[Federal Register Volume 61, Number 132 (Tuesday, July 9, 1996)]
[Rules and Regulations]
[Pages 35946-35949]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-17217]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 96-NM-133-AD; Amendment 39-9691; AD 96-14-07]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model MD-11 and MD-
11F Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD), applicable to certain McDonnell Douglas Model MD-11 and MD-11F 
series airplanes, that currently requires repetitive inspections of the 
tail tank fuel pipe assembly and the associated mounting brackets in 
the aft fuselage compartment, and follow-on actions, if necessary. That 
AD also provides for an optional terminating modification for the 
repetitive inspections. This amendment deletes the optional terminating 
modification, and expands the applicability of the existing AD to 
include additional airplanes. This amendment is prompted by reports of 
cracking or bending of the fuel pipe mounting support and/or attaching 
bracket in the aft fuselage compartment due to a fuel pressure surge 
that caused repetitive loading of this area. The actions specified in 
this AD are intended to prevent such cracking/bending, which could 
expose the fuel pipe coupling O-ring. An exposed O-ring could lose its 
sealing effect and could allow a fuel leak in the aft fuselage 
compartment, which may result in a possible in-flight or ground fire.

DATES: Effective July 24, 1996.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of July 24, 1996.
    Comments for inclusion in the Rules Docket must be received on or 
before September 9, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 96-NM-133-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, 
Propulsion 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: On November 4, 1991, the FAA issued AD 91-
24-09, amendment 39-8095 (56 FR 61364, December 3, 1991), applicable to 
certain McDonnell Douglas Model MD-11 and MD-11F series airplanes. That 
AD requires repetitive visual inspections of the tail tank fuel pipe 
assembly and the associated mounting brackets located in the aft 
fuselage compartment to verify the correct position of the pipe flange 
and to detect damaged brackets. It also requires various follow-on 
actions, if any discrepancy is detected. That AD also provides for an 
optional terminating modification for the repetitive inspections. That 
action was prompted by a report of an uncontained fuel leak in the aft 
fuselage compartment on an in-service airplane, which was the result of 
migration of the tail tank fuel pipe assembly, and consequent exposure 
of the O-ring that provides the seal between the pipe assembly and the 
coupling shroud assembly. The actions required by that AD are intended 
to prevent a fuel leak in the aft fuselage compartment area, and the 
possibility of an in-flight or ground fire.

Actions Since Issuance of Previous Rule

    Since the issuance of that AD, the FAA has received several reports 
of cracking or bending of the fuel pipe mounting support and/or 
attaching bracket at station Y=2033.750 in the aft

[[Page 35947]]

fuselage compartment on McDonnell Douglas Model MD-11 series airplanes. 
A section of the fuel pipe assembly and support bracket of some of 
these airplanes had been replaced in accordance with the optional 
terminating modification specified in AD 91-24-09. Additionally, this 
replacement had been accomplished during production on certain other 
airplanes on which these incidents occurred.
    Investigation revealed that a fuel pressure surge during transfer 
of the tail tank fuel caused repetitive loading of the fuel pipe 
mounting support and/or attaching bracket, which resulted in the 
subject cracking/bending. Although none of the reported events have 
resulted in a fuel leak in the aft fuselage compartment, the FAA has 
determined that severe deformation of the bracket could allow the pipe 
to migrate, which could also expose the O-ring that provides the seal 
between the fuel pipe and coupling. If the O-ring is exposed, it could 
lose its sealing effect, and allow a fuel leak in the aft fuselage 
compartment, which could result in a possible in-flight or ground fire.
    In light of these recent incidents, which are similar to the 
incident that prompted the issuance of AD 91-24-09, the FAA finds that 
the optional and on-condition terminating modifications (i.e., 
replacement of a section of the fuel pipe assembly and support bracket, 
an FAA-approved repair procedure, and replacement of the shroud 
assembly) specified in AD 91-24-09 do not adequately preclude the 
addressed unsafe condition identified as in-flight or ground fire. 
Therefore, the FAA finds that repetitive visual inspections to detect 
discrepancies (i.e., cracks, or deformation) of the fuel pipe of the 
fuel transfer system of the tail tank and associated mounting bracket 
located in the aft fuselage compartment, and to verify the correct 
position of the fuel pipe flange are necessary. These actions will 
ensure that the unsafe condition presented by fuel surge during 
transfer of tail tank fuel is corrected, and provide an acceptable 
level of safety.

Explanation of Relevant Service Information

    The FAA has reviewed and approved McDonnell Douglas Alert Service 
Bulletin MD11-28A082, dated May 14, 1996. The alert service bulletin 
describes procedures for repetitive visual inspections to detect 
discrepancies (i.e., cracks, or deformation) of the fuel pipe of the 
fuel transfer system of the tail tank and associated mounting bracket 
located in the aft fuselage compartment; and to verify the correct 
position of the fuel pipe flange, and various follow-on actions. These 
follow-on actions include replacing the O-ring, repositioning the tail 
tank fuel pipe, and installing a temporary phenolic support block 
assembly. Installation of a phenolic support block assembly between the 
tail tank fuel pipe and adjoining structure as a temporary restraint 
will minimize the possibility of migration of the tail tank fuel pipe.
    In addition, the visual inspections and certain of the follow-on 
actions of Alert Service Bulletin MD11-28A082 are essentially identical 
to those described in McDonnell Douglas MD-11 Alert Service Bulletin 
A28-22, Revision 4, dated September 16, 1991 (which was referenced in 
AD 91-24-09). However, the effectivity listing of Alert Service 
Bulletin MD11-28A082 includes additional airplanes that were not 
included in the effectivity listing of Alert Service Bulletin A28-22. 
These additional airplanes have been found to be subject to the 
addressed unsafe condition.

Explanation of Requirements of Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other airplanes of this same type design, this AD 
supersedes AD 91-24-09 to require repetitive visual inspections to 
detect discrepancies (i.e., cracks or deformation) of the fuel pipe of 
the fuel transfer system of the tail tank and associated mounting 
bracket located in the aft fuselage compartment and to verify the 
correct position of the fuel pipe flange, and various follow-on 
actions. This AD also expands the applicability of the existing AD to 
include additional airplanes.
    This 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.

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-133-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

[[Page 35948]]

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 removing amendment 39-8095 (56 FR 
61364, December 3, 1991), and by adding a new airworthiness directive 
(AD), amendment 39-9691, to read as follows:

96-14-07 McDonnell Douglas: Amendment 39-9691, Docket 96-NM-133-AD. 
Supersedes AD 91-24-09, Amendment 39-8095.

    Applicability: Model MD-11 and MD-11F series airplanes, 
manufacturer's fuselage numbers 0447 through 0599 inclusive; 
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 (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 the possibility of an in-flight or ground fire due to 
fuel leaking from the fuel pipe coupling, accomplish the following:
    (a) Perform a visual inspection to detect discrepancies (i.e., 
cracks or deformation) of the fuel pipe of the fuel transfer system 
of the tail tank and associated mounting bracket located in the aft 
fuselage compartment; and to verify the correct position of the fuel 
pipe flange, in accordance with McDonnell Douglas Alert Service 
Bulletin MD11-28A082, dated May 14, 1996; at the time specified in 
paragraph (a)(1) or (a)(2) of this AD, as applicable.
    (1) For airplanes on which the modification specified in 
McDonnell Douglas Service Bulletin 28-22, dated September 24, 1991, 
has been accomplished; or that have been repaired in accordance with 
an FAA-approved repair procedure, as specified in paragraph (a)(3) 
of AD 91-24-09, amendment 39-8095; or on which the shroud assembly 
has been replaced with a serviceable part: Prior to the accumulation 
of 600 flight hours, or within 60 days after the effective date of 
this AD, whichever occurs later.
    (2) For airplanes on which the modification specified in 
McDonnell Douglas Service Bulletin 28-22, dated September 24, 1991, 
has not been accomplished: Prior to the accumulation of 600 flight 
hours, or within 60 days since accomplishment of the last visual 
inspection in accordance with AD 91-24-09, whichever occurs first.
    (b) CONDITION 1. If no discrepancy is detected during any visual 
inspection required by paragraph (a) of this AD, accomplish either 
paragraph (b)(1) or (b)(2) of this AD.
    (1) OPTION 1. Repeat the visual inspection required by paragraph 
(a) of this AD thereafter at intervals not to exceed 600 flight 
hours or 60 days, whichever occurs later. Or
    (2) OPTION 2. Prior to further flight, install a temporary 
phenolic support block assembly, shim, clamp, and bracket between 
the tail tank fuel pipe and station Y=2033.750 bulkhead, in 
accordance with Condition 1, Option 2, of McDonnell Douglas Alert 
Service Bulletin MD11-28A082, dated May 14, 1996. Within 6 months 
after accomplishment of this installation, perform a one-time 
inspection to verify the correct position of the temporary support 
block assembly installation in accordance with Figure 2 (Sheet 2 of 
3) of the alert service bulletin.
    (i) If the assembly is found to be positioned properly, repeat 
the verification of the correct position of the fuel pipe flange, as 
specified in paragraph (a) of this AD, thereafter at intervals not 
to exceed 15 months.
    (ii) If the assembly is found to be improperly positioned, prior 
to further flight, reposition the fuel pipe in accordance with 
Figure 2 (Sheet 2 of 3) of the alert service bulletin. Repeat the 
verification of the correct position of the fuel pipe flange, as 
specified in paragraph (a) of this AD, thereafter at intervals not 
to exceed 15 months.
    (c) CONDITION 2. If any discrepancy is detected, and the fuel 
pipe is found to be improperly positioned, but the O-ring is not 
exposed, during any visual inspection required by paragraph (a) of 
this AD, prior to further flight, accomplish either paragraph (c)(1) 
or (c)(2) of this AD.
    (1) OPTION 1. Repeat the visual inspection in paragraph (a) of 
this AD thereafter at intervals not to exceed 600 flight hours or 60 
days, whichever occurs later. Or
    (2) OPTION 2. Prior to further flight, install a temporary 
phenolic support block assembly, shim, clamp, and bracket between 
the tail tank fuel pipe and station Y=2033.750 bulkhead; and 
reposition the fuel pipe assembly, as applicable; in accordance with 
Condition 2, Option 2, of McDonnell Douglas Alert Service Bulletin 
MD11-28A082, dated May 14, 1996. Within 6 months after 
accomplishment of this installation, perform a one-time inspection 
to verify the correct position of the temporary support block 
assembly installation in accordance with Figure 2 (Sheet 2 of 3) of 
the alert service bulletin.
    (i) If the assembly is found to be positioned properly, repeat 
the verification of the correct position of the fuel pipe flange, as 
specified in paragraph (a) of this AD, thereafter at intervals not 
to exceed 15 months.
    (ii) If the assembly is found to be improperly positioned, prior 
to further flight, reposition the fuel pipe in accordance with 
Figure 2 (Sheet 2 of 3) of the alert service bulletin. Repeat the 
verification of the correct position of the fuel pipe flange, as 
specified in paragraph (a) of this AD, thereafter at intervals not 
to exceed 15 months.
    (d) CONDITION 3. If any discrepancy is detected, and the fuel 
pipe is found to be improperly positioned, and the O-ring is 
exposed, during any visual inspection required by paragraph (a) of 
this AD, prior to further flight, replace the O-ring with a new O-
ring, and install a temporary phenolic support block assembly, shim, 
clamp, and bracket between the tail tank fuel pipe and station 
Y=2033.750 bulkhead, in accordance with McDonnell Douglas Alert 
Service Bulletin MD11-28A082, dated May 14, 1996. Within 6 months 
after accomplishment of the replacement and installation, perform a 
one-time inspection to verify the correct position of the temporary 
support block assembly installation in accordance with Figure 2 
(Sheet 2 of 3) of the alert service bulletin.
    (1) If the assembly is found to be positioned properly, repeat 
the verification of the correct position of the fuel pipe flange, as 
specified in paragraph (a) of this AD, thereafter at intervals not 
to exceed 15 months.
    (2) If the assembly is found to be improperly positioned, prior 
to further flight, reposition the fuel pipe in accordance with 
Figure 2 (Sheet 2 of 3) of the alert service bulletin. Repeat the 
verification of the correct position of the fuel pipe flange, as 
specified in paragraph (a) of this AD, thereafter at intervals not 
to exceed 15 months.
    (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.

    (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.
    (g) The actions shall be done in accordance with McDonnell 
Douglas Alert Service

[[Page 35949]]

Bulletin MD11-28A082, dated May 14, 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.
    (h) This amendment becomes effective on July 24, 1996.
    Issued in Renton, Washington, on July 1, 1996.
S.R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-17217 Filed 7-8-96; 8:45 am]
BILLING CODE 4910-13-P