[Federal Register Volume 65, Number 11 (Tuesday, January 18, 2000)]
[Proposed Rules]
[Pages 2555-2557]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-1118]


========================================================================
Proposed Rules
                                                Federal Register
________________________________________________________________________

This section of the FEDERAL REGISTER contains notices to the public of 
the proposed issuance of rules and regulations. The purpose of these 
notices is to give interested persons an opportunity to participate in 
the rule making prior to the adoption of the final rules.

========================================================================


Federal Register / Vol. 65, No. 11 / Tuesday, January 18, 2000 / 
Proposed Rules

[[Page 2555]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-227-AD]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model DC-9-81 (MD-
81), DC-9-82 (MD-82), DC-9-83 (MD-83), and DC-9-87 (MD-87), Model MD-88 
Airplanes, and Model MD-90-30 Series Airplanes

AGENCY:  Federal Aviation Administration, DOT.

ACTION:  Notice of proposed rulemaking (NPRM).

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

SUMMARY:  This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to certain McDonnell Douglas Model 
DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), and DC-9-87 (MD-87) 
series airplanes, Model MD-88 airplanes, and Model MD-90-30 series 
airplanes. This proposal would require installation of a pipe support 
and clamps on the hydraulic lines in the aft fuselage; replacement of 
the hydraulic pipe assembly in the aft fuselage with a new pipe 
assembly; and installation of drain tube assemblies and diverter 
assemblies in the area of the auxiliary power unit (APU) inlet; as 
applicable. This proposal is prompted by reports of smoke and odor in 
the passenger cabin and cockpit due to hydraulic fluid leaking into the 
APU inlet, and subsequently, into the air conditioning system. The 
actions specified by the proposed AD are intended to prevent such 
hydraulic fluid leakage due to fatigue vibration and cracking in the 
flared radius of a hydraulic pipe in the aft fuselage, which could 
result in smoke and odors in the passenger cabin or cockpit.

DATES:  Comments must be received by March 3, 2000.

ADDRESSES:  Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 99-NM-227-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.
    The service information referenced in the proposed rule may be 
obtained from Boeing Commercial Aircraft Group, Long Beach Division, 
3855 Lakewood Boulevard, Long Beach, California 90846, Attention: 
Technical Publications Business Administration, Dept. C1-L51 (2-60). 
This information may be examined 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.

FOR FURTHER INFORMATION CONTACT:  Albert Lam, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130L, FAA, Transport Airplane 
Directorate, Los Angeles Aircraft Certification Office, 3960 Paramount 
Boulevard, Lakewood, California 90712-4137; telephone (562) 627-5346; 
fax (562) 627-5210.

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 notice may be changed in 
light of the comments received.
    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 notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 99-NM-227-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. 99-NM-227-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received several reports of smoke and odor in the 
passenger cabin on McDonnell Douglas Model DC-9-82 (MD-82) series 
airplanes due to failure of a hydraulic pipe in the aft fuselage 
accessory compartment. Investigation revealed that hydraulic fluids 
leaked into the bilge area of the tailcone and out of the existing 
drains and were ingested into the air intake area of the auxiliary 
power unit (APU), and subsequently, into the air conditioning system. 
Further investigation revealed that the leaking fluid was due to 
fatigue vibration and cracking in the flared radius of a hydraulic pipe 
in the aft fuselage. This condition, if not corrected, could result in 
smoke and odors in the passenger cabin or cockpit.
    The subject hydraulic pipe assembly on McDonnell Douglas Model DC-
9-81 (MD-81), DC-9-83 (MD-83), and DC-9-87 (MD-87) series airplanes, 
Model MD-88 airplanes, and Model DC-90-30 series airplanes is similar 
to those on the affected Model DC-9-82 (MD-82) airplanes. Therefore, 
all of these airplanes may be subject to the same unsafe condition.

Explanation of Relevant Service Information

    The FAA has reviewed and approved McDonnell Douglas Service 
Bulletin MD80-29-056, dated June 18, 1996 [for Model DC-9-81 (MD-81), 
DC-9-82 (MD-82), DC-9-83 (MD-83), and DC-9-87 (MD-87) series 
airplanes], which describes procedures for installation of a pipe 
support and clamps on the hydraulic lines in the aft fuselage.
    The FAA also has reviewed and approved McDonnell Douglas Service

[[Page 2556]]

Bulletin MD80-29-062, Revision 01, dated August 3, 1999 [for Model DC-
9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), and DC9-87 (MD-87) 
series airplanes, and Model MD-88 airplanes], which describes 
procedures for replacement of the hydraulic pipe assembly in the aft 
fuselage with a new pipe assembly having a greater wall thickness.
    In addition, the FAA has reviewed and approved McDonnell Douglas 
Service Bulletins MD80-53-286, dated September 3, 1999 [for 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], and MD90-53-018, dated 
September 3, 1999 (for Model MD-90-30 series airplanes), which describe 
procedures for installation of drain tube assemblies and diverter 
assemblies in the area of the APU inlet.
    Accomplishment of the actions specified in the service bulletins 
listed above 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 bulletins described previously.

Differences Between Proposed Rule and Service Bulletins

    Operators should note that, although McDonnell Douglas Service 
Bulletins MD80-29-056, dated June 18, 1996; MD80-53-286, dated 
September 3, 1999; and MD90-53-018, dated September 3, 1999; recommend 
accomplishing the modifications at the earliest practical maintenance 
period (after the release of the service bulletin), the FAA has 
determined that such an interval would not address the identified 
unsafe condition in a timely manner. In developing an appropriate 
compliance time for this proposed AD, the FAA considered not only the 
manufacturer's recommendation, but the degree of urgency associated 
with addressing the subject unsafe condition, the average utilization 
of the affected fleet, and the time necessary to perform the 
modifications. In light of all of these factors, the FAA finds that an 
18-month compliance time for initiating the proposed actions to be 
warranted, in that it represents an appropriate interval of time 
allowable for affected airplanes to continue to operate without 
compromising safety.

Cost Impact

    There are approximately 1,126 airplanes of the affected design in 
the worldwide fleet. The FAA estimates that 634 airplanes of U.S. 
registry would be affected by this proposed AD.
    It would take approximately 2 work hours per airplane [for 512 
Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), and DC-9-87 
(MD-87) series airplanes] to accomplish the proposed installation of 
the pipe support and clamps, at an average labor rate of $60 per work 
hour. Required parts would cost approximately $226 per airplane. Based 
on these figures, the cost impact of this installation proposed by AD 
on U.S. operators is estimated to be $177,152, or $346 per airplane.
    It would take approximately 2 work hours per airplane [for 634 
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] to accomplish the 
proposed replacement, at an average labor rate of $60 per work hour. 
Required parts would cost approximately $520 per airplane. Based on 
these figures, the cost impact of this replacement proposed by this AD 
on U.S. operators is estimated to be $405,760, or $640 per airplane.
    It would take approximately 14 work hours per airplane (for 22 
Model MD-90-30 series airplanes) to accomplish the proposed 
installation of drain tube assemblies and diverter assemblies, at an 
average labor rate of $60 per work hour. Required parts would cost 
approximately $4,503 per airplane. Based on these figures, the cost 
impact of the proposed AD on U.S. operators is estimated to be 
$117,546, or $5,343 per airplane.
    The cost impact figures discussed above are 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 AD were not adopted.

Regulatory Impact

    The regulations proposed herein would 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 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    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:

McDonnell Douglas: Docket 99-NM-227-AD.

    Applicability: Models and series of airplanes as listed in the 
applicable McDonnell Douglas service bulletin(s) specified in Table 1 
of this AD, certificated in any category.

                                 Table 1
------------------------------------------------------------------------
                                              McDonnell Douglas service
             Model of airplane                       bulletin(s)
------------------------------------------------------------------------
DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83   MD80-29-056, dated June 18,
 (MD-83), and DC-9-87 (MD-87) series         1996; MD80-29-062, Revision
 airplanes.                                  01, dated August 3, 1999;
                                             and MD80-53-286, dated
                                             September 3, 1999.
MD-88 airplanes...........................  MD80-29-062, Revision 01,
                                             dated August 3, 1999 and
                                             MD80-53-286, dated
                                             September 3, 1999.
MD-90-30 series airplanes.................  MD90-53-018, dated September
                                             3, 1999.
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[[Page 2557]]

    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 (e) 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 hydraulic fluid leakage into the auxiliary power unit 
(APU) inlet due to fatigue vibration and cracking in the flared radius 
of a hydraulic pipe in the aft fuselage, which could result in smoke 
and odors in the passenger cabin or cockpit; accomplish the following:

Installation a Pipe Support and Clamps

    (a) For Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), 
and DC-9-87 (MD-87) series airplanes, as listed in McDonnell Douglas 
Service Bulletin
    MD80-29-056, dated June 18, 1996: Within 18 months after the 
effective date of this AD, install a pipe support and clamps on the 
hydraulic lines in the aft fuselage in accordance with the service 
bulletin.

Replacement of the Hydraulic Pipe Assembly

    (b) For 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 McDonnell Douglas Service Bulletin MD80-29-062, Revision 01, 
dated August 3, 1999: Within 18 months after the effective date of 
this AD, replace the hydraulic pipe assembly in the aft fuselage 
with a new pipe assembly having a greater wall thickness, in 
accordance with the service bulletin. Except for Model MD-88 
airplanes that have been modified in accordance with McDonnell 
Douglas MD-80 Service Bulletin 29-54, dated February 2, 1993, or 
Revision 2, dated December 17, 1993, the requirements of this 
paragraph must be accomplished concurrently with the requirements of 
paragraph (a) of this AD

Installation of Drain Tube Assemblies and Diverter Assemblies

    (c) For Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), 
and DC-9-87 (MD-87) series airplanes, as listed in McDonnell Douglas 
Service Bulletin MD80-53-286, dated September 3, 1999; and Model MD-
9-30 series airplanes, as listed in McDonnell Douglas Service 
Bulletin MD90-53-018, dated September 3, 1999: Within 18 months 
after the effective date of this AD, install drain tube assemblies 
and diverter assemblies in the area of the APU inlet, in accordance 
with the applicable service bulletin.

Spares

    (d) As of the effective date of this AD, no person shall install 
a hydraulic pipe assembly, part number 7936907-603, on any airplane.

Alternative Methods of Compliance

    (e) 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 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, 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.

Special Flight Permits

    (f) 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.

    Issued in Renton, Washington, on January 11, 2000.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-1118 Filed 1-14-00; 8:45 am]
BILLING CODE 4910-13-U