[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
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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]
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