[Federal Register Volume 63, Number 63 (Thursday, April 2, 1998)]
[Rules and Regulations]
[Pages 16096-16098]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-8350]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-50-AD; Amendment 39-10433; AD 98-07-13]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 767-200 and -300 Series 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to certain Boeing Model 767-200 and -300 series airplanes, 
that requires a one-time inspection for worn or broken wire bundles in 
the ceiling above the main passenger door and repair, if necessary; and 
relocation of the wire bundles to prevent chafing. This amendment is 
prompted by a report indicating that the opening of the main passenger 
door caused the door liner and a ceiling panel to chafe and ultimately 
break wires installed in this area. The actions specified by this AD 
are intended to prevent these wires from becoming worn or breaking, 
which could lead to the failure of several systems, such as the fuel 
shutoff valves, and may contribute to the inability of the flight crew 
to stop the flow of fuel to the engines in the event of an engine fire.

DATES: Effective May 7, 1998.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of May 7, 1998.

ADDRESSES: The service information referenced in this AD may be 
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, 
Washington 98124-2207. This information may be examined at the Federal 
Aviation Administration (FAA), Transport Airplane Directorate, Rules 
Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of 
the Federal Register, 800 North Capitol Street, NW., suite 700, 
Washington, DC.

FOR FURTHER INFORMATION CONTACT: Stephen S. Oshiro, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-
4056; telephone (425) 227-2793; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to certain Boeing Model 767-200 and -
300 series airplanes was published in the Federal Register on June 6, 
1997 (62 FR 31021). That action proposed to require a one-time 
inspection for worn or broken wire bundles in the ceiling above the 
main passenger door and repair, if necessary; and relocation of the 
wire bundles to prevent chafing.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Support for the Proposal

    Two commenters support the proposed rule.

Request To Add New Service Information

    One commenter requests including the phrase ``as amended by Notice 
of Status Change 767-33-0052 NSC 01, dated May 9, 1996'' in the final 
rule after each reference to Boeing Service Bulletin 767-33-0052, 
Revision 1, dated December 8, 1994. This commenter states that the 
Notice of Status Change (NSC) specifies that a larger wire clamp is 
required than was specified in Revision 1 of the service bulletin.
    The FAA concurs. The FAA has determined that the wire bundle clamp 
specified in the previously referenced service bulletin may be too 
small for two of the wire bundles on Model 767-200 and -300 series 
airplanes. For this reason, the FAA considers that the larger wire 
clamp specified in the previously referenced NSC will provide operators 
with the proper size clamp, and has changed the final rule accordingly.

Request To Change Discussion Section of Proposal

    One commenter requests two changes to the wording in the Discussion 
section of the proposal:
    1. In the first sentence of the second paragraph, which reads 
``Because these wires are connected to such safety systems as the fuel 
shutoff valves for the engines * * *,'' the commenter requests deleting 
the word ``safety'' from ``safety system.'' The commenter states that 
it is incorrect to identify these systems as ``safety systems'' because 
if any of the systems fail, a second failure would be required to cause 
a safety problem.
    The FAA concurs partially. The FAA does not agree that these 
systems are unrelated to safety. When evaluating the loss of functions 
that protect the airplane from hazardous events, the FAA assumes the 
existence of the

[[Page 16097]]

hazard. In the case of worn or broken wiring to the engine fuel shutoff 
valve, the FAA considers that the inability of the flight crew to close 
the shutoff valve, given the existence of an engine fire, is a 
hazardous condition that warrants mandatory corrective action. The FAA 
considers that changing ``safety systems'' to ``systems related to 
airplane or passenger safety'' would add clarity to the final rule; 
however, no change to this final rule is necessary since neither the 
Discussion section nor the term ``safety systems'' appear in the final 
rule.
    2. In the second sentence of the second paragraph, the commenter 
states that the following statement should be deleted from the final 
rule: ``Such failure of the fuel shutoff valves, for example, would 
prevent the flight crew from stopping the flow of fuel to the engines 
in the event of a fire.'' The commenter states that this statement is 
incorrect because ``the subject wiring failure will affect only the 
fire handle electrical path to the fuel shutoff valve.'' The commenter 
maintains that the redundant fuel control switch path would be 
unaffected by this failure and that the valve could be closed in case 
of an engine fire.
    The FAA concurs partially. The FAA does not agree that the valve 
could be closed in case of an engine fire if the fuel control switch 
failed; however, the FAA does agree to clarify the wording of the final 
rule in certain sections.
    After evaluating the design of the engine fuel shutoff valve system 
of the Model 767 series airplane, the FAA has determined the following. 
First, although in the event of the subject wiring failure, the fuel 
shutoff valve could be closed via the engine fuel shutoff valve, the 
ability to close this valve is dependent on the actuation of the fuel 
control switch by the flight crew before the engine fire handle is 
pulled, as specified by the Emergency Procedures section of the Model 
767 Airplane Flight Manual. Second, the engine fuel shutoff valve 
cannot be closed if the fire handle is pulled before the fuel control 
switch is placed in the ``Cutoff'' position.
    Because of these findings, the FAA has determined that a procedural 
deviation, such as pulling the fire handle first, could occur under 
certain circumstances, which would result in the inability to stop the 
flow of fuel to an engine fire. Further, the FAA has determined that 
the final rule should continue to identify the loss of fuel shutoff 
capability as a possible consequence of the wire chafing condition.
    The Discussion section does not appear in the final rule; however, 
the FAA has changed the wording in the Summary section of this final 
rule and the section that describes the unsafe condition to address the 
commenter's concern. In these sections the final rule now reads ``Wire 
bundle damage may contribute to the inability of the flight crew to 
stop the flow of fuel to the engines in the event of an engine fire'' 
instead of ``* * * would prevent the flight crew * * *.''

Conclusion

    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the changes previously 
described. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.

Cost Impact

    There are approximately 403 Model 767-200 and -300 series airplanes 
of the affected design in the worldwide fleet. The FAA estimates that 
142 airplanes of U.S. registry will be affected by this AD.
    It will take approximately 1 work hour per airplane to accomplish 
the required inspection, at an average labor rate of $60 per work hour. 
Based on these figures, the cost impact of the inspection on U.S. 
operators is estimated to be $8,520, or $60 per airplane.
    It will take approximately 57 work hours per airplane to accomplish 
the required relocation of the wire bundles, at an average labor rate 
of $60 per work hour. Required parts will cost approximately $200 per 
airplane. Based on these figures, the cost impact of the required 
relocation of the wire bundles on U.S. operators is estimated to be 
$514,040, or $3,620 per airplane.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the 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 adopted herein will 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 final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
from the Rules Docket at the location provided under the caption 
ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 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:

98-07-13  Boeing: Amendment 39-10433. Docket 97-NM-50-AD.

    Applicability: Model 767-200 and -300 series airplanes; as 
listed in Boeing Service Bulletin 767-33-0052, Revision 1, dated 
December 8, 1994, as revised by Notice of Status Change 767-33-0052 
NSC 01, dated May 9, 1996; 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.

[[Page 16098]]

    To prevent wires in the area above the main passenger door from 
becoming worn or breaking, which could lead to the failure of 
several systems, such as the fuel shutoff valves, and may contribute 
to the inability of the flight crew to stop the flow of fuel to the 
engines in the event of an engine fire, accomplish the following:
    (a) Within 12 months after the effective date of this AD, 
conduct a one-time inspection to detect worn or broken wires in the 
wire bundles installed above the main passenger door, in accordance 
with Boeing Service Bulletin 767-33-0052, Revision 1, dated December 
8, 1994, as revised by Notice of Status Change 767-33-0052 NSC 01, 
dated May 9, 1996. Prior to further flight, repair any worn or 
broken wires and relocate the wire bundles inboard of this door, in 
accordance with the service bulletin. Thereafter, no further action 
is required by this AD.

    Note 2: Inspection; repair, if necessary; and relocation of the 
wire bundles accomplished prior to the effective date of this AD in 
accordance with Boeing Service Bulletin 767-33-0052, dated April 2, 
1992, is considered acceptable for compliance with the requirements 
of paragraph (a) of this AD.

    (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 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Manager, 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.
    (d) The actions shall be done in accordance with Boeing Service 
Bulletin 767-33-0052, Revision 1, dated December 8, 1994; as revised 
by Notice of Status Change 767-33-0052 NSC 01, dated May 9, 1996. 
This incorporation by reference was approved by the Director of the 
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 
51. Copies may be obtained from Boeing Commercial Airplane Group, 
P.O. Box 3707, Seattle, Washington 98124-2207. Copies may be 
inspected at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue, SW., Renton, Washington; or at the Office of the Federal 
Register, 800 North Capitol Street, NW., suite 700, Washington, DC.
    (e) This amendment becomes effective on May 7, 1998.

    Issued in Renton, Washington, on March 25, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-8350 Filed 4-1-98; 8:45 am]
BILLING CODE 4910-13-U