, the FAA issued AD 95-21-05, amendment 39-9390 
(60 FR 52844, October 11, 1995), applicable to certain Boeing Model 767 
airplanes, to require a one-time inspection to detect damage of the 
wire bundles in the left side of the flight compartment in the vicinity 
of the stowage box for the captain's oxygen mask, and repair, if 
necessary; a continuity check on repaired wires; installation of 
sleeving over the wire bundles; and rerouting of the wire bundles. That 
action was prompted by reports of chafed wiring and minimal clearance 
between the oxygen connector and the adjacent wire bundles in the 
vicinity of the stowage box for the captain's oxygen mask. The 
requirements of that AD are intended to prevent such chafing and 
inadequate clearance, which could result in electrical arcing and 
consequent oxygen leakage in the vicinity of the stowage box; these 
conditions, if not corrected, could result in a fire in the flight 
compartment.

Actions Since Issuance of Previous Rule

    In the preamble to AD 95-21-05, the FAA indicated that the actions 
required by that AD were considered ``interim action'' and that further 
rulemaking action was being considered. The FAA now has determined that 
further rulemaking action is indeed necessary, and this AD follows from 
that determination.
    Additionally, since the issuance of that AD, a number of reports 
have been received that indicate interference between oxygen line 
fittings on the stowage box for the captain's oxygen mask and adjacent 
wire bundles. This condition, if not corrected, could cause wires on 
the oxygen line fittings to chafe, which could lead to possible 
electrical arcing with the fitting, a hole in the fitting, and an 
oxygen leak; and result in an uncontrolled fire in the flight 
compartment.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Alert Service Bulletin 
767-35A0029, dated January 30, 1997, which describes procedures for 
modifications of the captain's and first officer's consoles in the 
flight compartment to ensure adequate clearance between oxygen 
equipment and adjacent wire bundles. At the disconnect panel on the 
captain's console, modification includes rerouting wires and installing 
certain components. At the first officer's console, modification 
includes installing certain components, such as a 90-degree backshell 
on the electrical connector to the dimmer module and a new bracket 
assembly. Ensuring adequate clearance between the oxygen system 
components and adjacent wire bundles will reduce the potential for 
future wire chafing on the consoles in the flight compartment.

Explanation of Requirements of Proposed Rule

    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 95-21-05 to continue to require an 
inspection to detect damage of the wire bundles in the left side of the 
flight compartment in the vicinity of the stowage box for the captain's 
oxygen mask, and repair, if necessary; a continuity check on repaired 
wires; installation of sleeving over the wire bundles; and rerouting of 
the wire bundles. The proposed AD also would require modifications of 
the captain's and first officer's consoles in the flight compartment to 
ensure adequate clearance between oxygen equipment and adjacent wire 
bundles. The actions would be required to be accomplished in accordance 
with the alert service bulletin described previously.

Cost Impact

    There are approximately 568 Boeing Model 767 series airplanes of 
the affected design in the worldwide fleet. The FAA estimates that 185 
airplanes of U.S. registry would be affected by this proposed AD.

[[Page 35713]]

    The actions that are currently required by AD 95-21-05 take 
approximately 3 work hours per airplane to accomplish, at an average 
labor rate of $60 per work hour. Required parts cost approximately $50 
per airplane. Based on these figures, the cost impact of the currently 
required actions on U.S. operators is estimated to be $42,550, or $230 
per airplane.
    The new actions that are proposed in this AD action would take 
approximately 11 work hours per airplane to accomplish, at an average 
labor rate of $60 per work hour. Required parts would cost 
approximately $479 per airplane. Based on these figures, the cost 
impact of the proposed requirements of this AD on U.S. operators is 
estimated to be $210,715, or $1,139 per airplane.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the current or proposed 
requirements of this AD action, and that no operator would accomplish 
those actions in the future if this AD were not adopted.

Regulatory Impact

    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 39-9390 (60 FR 
52844, October 11, 1995), and by adding a new airworthiness directive 
(AD), to read as follows:

Boeing: Docket 97-NM-39-AD. Supersedes AD 95-21-05, Amendment 39-
9390.

    Applicability: Model 767 series airplanes, as listed in Boeing 
Alert Service Bulletin 767-35A0029, dated January 30, 1997; 
certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
otherwise 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 in accordance with paragraph (c) 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 wire chafing and subsequent electrical arcing in the 
vicinity of the stowage box for the captain's oxygen mask, which 
could result in a fire in the flight compartment, accomplish the 
following:

Restatement of Requirements of AD 95-21-05

    (a) For Model 767 series airplanes having line positions 2 
through 589 inclusive except VA801 through VA810 inclusive, VN684 
through VN691 inclusive, and VW701: Within 45 days after October 26, 
1995 (the effective date of AD 95-21-05, amendment 39-9390), inspect 
to detect damage of the wire bundles in the left side of the flight 
compartment in the vicinity of the stowage box for the captain's 
oxygen mask, in accordance with Boeing Alert Service Bulletin 767-
35A0028, dated September 7, 1995.
    (1) If no damage is detected, prior to further flight, install 
protective sleeving on the wiring, and reroute the wire bundles, in 
accordance with the alert service bulletin.
    (2) If any damage is detected, prior to further flight, 
accomplish the requirements of paragraphs (a)(2)(i) and (a)(2)(ii) 
of this AD.
    (i) Repair the wiring and perform a continuity check on each 
repaired wire, in accordance with the alert service bulletin. And
    (ii) Install protective sleeving on the wiring and reroute the 
wire bundles, in accordance with the alert service bulletin.

New Requirements of This AD

    (b) For all airplanes: Within 18 months after the effective date 
of this AD, modify the airplane wiring in the vicinity of the 
captain's and first officer's consoles, in accordance with Boeing 
Alert Service Bulletin 767-35A0029, dated January 30, 1997. 
Accomplishment of this modification constitutes terminating action 
for the inspection requirements of this AD.
    (c) 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.

    (d) 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 June 26, 1997.
S.R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-17285 Filed 7-1-97; 8:45 am]
BILLING CODE 4910-13-U