[Federal Register Volume 61, Number 73 (Monday, April 15, 1996)]
[Rules and Regulations]
[Pages 16377-16379]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-8295]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 95-NM-131-AD; Amendment 39-9565; AD 96-07-15]


Airworthiness Directives; McDonnell Douglas Model DC-9, DC-9-80, 
and MD-90-30 Series Airplanes, Model MD-88 Airplanes, and C-9 
(Military) Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD), applicable to certain McDonnell Douglas Model DC-9-80 series 
airplanes and Model MD-88 airplanes, that currently requires an 
inspection to detect chafing of or damage to the wire bundle in the 
overhead switch panel of the cockpit, application of spiral wrap to the 
wire bundle, and corrective actions, if necessary. That AD was prompted 
by reports of chafed and shorted wires that resulted in smoke emanating 
from the overhead switch panel of the cockpit. This amendment expands 
the applicability of the rule to include certain Model DC-9 and MD-90-
30 series airplanes, and C-9 (military) series airplanes. This 
amendment also adds a requirement to reroute the wire bundle to 
preclude chafing and damage. The actions specified by this AD are 
intended to prevent the potential for fire and uncontrolled smoke 
throughout the cockpit as a result of chafing and shorting in the 
electrical wire bundles.

DATES: Effective May 15, 1996.
    The incorporation by reference of certain publications, as listed 
in the regulations, is approved by the Director of the Federal Register 
as of May 15, 1996.
    The incorporation by reference of McDonnell Douglas Alert Service 
Bulletin DC9-24A157, dated April 11, 1995, as listed in the 
regulations, was approved previously by the Director of the Federal 
Register as of May 19, 1995 (60 FR 21977, May 4, 1995).

ADDRESSES: The service information referenced in this AD may be 
obtained from McDonnell Douglas Corporation, 3855 Lakewood Boulevard, 
Long Beach, California 90846, Attention: Technical Publications 
Business Administration, Department C1-L51 (2-60). 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 FAA, Los Angeles Aircraft Certification Office, 
Transport Airplane Directorate, 3960 Paramount Boulevard, Lakewood, 
California; or at the Office of the Federal Register, 800 North Capitol 
Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: J. Kirk Baker, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130L, FAA, Los Angeles Aircraft 
Certification Office, 3960 Paramount Boulevard, Lakewood, California 
90712; telephone (310) 627-5345; fax (310) 627-5210.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) by superseding AD 95-09-10, 
amendment 39-9213 (60 FR 21977, May 4, 1995), which currently is 
applicable to certain McDonnell Douglas Model DC-9-80 series airplanes 
and Model MD-88 airplanes, was published in the Federal Register on 
September 15, 1995 (60 FR 47901). The action proposed to supersede AD 
95-09-10 to continue to require a one-time visual inspection to detect 
chafing of or damage to the wire bundle in the overhead switch panel of 
the cockpit, application of spiral wrap to the wire bundle, repair of 
chafed wire insulation, splicing of damaged wires, and rerouting the 
wire bundle. The action also proposed to expand the applicability of 
the rule to include certain Model DC-9 and MD-90-30 series airplanes, 
and C-9 (military) series airplanes. This amendment also adds a 
requirement to reroute the wire bundle to preclude chafing and damage.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.
    One commenter supports the proposed rule.
    Two commenters request that Model DC-9 series airplanes be excluded 
from the applicability of the proposal. One of these commenters states 
that the FAA has not proven that the potential for chafing of wire 
bundles exists for Model DC-9 series airplanes. The other commenter 
states that it has inspected 35 in-service airplanes in its fleet and 
has found only one chafed wire bundle, and has never, in 25 years of 
service, found any damaged wire bundles.
    The FAA does not concur. Although there have been no reported cases 
of damage to the wire bundle on any in-service Model DC-9 series 
airplane, the FAA has received reports of chafing found on the wire 
bundle on in-service Model DC-9 series airplanes. Therefore, the 
potential for damage still exists when the wire bundle is improperly 
routed in the overhead switch panel of the cockpit such that chafing 
occurs. The FAA has determined that rerouting the wire bundle will 
prevent the potential for chafing and thereby prevent the potential for 
a consequent fire and uncontrolled smoke throughout the cockpit.
    Two commenters request a revision to paragraph (b) of the proposal 
to delete the requirement to apply spiral wrap to the wire bundle 
following findings of chafing or damage to the wire bundle on Model DC-
9, MD-90-30, and C-9 (military) series airplanes. The commenters state 
that these airplanes should not be required to apply spiral wrap, since 
the proposal also requires rerouting of the wire bundles following 
application of spiral wrap.
    The FAA concurs. Since issuance of the NPRM, the FAA has reviewed 
and approved McDonnell Douglas Service Bulletins DC9-24-157 and MD90-
24-001, both dated November 9, 1995, which describe procedures for 
rerouting the electrical wiring in the overhead switch panel to clear 
the cabin temperature indicator housing. As explained in the preamble 
to AD 95-09-10, the FAA considers the application of spiral wrap to be 
only a temporary measure to protect against chafing of the wire bundle. 
The FAA's intent was to require, in AD 95-09-10, application of spiral 
wrap only for Model DC-9-80 series airplanes and Model MD-88 airplanes, 
since the procedures to reroute the wire bundles for these airplanes 
had not yet been developed at the time AD 95-09-10 was issued. Since 
procedures for rerouting the wire bundles have now been developed for 
all airplanes, the FAA finds that operators must reroute the wire 
bundles immediately following findings of chafed or damaged wire 
bundles on Model DC-9, MD-90-30, and C-9 (military) series airplanes. 
The FAA has determined that applying the spiral

[[Page 16378]]

wrapping for these airplanes would not necessarily enhance safety, and 
would cause operators to incur an unnecessary expense. Consequently, 
paragraph (b) of the final rule has been revised to remove the 
requirement to spiral wrap the wire bundle prior to rerouting the wire 
bundle. Additionally, paragraph (b) of the final rule has been revised 
to reference McDonnell Douglas Service Bulletins DC9-24-157 and MD90-
24-001 as additional sources of service information to accomplish 
rerouting of the wire bundle.
    Additionally, the FAA has revised paragraph (c) of the final rule 
to include an applicability statement that limits the requirement of 
that paragraph (rerouting the wire bundles within 6 months after the 
effective date of the AD) to only Model DC-9-80 series airplanes and 
Model MD-88 airplanes . [The requirement to reroute the wire bundle for 
all other airplanes is required immediately following the inspection 
required by paragraph (b) of the final rule.]
    Two commenters request that previously approved alternative methods 
of compliance (AMOC) with AD 95-09-10 continue to be acceptable for the 
requirements of the proposal. The commenters state that such a 
provision in the proposal would preclude operators from having to 
obtain approval of additional AMOC's unnecessarily. The FAA concurs. 
NOTE 3 from the proposal has been changed from a note to paragraph 
(d)(2) of the final rule to emphasize that operators need not apply for 
approval of an additional AMOC if the FAA had previously approved an 
AMOC to AD 95-09-10.
    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.
    There are approximately 2,012 Model DC-9, DC-9-80, and MD-90-30 
series airplanes, Model MD-88 airplanes, and C-9 (military) series 
airplanes of the affected design in the worldwide fleet. The FAA 
estimates that 816 airplanes of U.S. registry will be affected by this 
AD.
    The requirement to inspect and spiral wrap the wire bundle, which 
was previously required by AD 95-09-10, continues to be applicable to 
614 Model DC-9-80 series airplanes and Model MD-88 airplanes of U.S. 
registry. This action takes approximately 3 work hours per airplane to 
accomplish, at an average labor rate is of $60 per work hour. Required 
parts cost approximately $5 per airplane. Based on these figures, the 
cost impact of the current requirements of that AD on U.S. operators of 
the affected airplanes is estimated to be $113,950, or $185 per 
airplane. However, in consideration of the compliance time and 
effective date of AD 95-09-10, the FAA assumes that U.S. operators of 
airplanes that are subject to the requirements of that AD have already 
initiated the required actions. Therefore, the requirement to inspect 
and spiral wrap the wire bundle likely adds no new costs associated 
with those airplanes.
    The requirements of this new AD action to inspect and spiral wrap 
the wire bundle are also applicable to approximately 202 Model DC-9, 
MD-9-30, and C-9 (military) series airplanes of U.S. registry. Based on 
the figures discussed above, the new costs imposed by this AD on U.S. 
operators of these airplanes are estimated to be $37,370, or $185 per 
airplane.
    The requirement to reroute the wire bundle that is required by this 
new AD is applicable to all 816 airplanes of U.S. registry. 
Accomplishing this rerouting will take approximately 0.5 work hour per 
airplane, at an average labor rate of $60 per work hour. Required parts 
will cost approximately $5 per airplane. Based on these figures, the 
cost impact on U.S. operators of the new requirements of this AD is 
estimated to be $28,560, or $35 per airplane.
    The cost impact figures discussed above, associated with the new 
requirements of this AD, are based on assumptions that no operator has 
yet accomplished any of those requirements, and that no operator would 
accomplish those actions in the future if this AD were not adopted.
    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 USC 106(g), 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by removing amendment 39-9213 (60 FR 
21977, May 4, 1995), and by adding a new airworthiness directive (AD), 
amendment 39-9565, to read as follows:

96-07-15  McDonnell Douglas: Amendment 39-9565. Docket 95-NM-131-AD. 
Supersedes AD 95-09-10, Amendment 39-9213.

    Applicability: Model DC-9 and DC-9-80 series airplanes, Model 
MD-88 airplanes, and C-9 (military) series airplanes, as listed in 
McDonnell Douglas DC-9 Alert Service Bulletin DC9-24A157, dated 
April 11, 1995; and Model MD-90-30 series airplanes, as listed in 
McDonnell Douglas Alert Service Bulletin MD90-24A001, dated April 
11, 1995; 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 (d) 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 the potential for fire and uncontrolled smoke 
throughout the cockpit due to damaged electrical wiring, accomplish 
the following:
    (a) For Model DC-9-80 series airplanes and Model MD-88 
airplanes: Within 90 days

[[Page 16379]]

after May 19, 1995 (the effective date of AD 95-09-10, amendment 39-
9213), perform a visual inspection to detect chafing of or damage to 
the wire bundle in the overhead switch panel of the cockpit, in 
accordance with McDonnell Douglas Alert Service Bulletin DC9-24A157, 
dated April 11, 1995, or Revision 1, dated November 11, 1995.
    (1) If no chafing or damage is detected, prior to further 
flight, apply spiral wrap to the wire bundle in accordance with the 
alert service bulletin.
    (2) If the wire insulation is chafed, prior to further flight, 
repair it and then apply spiral wrap to the wire bundle in 
accordance with the alert service bulletin.
    (3) If the wire conductor is damaged, prior to further flight, 
splice the wires and then apply spiral wrap to the wire bundle, in 
accordance with the alert service bulletin.
    (b) For Model DC-9, C-9 (military), and MD-90-30 series 
airplanes: Within 6 months after the effective date of this AD, 
perform a visual inspection to detect chafing of or damage to the 
wire bundle in the overhead switch panel of the cockpit, in 
accordance with McDonnell Douglas Alert Service Bulletin DC9-24A157, 
dated April 11, 1995, or Revision 1 dated November 9, 1995 [for 
Model DC-9 and C-9 (military) series airplanes]; or McDonnell 
Douglas Alert Service Bulletin MD90-24A001, dated April 11, 1995 
(for Model MD-90-30 series airplanes); as applicable.
    (1) If no chafing or damage is detected, prior to further 
flight, reroute the wire bundle in the overhead switch panel of the 
cockpit in accordance with either McDonnell Douglas Service Bulletin 
DC9-24-157, dated November 9, 1995 [for Model DC-9 series airplanes 
and C-9 (military) series airplanes], or McDonnell Douglas Service 
Bulletin MD90-24-001, dated November 9, 1995 [for Model MD-90-30 
series airplanes], as applicable; or in accordance with a method 
approved by the Manager, Los Angeles Aircraft Certification Office 
(ACO), FAA, Transport Airplane Directorate.
    (2) If the wire insulation is chafed, prior to further flight, 
repair it in accordance with the applicable alert service bulletin; 
then reroute the wire bundle in the overhead switch panel of the 
cockpit in accordance with either McDonnell Douglas Service Bulletin 
DC9-24-157, dated November 9, 1995 [for Model DC-9 series airplanes 
and C-9 (military) series airplanes], or McDonnell Douglas Service 
Bulletin MD90-24-001, dated November 9, 1995 [for Model MD-90-30 
series airplanes], as applicable; or in accordance with a method 
approved by the Manager, Los Angeles ACO.
    (3) If the wire conductor is damaged, prior to further flight, 
splice the wires in accordance with the applicable alert service 
bulletin; then reroute the wire bundle in the overhead switch panel 
of the cockpit in accordance with either McDonnell Douglas Service 
Bulletin DC9-24-157, dated November 9, 1995 [for Model DC-9 series 
airplanes and C-9 (military) series airplanes], or McDonnell Douglas 
Service Bulletin MD90-24-001, dated November 9, 1995 [for Model MD-
90-30 series airplanes], as applicable; or in accordance with a 
method approved by the Manager, Los Angeles ACO.
    (c) For Model DC-9-80 series airplanes and Model MD-88 
airplanes: Within 6 months after the effective date of this AD, 
reroute the wire bundle in the overhead switch panel of the cockpit 
in accordance with either McDonnell Douglas Service Bulletin DC9-24-
157, dated November 9, 1995 [for Model DC-9 series airplanes and C-9 
(military) series airplanes], or McDonnell Douglas Service Bulletin 
MD90-24-001, dated November 9, 1995 [for Model MD-90-30 series 
airplanes], as applicable; or in accordance with a method approved 
by the Manager, Los Angeles ACO.
    (d)(1) 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, Los Angeles ACO. Operators shall 
submit their requests through an appropriate FAA Principal 
Maintenance Inspector, who may add comments and then send it to the 
Manager, Los Angeles ACO.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Los Angeles ACO.

    (2) Alternative methods of compliance approved in accordance 
with AD 95-09-10, amendment 39-9213, are approved as alternative 
methods of compliance with this AD.
    (e) 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.
    (f) The actions shall be done in accordance with the following 
McDonnell Douglas documents:

------------------------------------------------------------------------
       Service bulletin No.          Revision level           Date      
------------------------------------------------------------------------
Alert Service Bulletin MD90-       (Original)........  April 11, 1995.  
 24A001.                                                                
Service Bulletin MD90-24-001.....  (Original)........  November 9, 1995.
Alert Service Bulletin DC9-24A157  (Original)........  April 11, 1995.  
Alert Service Bulletin DC9-24A157  Revision 1........  November 9, 1995.
Service Bulletin DC9-24-157......  (Original)........  November 9, 1995.
------------------------------------------------------------------------

    The incorporation by reference of McDonnell Douglas Alert 
Service Bulletin DC9-24A157, dated April 11, 1995, was approved 
previously by the Director of the Federal Register in accordance 
with 5 U.S.C. 552(a) and 1 CFR part 51 as of May 19, 1995 (60 FR 
21977, May 4, 1995). The incorporation by reference of the remainder 
of the service documents listed above is 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 McDonnell Douglas Corporation, 
3855 Lakewood Boulevard, Long Beach, California 90846, Attention: 
Technical Publications Business Administration, Department C1-L51 
(2-60). Copies may be inspected at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the 
FAA, Transport Airplane Directorate, Los Angeles Aircraft 
Certification Office, 3960 Paramount Boulevard, Lakewood, 
California; or at the Office of the Federal Register, 800 North 
Capitol Street, NW., suite 700, Washington, DC.
    (g) This amendment becomes effective on May 15, 1996.

    Issued in Renton, Washington, on March 29, 1996.
Bill R. Boxwell,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-8295 Filed 4-12-96; 8:45 am]
BILLING CODE 4910-13-U