AD Amdt-39-9612

[Federal Register Volume 61, Number 91 (Thursday, May 9, 1996)]
[Rules and Regulations]
[Pages 21065-21068]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 96-11408]



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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96-NM-77-AD; Amendment 39-9612; AD 96-10-07]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model MD-11 Series 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to certain McDonnell Douglas Model MD-11 series 
airplanes. This action requires inspections to detect damage of the 
support brackets and clamps of the transfer pipe of the tail tank, and 
of the transfer pipe assembly; and replacement of damaged parts, or 
installation of a doubler, if necessary. This amendment is prompted by 
reports of cracking of the support brackets in the refuel and fuel 
transfer lines of the tail fuel tank and damage to the nylon clamps and 
transfer pipe assembly; such damage is due to flexing of the brackets 
and subsequent contact of the transfer pipe assembly with adjacent 
structure. The actions specified in this AD are intended to prevent 
such cracking and damage, which could result in further damage to the 
transfer pipe assembly and possible fuel leakage.

DATES: Effective May 24, 1996.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of May 24, 1996.
    Comments for inclusion in the Rules Docket must be received on or 
before July 8, 1996.
ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 96-NM-77-AD, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056.
    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 FAA, Transport Airplane Directorate, 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: Raymond Vakili, Aerospace Engineer, 
Airframe Branch, ANM-140L, FAA, Los Angeles Aircraft Certification 
Office, 3960 Paramount Boulevard, Lakewood, California 90712; telephone 
(310) 627-5262; fax (310) 627-5210.

SUPPLEMENTARY INFORMATION: The FAA has received reports of cracking of 
the support brackets in the refuel and fuel transfer lines of the tail 
fuel tank on McDonnell Douglas Model MD-11 series airplanes. In 
addition, the nylon clamps and transfer pipe assembly have been found 
to be damaged. Investigation revealed that this cracking and damage was 
caused by flexing of the brackets during refueling and transfer 
operations of the tail fuel tank. When this flexing occurs, the 
transfer pipe assembly can sustain damage due to contact with adjacent 
structure. Such cracking and damage, if not corrected, would result in 
further damage to the fuel transfer pipe assembly and possible fuel 
leakage.

Explanation of Relevant Service Information

    The FAA has reviewed and approved McDonnell Douglas Alert Service 
Bulletin MD11-28A083, dated March 13, 1996, which describes procedures 
for repetitive visual inspections to detect cracking, bending, or 
stress of the support brackets, and any damage to the clamps of the 
transfer pipe of the tail tank; and replacement of any damaged bracket 
or clamp with a serviceable part. The alert service bulletin also 
describes procedures for repetitive visual inspections to detect damage 
of the transfer pipe assembly of the tail tank; and procedures for 
installation of a doubler on the pipe assembly, or replacement of the 
pipe assembly with a serviceable assembly, if necessary.

Explanation of the Requirements of the Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other McDonnell Douglas Model MD-11 series 
airplanes of the same type design, this AD is being issued to prevent 
cracking of the support brackets in the refuel and fuel transfer lines 
of the tail fuel tank and damage to the nylon clamps and transfer pipe 
assembly, which if not corrected, could result in further damage to the 
transfer pipe assembly and possible fuel leakage. This AD requires 
repetitive visual inspections for cracking, bending, or stress of the 
support brackets, and any damage to the clamps of the transfer pipe of 
the tail tank; and replacement of any damaged bracket or clamp with a 
serviceable part. This AD also requires repetitive visual inspections 
for damage of the transfer pipe assembly of the tail tank; and 
installation of a doubler on the pipe assembly, or replacement of the 
pipe assembly with a serviceable assembly, if necessary. The actions 
are required to be accomplished in accordance with the service bulletin 
described previously.

Interim Action

    This AD is considered to be interim action. The manufacturer has 
advised that it currently is developing a modification that will 
positively address the unsafe condition addressed by this AD. Once this 
modification is developed, approved, and available, the FAA may 
consider additional rulemaking.

Difference Between this Rule and the Relevant Service Information

    Operators should note that the McDonnell Douglas alert service 
bulletin recommends accomplishment of the initial inspection at ``the 
earliest practical maintenance period, but not to exceed 600 flight 
hours from the date of issuance of the alert service bulletin.'' 
However, the FAA has determined that, since maintenance intervals vary 
from operator to operator, and since the time of receipt of the alert 
service bulletin also may vary from operator to operator, the 
compliance time for this AD must be less subjective in order to ensure 
that the actions are accomplished by all affected operators in a timely 
manner. This AD requires compliance within 90 days after the effective 
date of the rule. In developing an appropriate compliance time for this 
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 regularly 
scheduled maintenance intervals for the affected airplanes. In light of 
all of these factors, the FAA finds that a 90-day compliance time for 
accomplishment of the initial inspection is appropriate in that it 
represents the maximum interval of time allowable for affected 
airplanes to continue to operate without compromising safety.
    Operators also should note that the effectivity listing in the 
McDonnell Douglas alert service bulletin includes certain airplanes 
designated as ``Group 2 airplanes.'' The initial visual inspection 
(required by this AD) was

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accomplished and a temporary doubler was installed on these airplanes 
during production. For these airplanes, the alert service bulletin 
suggests an inspection interval of 15 months for accomplishment of the 
visual inspection. The FAA has determined that this inspection interval 
for Group 2 airplanes is appropriate, and is considering additional 
rulemaking action to address the requirements for Group 2 airplanes. 
However, a 15-month compliance time for the planned requirements is 
sufficiently long so that notice and time for prior public comment will 
be practicable.

Determination of Rule's Effective Date

    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for prior 
public comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All 
communications received on or before the closing date for comments will 
be considered, and this rule may be amended in light of the comments 
received. Factual information that supports the commenter's ideas and 
suggestions is extremely helpful in evaluating the effectiveness of the 
AD action and determining whether additional rulemaking action would be 
needed.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the 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 that 
summarizes each FAA-public contact concerned with the substance of this 
AD will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this rule must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 96-NM-77-AD.'' The postcard will be date stamped and 
returned to the commenter.

Regulatory Impact

    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.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and that it is not a ``significant regulatory 
action'' under Executive Order 12866. It has been determined further 
that this action involves an emergency regulation under DOT Regulatory 
Policies and Procedures (44 FR 11034, February 26, 1979). If it is 
determined that this emergency regulation otherwise would be 
significant under DOT Regulatory Policies and Procedures, a final 
regulatory evaluation will be prepared and placed in the Rules Docket. 
A copy of it, if filed, 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 U.S.C. 106(g), 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

96-10-07  McDonnell Douglas: Amendment 39-9612. Docket 96-NM-77-AD.

    Applicability: Model MD-11 series airplanes; specified as Group 
1 airplanes and listed in McDonnell Douglas Alert Service Bulletin 
MD-11-28A083, dated March 13, 1996; 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 (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.
    Note 2: Airplanes specified as Group 2 airplanes and listed in 
McDonnell Douglas Alert Service Bulletin MD-11-28A083, dated March 
13, 1996, are not subject to this AD.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent cracking of the support brackets in the refuel and 
fuel transfer lines of the tail fuel tank and damage to the nylon 
clamps and transfer pipe assembly, which, if not corrected, could 
result in further damage to the transfer pipe assembly and possible 
fuel leakage, accomplish the following:
    (a) Within 90 days after the effective date of this AD, 
accomplish the requirements of paragraphs (a)(1) and (a)(2) of this 
AD in accordance with Paragraph 3. of the Accomplishment 
Instructions of McDonnell Douglas Alert Service Bulletin MD-11-
28A083, dated March 13, 1996.
    (1) Perform a visual inspection for cracking, bending, or stress 
of the support brackets and damage to the nylon clamps of the 
transfer pipe of the tail tank, in accordance with the alert service 
bulletin. If any damaged bracket or clamp is detected, prior to 
further flight, replace it with a serviceable part in accordance 
with the alert service bulletin.
    (2) Perform a visual inspection for chafing and/or denting of 
the transfer pipe assembly of the tail tank, in accordance with the 
alert service bulletin.
    (i) Condition 1. If no damage to the fuel pipe assembly is 
detected, accomplish the requirements of either paragraph 
(a)(2)(i)(A) or (a)(2)(i)(B) of this AD at the times specified in 
that paragraph.
    (A) Option 1. Thereafter, repeat the visual inspections required 
by paragraph (a) of this AD at intervals not to exceed 600 flight 
hours; or
    (B) Option 2. Install a temporary doubler on the fuel pipe 
assembly in accordance with the alert service bulletin and, 
thereafter, repeat the visual inspections required by paragraph (a) 
of this AD at intervals not to exceed 15 months.
    (ii) Condition 2. If damage is found that is within the limits 
specified by the alert service bulletin, prior to further flight, 
install a temporary doubler on the fuel pipe assembly. Thereafter, 
repeat the visual inspections required by paragraph (a) of this AD 
at intervals not to exceed 15 months.
    (iii) Condition 3. If damage is found that is outside the limits 
specified by the alert service bulletin, prior to further flight, 
replace the fuel pipe assembly with a new or

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serviceable assembly; and accomplish the requirements of either 
paragraph (a)(2)(iii)(A) or (a)(2)(iii)(C) of this AD at the time 
specified in that paragraph.
    (A) Option 1. Thereafter, repeat the visual inspections required 
by paragraph (a) of this AD at intervals not to exceed 600 flight 
hours; or
    (B) Option 2. Install a temporary doubler on the fuel pipe 
assembly; and repeat the visual inspections required by paragraph 
(a) of this AD, thereafter, at intervals not to exceed 15 months. 
(Replacement of the fuel pipe assembly with a serviceable pipe 
assembly that has been repaired by welding a doubler in the area of 
potential damage, does not require the installation of a temporary 
doubler.)
    (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 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 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.
    (d) The actions shall be done in accordance with McDonnell 
Douglas Alert Service Bulletin MD-11-28A083, dated March 13, 1996. 
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, 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, 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.
    (e) This amendment becomes effective on May 24, 1996.

    Issued in Renton, Washington, on May 1, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-11408 Filed 5-8-96; 8:45 am]
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