[Federal Register Volume 66, Number 93 (Monday, May 14, 2001)]
[Proposed Rules]
[Pages 24306-24308]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-12009]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-351-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 767-200 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 767-200 
series airplanes. This proposal would require replacement of certain 
duct assemblies of the air distribution system for the flight 
compartment with new duct assemblies with improved insulation, and 
follow-on actions. This action is necessary to prevent ignition of foam 
insulation on the air distribution ducts, which could result in a fire 
in the airplane. This action is intended to address the identified 
unsafe condition.

DATES: Comments must be received by June 28, 2001.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2000-NM-351-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-351-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: Don Eiford, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-
4056; telephone (425) 227-2788; 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-351-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-351-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received a report that an operator found burned 
insulation on an air distribution system duct located in the 
Electronics and Electrical (E/E) bay. The burned insulation was 
discovered while the airplane was on the ground when a maintenance crew 
noticed an odor of burning. Investigation revealed that the ignition 
source was an overheated heater tape for the water line. Polyurethane 
foam insulation which was touching the water line heater tape ignited 
and burned completely. The foam had lost its original fire-retardant 
properties. The reason for the degradation of the foam's fire retardant 
properties is unknown; however, contamination and aging of the material 
are suspected. Ignition of foam insulation on the air distribution 
ducts could result in a fire in the airplane.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Alert Service Bulletin 
767-21A0154, dated March 16, 2000, which describes procedures for 
replacement of certain duct assemblies of the air distribution system 
for the flight compartment (which are located under the main deck) with 
new duct assemblies having fiberglass insulation. The service bulletin 
also describes procedures for a general visual inspection of the water 
line heater tape where it passes close to the new duct assembly to 
detect damage such as wear, chafing, pinching, discoloration, or 
localized burn marks. The service bulletin specifies that any damaged 
tape should be replaced with new heater tape. If no damage is found, 
the service bulletin specifies that any heater tape that is too close 
to the new duct assemblies must be rerouted to increase the distance 
between the water line heater tape and duct insulation. Accomplishment 
of the actions specified in the service bulletin is intended to 
adequately address the identified unsafe condition.

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 require accomplishment of the actions specified in 
the service bulletin

[[Page 24307]]

described previously, except as discussed below.

Differences Between Proposed Rule and Service Bulletin

    Operators should note that the service bulletin does not define 
appropriate clearance between the new duct assemblies and the water 
line heater tape. This proposed AD would require that a minimum 
clearance of 0.25 inch be maintained between the new duct assemblies 
and the water line heater tape.
    Also, operators should note that the service bulletin recommends 
accomplishment of the actions in that bulletin at the earliest 
opportunity. The FAA finds that a more definite compliance time is 
necessary to ensure that the proposed actions are done in a timely 
manner. Therefore, the proposed AD would require the replacement of the 
duct assemblies with new assemblies and the other follow-on actions be 
accomplished within 18 months after the effective date of the AD. The 
FAA finds that such a compliance time is adequate to ensure the safety 
of the airplane fleet while allowing enough time so that the majority 
of affected operators would be able to accomplish the proposed 
requirements at a normal scheduled maintenance visit.

Cost Impact

    There are approximately 81 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 52 airplanes of U.S. registry 
would be affected by this proposed AD, that it would take approximately 
2 work hours per airplane to accomplish the proposed actions, and that 
the average labor rate is $60 per work hour. Required parts would cost 
a maximum of $7,285 per airplane. Based on these figures, the cost 
impact of the proposed AD on U.S. operators is estimated to be 
$385,060, or $7,405 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 proposed AD were not adopted. The cost impact 
figures discussed in AD rulemaking actions represent only the time 
necessary to perform 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 
necessitated 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.

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-351-AD.

    Applicability: Model 767-200 series airplanes, as listed in 
Boeing Alert Service Bulletin 767-21A0154, dated March 16, 2000; 
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 in accordance with paragraph (b) 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 ignition of foam insulation on the air distribution 
ducts, which could result in a fire in the airplane, accomplish the 
following:

Replacement and Follow-On Actions

    (a) Within 18 months after the effective date of this AD, do the 
actions specified in paragraphs (a)(1) and (a)(2) of this AD per the 
Accomplishment Instructions of Boeing Alert Service Bulletin 767-
21A0154, dated March 16, 2000.
    (1) Replace subject duct assemblies of the air distribution 
system for the flight compartment (which are located under the main 
deck) with new duct assemblies having fiberglass insulation.
    (2) Before further flight after replacement of the ducts, 
perform a one-time general visual inspection of the water line 
heater tape where it passes close to the new duct assemblies to 
detect damage, including wear, chafing, pinching, discoloration, 
localized burn marks, etc.
    (i) If no damage is detected, measure the clearance between the 
new duct assemblies and the water line heater tape. If clearance is 
less than 0.25 inch, re-route the heater tape per the service 
bulletin.
    (ii) If any damage is detected, before further flight, replace 
the heater tape with new heater tape, per the service bulletin. When 
installing the new tape, make sure that clearance between the water 
line heater tape and the new duct assemblies is a minimum of 0.25 
inch.

    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 detect 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.''

Alternative Methods of Compliance

    (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. 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 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 Permits

    (c) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR

[[Page 24308]]

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 May 8, 2001.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-12009 Filed 5-11-01; 8:45 am]
BILLING CODE 4910-13-U