[Federal Register Volume 59, Number 76 (Wednesday, April 20, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-9472]


[[Page Unknown]]

[Federal Register: April 20, 1994]


-----------------------------------------------------------------------


DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 93-NM-110-AD; Amendment 39-8890; AD 94-09-02]

 

Airworthiness Directives; McDonnell Douglas Model DC-9-80 Series 
Airplanes and Model MD-88 Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

-----------------------------------------------------------------------

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 damage of the auxiliary power unit (APU) power 
feeder cable installation, repair of damaged cables, and modification 
of the cable installation. This amendment requires an inspection of 
previously modified airplanes to determine whether a spacer or ``stand 
off'' has been installed, and installation of those items, if 
necessary. This amendment is prompted by reports of generator power 
feeder cables electrically shorting to the airplane structure due to 
chafing. The actions specified by this AD are intended to prevent the 
APU power feeder cable from chafing against adjacent structures, which 
could result in electrical shorting and arcing, and a fire below the 
cabin floor.

DATES: Effective May 20, 1994.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of May 20, 1994.

ADDRESSES: The service information referenced in this AD may be 
obtained from McDonnell Douglas Corporation, P.O. Box 1771, Long Beach, 
California 90801-1771, Attention: Business Unit Manager, Technical 
Publications--Technical Administrative Support, C1-L5B. 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, 3229 East Spring Street, Long Beach, California; 
or at the Office of the Federal Register, 800 North Capitol Street, 
NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Elvin K. Wheeler, Aerospace Engineer, 
Systems and Equipment Branch, ANM-132L, FAA, Transport Airplane 
Directorate, Los Angeles Aircraft Certification Office, 3229 East 
Spring Street, Long Beach, California 90806-2425; telephone (310) 988-
5344; fax (310) 988-5210.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations by superseding AD 88-20-05, amendment 39-6022 (53 
FR 36436, September 20, 1988), which is applicable to McDonnell Douglas 
Model DC-9-80 series airplanes and Model MD-88 airplanes, was published 
in the Federal Register on September 9, 1993 (58 FR 46917). The action 
proposed to continue to require a one-time visual inspection to detect 
damage of the APU power feeder cable support clamp installation, repair 
of damaged cables, and modification of the APU power feeder cable 
installation. The action proposed to add a general visual inspection of 
previously modified airplanes to determine whether a spacer or ``stand 
off'' has been installed between the clamp and the bracket, and 
installation of a spacer or ``stand off,'' if necessary.
    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 proposal.
    One commenter requests that the proposed rule provide ``credit'' 
for operators who have previously accomplished the procedures specified 
in McDonnell Douglas Service Bulletin 24-105, dated August 15, 1989. 
Those procedures ensure the installation of a ``stand off'' between the 
clamp and the bracket in the APU power feeder cable support clamp 
installation. Paragraph (c) of the proposal would require operators to 
inspect for the installation of this item; if it is installed, no 
further action would be required by the proposed AD. The FAA concurs. 
Paragraph (c) has been revised to indicate that McDonnell Douglas 
Service Bulletin 24-105 is considered an acceptable alternative method 
of compliance with that paragraph, and that operators who have 
accomplished the procedures described in that service bulletin are not 
required to re-inspect the subject area.
    This same commenter requests that proposed paragraph (c) be revised 
to clarify the airplanes to which the requirements are applicable. The 
commenter points out that the referenced McDonnell Douglas Service 
Bulletin 24-94, Revision 4, dated June 7, 1993, specifies that the 
applicable airplanes are those listed as ``Groups IV through IX'' in 
that service bulletin, which have not been inspected in accordance with 
that service bulletin, but have been inspected and modified in 
accordance with paragraphs (a) and (b) of the existing AD. The FAA 
concurs that this clarification is appropriate. Therefore, paragraph 
(c) of the final rule has been revised accordingly.
    One commenter notes that paragraph (c)(2) of the proposed AD calls 
out a specific spacer, part number NAS43DD3-32, that must be installed 
(under a clamp used to secure the APU generator feeders) in accordance 
with McDonnell Douglas Service Bulletin 24-94, Revision 4. The 
commenter points out that Table III (page 24) of that service bulletin 
refers to Service Rework Drawing SR09240004, sheet 7.7, for 
installation of the spacer; however, the revision of that drawing that 
the commenter has does not provide positive identification (i.e., no 
part number) of any spacer to be installed. The commenter requests that 
the FAA require that the service information correctly identify, on the 
installation drawing, the part number of the spacer that should be 
used. The FAA concurs. Since issuance of the notice, the FAA has 
reviewed and approved Revision G of the referenced drawing, which does 
call out the part number of the correct spacer that is to be used. No 
change to the final rule is necessary because of this, however. -
    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 390 Model DC-9 series airplanes and Model 
MD-88 airplanes of the affected design in the worldwide fleet. The FAA 
estimates that 241 airplanes of U.S. registry will be affected by this 
AD, that it will take approximately 34 work hours per airplane to 
accomplish the required actions, and that the average labor rate is $55 
per work hour. Based on these figures, the total cost impact of the AD 
on U.S. operators is estimated to be $450,670, or $1,870 per airplane.
    The total cost impact figure discussed above is 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.
    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 14 CFR part 
39 of the Federal Aviation Regulations as follows:

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by removing amendment 39-6022 (53 FR 
36436, September 20, 1988), and by adding a new airworthiness directive 
(AD), amendment 39-8890, to read as follows:

94-09-02 McDonnell Douglas: Amendment 39-8890. Docket 93-NM-110-AD. 
Supersedes AD 88-20-05, Amendment 39-6022.

    Applicability: Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 
(MD-83), and DC-9-87 (MD-87) series airplanes, and Model MD-88 
airplanes; as listed in McDonnell Douglas MD-80 Service Bulletin 24-
94, Revision 1, dated May 28, 1987, and McDonnell Douglas Model MD-
80 Service Bulletin 24-100, dated March 30, 1988; certificated in 
any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent the APU power feeder cable from chafing against 
adjacent structures, which could result in electrical shorting and 
arcing, and a fire below the cabin floor, accomplish the following:

    Note 1: Paragraphs (a) and (b) of this AD merely restate the 
requirements of paragraphs (a) and (b) of AD 88-20-05, Amendment 39-
6602. As allowed by the phrase, ``unless accomplished previously,'' 
if those requirements of AD 88-20-05 have already been accomplished, 
this AD does not require that those actions be repeated.

    (a) For airplanes listed in McDonnell Douglas MD-80 Service 
Bulletin 24-94, Revision 1, dated May 28, 1987: Within 12 months 
after October 31, 1988 (the effective date of AD 88-20-05, Amendment 
39-6022), perform a visual inspection to detect damage of the 
auxiliary power unit (APU) power feeder cable support clamp 
installation; and prior to further flight, repair the damaged cable, 
and modify the APU power feeder cable installation; in accordance 
with McDonnell Douglas MD-80 Service Bulletin 24-94, Revision 1, 
dated May 28, 1987.
    (b) For airplanes listed in McDonnell Douglas MD-80 Service 
Bulletin 24-100, dated March 30, 1988: Within 12 months after 
October 31, 1988 (the effective date of AD 88-20-05, Amendment 93-
6022), modify the APU power feeder cable support clamp installation 
in accordance with McDonnell Douglas MD-80 Service Bulletin 24-100, 
dated March 30, 1988.
    (c) For airplanes identified as Groups IV through IX in 
McDonnell Douglas Service Bulletin 24-94, Revision 4, dated June 7, 
1993, on which the inspection and modification requirements of 
paragraphs (a) and (b) of this AD have been accomplished prior to 
the effective date of this AD, and which have not been inspected in 
accordance with McDonnell Douglas MD-80 Service Bulletin 24-94, 
Revision 4, dated June 7, 1993: Within 12 months after the effective 
date of this AD, perform a general visual inspection of the APU 
power feeder cable support clamp installation to determine whether a 
spacer or ``stand off'' has been installed between the clamp and the 
bracket.

    Note 2: Accomplishment of the procedures specified in McDonnell 
Douglas Service Bulletin 24-105, dated August 15, 1989, is 
considered an acceptable alternative method of compliance with this 
paragraph. Operators who have accomplished those procedures prior to 
the effective date of this AD are not required to re-inspect the 
subject area.

    (1) If a spacer or ``stand off'' has been installed, no further 
action is required by this AD.
    (2) If a spacer or ``stand off'' has not been installed, prior 
to further flight, install a new or serviceable spacer or ``stand 
off,'' part number (P/N) NAS43DD3-32, in accordance with McDonnell 
Douglas MD-80 Service Bulletin 24-94, Revision 4, dated June 7, 
1993.
    (d) 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, 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, Los Angeles ACO.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Los Angeles ACO.
    Note 4: Alternative methods of compliance approved for 
paragraphs (a) and (b) of AD 88-20-05, Amendment 39-6602, continue 
to be considered acceptable for this AD.

    (e) Special flight permits may be issued in accordance with 
Federal Aviation Regulations (FAR) 21.197 and 21.199 to operate the 
airplane to a location where the requirements of this AD can be 
accomplished.
    (f) The installation shall be done in accordance with McDonnell 
Douglas MD-80 Service Bulletin 24-94, Revision 4, dated June 7, 
1993. 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 McDonnell Douglas Corporation, 
P.O. Box 1771, Long Beach, California 90801-1771, Attention: 
Business Unit Manager, Technical Publications--Technical 
Administrative Support, C1-L5B. Copies may be inspected at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington; or at the FAA, Los Angeles Aircraft Certification 
Office, 3229 East Spring Street, Long Beach, 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 20, 1994.

    Issued in Renton, Washington, on April 14, 1994.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-9472 Filed 4-19-94; 8:45 am]
BILLING CODE 4910-13-U