[Federal Register Volume 64, Number 34 (Monday, February 22, 1999)]
[Proposed Rules]
[Pages 8530-8532]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-4216]


 ========================================================================
 Proposed Rules
                                                 Federal Register
 ________________________________________________________________________
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 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. 64, No. 34 / Monday, February 22, 1999 / 
Proposed Rules  

[[Page 8530]]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-05-AD]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to certain McDonnell Douglas Model 
DC-9-80 series airplanes and Model MD-88 airplanes. This proposal would 
require a one-time visual inspection to determine whether self-aligning 
nuts are installed at certain locations of the aft pressure bulkhead 
tee; and corrective actions, if necessary. This proposal is prompted by 
reports of failures of certain Hi-Lok pin fasteners of the aft pressure 
bulkhead tee due to installation of non-self-aligning nuts. The actions 
specified by the proposed AD are intended to prevent failure of certain 
Hi-Lok pin fasteners and subsequent gouging of the aft pressure 
bulkhead tee, which could result in fatigue cracking and reduced 
structural integrity of the airplane.

DATES: Comments must be received by April 8, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 99-NM-05-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 The Boeing Company, Douglas Products 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: Carl Fountain, Aerospace Engineer, 
Airframe Branch, ANM-120L, FAA, Transport Airplane Directorate, Los 
Angeles Aircraft Certification Office, 3960 Paramount Boulevard, 
Lakewood, California 90712-4137; telephone (562) 627-5222; 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-05-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-05-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received reports of failures of certain Hi-Lok pin 
fasteners of the aft pressure bulkhead tee on certain McDonnell Douglas 
Model DC-9-80 series airplanes and Model MD-88 airplanes. These failed 
Hi-Lok pin fasteners were found during the first 10,000-flight-hour 
special surveillance inspection. The failures are attributed to the 
installation of non-self-aligning nuts. Investigation revealed that, 
certain Hi-Lok pins were installed through a tapered surface on the 
pressure bulkhead tee, and were attached to fasteners without self-
aligning nuts. The nuts became loose and allowed the pins to gouge the 
aft pressure bulkhead tee. Loose or failed fasteners and subsequent 
gouging, if not detected and corrected, could result in fatigue 
cracking and reduced structural integrity of the airplane.

Explanation of Relevant Service Information

    The FAA has reviewed and approved McDonnell Douglas Service 
Bulletin MD80-53-201, Revision 02, dated July 20, 1998, which describes 
procedures for a one-time visual inspection to determine whether self-
aligning nuts are installed at certain locations of the aft pressure 
bulkhead tee; and corrective actions, if necessary. The corrective 
actions involve removal of any non-self-aligning nut; a visual 
inspection to detect gouges in the aft pressure bulkhead tee; repair of 
any gouges that are found to be within the specified limits; and 
installation of new self-aligning nuts. Accomplishment of the actions 
specified in the service bulletin 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 bulletin

[[Page 8531]]

described previously, except as discussed below.

Differences Between Proposed Rule and Service Bulletin

    Operators should note that the service bulletin recommends that the 
inspection to determine whether self-aligning nuts are installed be 
performed at the operator's earliest practical maintenance period, and 
that certain non-self-aligning nuts be replaced when the engines have 
been removed for maintenance. However, the FAA has determined that such 
interpretive compliance times would not address the identified unsafe 
condition in a timely manner. In developing appropriate compliance 
times 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, the accessibility of the area to be replaced, 
and the time necessary to accomplish the replacement (approximately 8 
hours). In light of all of these factors, the FAA finds that inspecting 
for non-self-aligning nuts within a 24-month compliance time and 
replacing any non self-aligning nut prior to further flight; to be 
warranted, in that it represents an appropriate interval of time 
allowable for affected airplanes to continue to operate without 
compromising safety.
    Operators also should note that, although the service bulletin 
specifies that the manufacturer may be contacted for disposition of 
certain gouging repair conditions, this proposal would require the 
repair of those conditions to be accomplished in accordance with a 
method approved by the FAA.

Cost Impact

    There are approximately 1,042 airplanes of the affected design in 
the worldwide fleet. The FAA estimates that 695 airplanes of U.S. 
registry would be affected by this proposed AD, and that it would take 
approximately 1 work hour per airplane to accomplish the proposed 
inspection, at an average labor rate of $60 per work hour. Based on 
these figures, the cost impact of the proposed inspection by this AD on 
U.S. operators is estimated to be $41,700, or $60 per airplane.
    The cost impact figure discussed above is 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-05-AD.

    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 Service Bulletin MD80-53-
201, Revision 02, dated July 20, 1998; 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.
    To prevent failure of certain Hi-Lok pin fasteners and 
subsequent gouging of the aft pressure bulkhead tee, which could 
result in fatigue cracking and reduced structural integrity of the 
airplane, accomplish the following:
    (a) Within 24 months after the effective date of this AD, 
perform a one-time visual inspection to determine whether self-
aligning nuts are installed at certain locations of the aft pressure 
bulkhead tee, in accordance with McDonnell Douglas Service Bulletin 
MD80-53-201, Revision 02, dated July 20, 1998.
    (1) If all nuts installed are self-aligning, no further action 
is required by this AD.
    (2) If any nut is determined to be non-self-aligning, prior to 
further flight, remove the existing nut and perform a one-time 
visual inspection to detect gouges in the aft pressure bulkhead tee 
on station Y=1338.000, in accordance with the service bulletin.
    (i) If no gouge is detected, prior to further flight, install 
new self-aligning nuts in accordance with the service bulletin.
    (ii) If any gouge is detected that is within the repair limits 
specified in the service bulletin, prior to further flight, repair 
the gouge and install new self-aligning nuts in accordance with the 
service bulletin.
    (iii) If any gouge is detected that is outside the repair limits 
specified in the service bulletin, prior to further flight, repair 
in accordance with a method approved by the Manager, Los Angeles 
Aircraft Certification Office (ACO), FAA, Transport Airplane 
Directorate.

    Note 2: Inspections, repairs, or replacements that have been 
accomplished prior to the effective date of this AD, in accordance 
with McDonnell Douglas Service Bulletin MD80-53-201, dated July 6, 
1988, or Revision 1, dated March 22, 1991, are considered acceptable 
for compliance with the applicable action specified by 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, 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 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Los Angeles 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.


[[Page 8532]]


    Issued in Renton, Washington, on February 12, 1999.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-4216 Filed 2-19-99; 8:45 am]
BILLING CODE 4910-13-U