[Federal Register Volume 61, Number 225 (Wednesday, November 20, 1996)]
[Proposed Rules]
[Pages 59036-59038]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-29607]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 96-NM-218-AD]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the supersedure of an existing 
airworthiness directive (AD), applicable to certain McDonnell Douglas 
Model MD-11 and MD-11F series airplanes, that currently requires, among 
other things, repetitive visual inspections to detect discrepancies of 
the fuel pipe of the fuel transfer system of the tail tank and 
associated mounting bracket located in the aft fuselage compartment. 
That AD was 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. This action would add a requirement to install a 
restraint on the tail tank fuel pipe, which would terminate the 
repetitive visual inspections. The actions specified by the proposed 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 would present a fire hazard.

DATES: Comments must be received by December 30, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 96-NM-218-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 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.

FOR FURTHER INFORMATION CONTACT: Ray 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:

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 96-NM-218-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

[[Page 59037]]

FAA, Transport Airplane Directorate, ANM-103, Attention: Rules Docket 
No. 96-NM-218-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

    On July 1, 1996, the FAA issued AD 96-14-07, amendment 39-9691 (61 
FR 35946, July 9, 1996), applicable to certain McDonnell Douglas Model 
MD-11 and MD-11F series airplanes. That AD requires:
    1. 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
    2. repetitive inspections to verify the correct position of the 
fuel pipe flange, and various follow-on actions.
    That action was 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 requirements of that 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.
    In the preamble to AD 96-14-07, the FAA specified that the actions 
required by that AD were considered ``interim action'' and that the 
manufacturer was developing a modification to positively address the 
unsafe condition. The FAA indicated that it may consider further 
rulemaking action once the modification was developed, approved, and 
available. The manufacturer now has developed such a modification, and 
the FAA has determined that further rulemaking action is indeed 
necessary; this proposed AD follows from that determination.

Explanation of Relevant Service Information

    The FAA has reviewed and approved McDonnell Douglas Service 
Bulletin MD11-28-082, dated July 29, 1996, which describes procedures 
for installation of a restraint on the tail tank fuel pipe. The 
restraint will minimize the migration of the fuel pipe and reduce the 
possibility of fuel leaks. Accomplishment of the installation would 
eliminate the need for the repetitive visual inspections.
    The FAA finds that accomplishment of the installation described in 
McDonnell Douglas Service Bulletin MD11-28-082 will positively address 
the unsafe condition identified as possible in-flight or ground fire 
due to fuel leaking from the fuel pipe coupling.

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 supersede AD 96-14-07 to continue 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. The proposed AD also would require 
installation of a restraint on the tail tank fuel pipe, which would 
constitute terminating action for the repetitive visual inspections 
requirements. The actions would be required to be accomplished in 
accordance with the service bulletin described previously.
    The FAA has determined that long term continued operational safety 
will be better assured by modifications or design changes to remove the 
source of the problem, rather than by repetitive inspection. Long term 
inspections may not be providing the degree of safety assurance 
necessary for the transport airplane fleet. This, coupled with a better 
understanding of the human factors associated with numerous repetitive 
inspections, has led the FAA to consider placing less emphasis on 
special procedures and more emphasis on design improvements. The 
proposed terminating modification requirement of this AD action is in 
consonance with these considerations.

Cost Impact

    There are approximately 152 McDonnell Douglas Model MD-11 and MD-
11F series airplanes of the affected design in the worldwide fleet. The 
FAA estimates that 42 airplanes of U.S. registry would be affected by 
this proposed AD.
    The actions that are currently required by AD 96-14-07, and 
retained in this proposed AD, take approximately 6 work hours per 
airplane to accomplish, at an average labor rate of $60 per work hour. 
Based on these figures, the cost impact of the currently required 
actions on U.S. operators is estimated to be $15,120, or $360 per 
airplane, per inspection cycle.
    The new actions that are proposed in this AD action would take 
approximately 3 work hours per airplane to accomplish, at an average 
labor rate of $60 per work hour. Required parts would be supplied by 
the manufacturer at no cost to the operators. Based on these figures, 
the cost impact of the proposed requirements of this AD on U.S. 
operators is estimated to be $7,560, or $180 per airplane.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the current or 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 removing amendment 39-9691 (61 FR 
35946, July 9, 1996), and by adding a

[[Page 59038]]

new airworthiness directive (AD), to read as follows:

McDonnell Douglas: Docket 96-NM-218-AD. Supersedes AD 96-14-07, 
Amendment 39-9691.

    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 
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 (f) 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:

Restatement of Requirements of AD 96-14-07, Amendment 39-9691

    (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 July 24, 1996 (the 
effective date AD 96-14-07, amendment 39-9691), 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, amendment 39-8095; 
whichever occurs first.
    (b) Condition 1. No Discrepancy Found. 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) Condition 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) Condition 1. 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. Discrepancy Found; O-Ring Not Exposed. 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) Condition 2. 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) Condition 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. Discrepancy Found; O-Ring Exposed. 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.

New Requirements of This AD

    (e) Within 24 months after the effective date of this AD, 
install a restraint on the tail tank fuel pipe in accordance with 
McDonnell Douglas Service Bulletin MD11-28-082, dated July 29, 1996. 
Accomplishment of the installation constitutes terminating action 
for the repetitive inspection requirements of this AD.
    (f) 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.

    (g) 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 November 13, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-29607 Filed 11-19-96; 8:45 am]
BILLING CODE 4910-13-U