[Federal Register Volume 71, Number 101 (Thursday, May 25, 2006)]
[Proposed Rules]
[Pages 30086-30088]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-8010]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-24864; Directorate Identifier 2006-NM-072-AD]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model DC-10-10, DC-
10-10F, DC-10-30, DC-10-30F (KDC-10), DC-10-40, and DC-10-40F Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for certain McDonnell Douglas airplanes, identified above. This 
proposed AD would require reducing the length of the sump drain collar 
and replacing the fuel tank sump drain lockring for fuel tanks 1, 2, 
and 3; and reducing the length of the drain outlet barrel for the 
auxiliary fuel tank, if applicable. For airplanes with an auxiliary 
fuel tank, this proposed AD also would require relocating the sump 
drain outlet to allow draining the sumps without opening the doors of 
the main landing gear wheel well. This proposed AD results from fuel 
system reviews conducted by the manufacturer. We are proposing this AD 
to reduce the potential of ignition sources inside fuel tanks in the 
event of a lightning strike, which, in combination with flammable fuel 
vapors, could result in arcing in the fuel tank, fuel tank explosions, 
and consequent loss of the airplane.

DATES: We must receive comments on this proposed AD by July 10, 2006.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD.
     DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility, U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, room PL-401, 
Washington, DC 20590.
     Fax: (202) 493-2251.
     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    Contact Boeing Commercial Airplanes, Long Beach Division, 3855 
Lakewood Boulevard, Long Beach, California 90846, Attention: Data and 
Service Management, Dept. C1-L5A (D800-0024), for the service 
information identified in this proposed AD.

FOR FURTHER INFORMATION CONTACT: Samuel Lee, Aerospace Engineer, 
Propulsion Branch, ANM-140L, FAA, Los Angeles Aircraft Certification 
Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; 
telephone (562) 627-5262; fax (562) 627-5210.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to submit any relevant written data, views, or 
arguments regarding this proposed AD. Send your comments to an address 
listed in the ADDRESSES section. Include the docket number ``FAA-2006-
24864; Directorate Identifier 2006-NM-072-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the proposed AD. We will 
consider all comments received by the closing date and may amend the 
proposed AD in light of those comments.
    We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this proposed AD. Using the search function of 
that Web site, anyone can find and read the comments in any of our 
dockets, including the name of the individual who sent the comment (or 
signed the comment on behalf of an association, business, labor union, 
etc.). You may review DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR 19477-78), or you 
may visit http://dms.dot.gov.

Examining the Docket

    You may examine the AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Management Facility office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The Docket Management Facility office (telephone (800) 647-
5227) is located on the plaza level of the Nassif Building at the DOT 
street address stated in the ADDRESSES section. Comments will be 
available in the AD docket shortly after the Docket Management System 
receives them.

[[Page 30087]]

Discussion

    The FAA has examined the underlying safety issues involved in fuel 
tank explosions on several large transport airplanes, including the 
adequacy of existing regulations, the service history of airplanes 
subject to those regulations, and existing maintenance practices for 
fuel tank systems. As a result of those findings, we issued a 
regulation titled ``Transport Airplane Fuel Tank System Design Review, 
Flammability Reduction and Maintenance and Inspection Requirements'' 
(67 FR 23086, May 7, 2001). In addition to new airworthiness standards 
for transport airplanes and new maintenance requirements, this rule 
included Special Federal Aviation Regulation No. 88 (``SFAR 88,'' 
Amendment 21-78, and subsequent Amendments 21-82 and 21-83).
    Among other actions, SFAR 88 requires certain type design (i.e., 
type certificate (TC) and supplemental type certificate (STC)) holders 
to substantiate that their fuel tank systems can prevent ignition 
sources in the fuel tanks. This requirement applies to type design 
holders for large turbine-powered transport airplanes and for 
subsequent modifications to those airplanes. It requires them to 
perform design reviews and to develop design changes and maintenance 
procedures if their designs do not meet the new fuel tank safety 
standards. As explained in the preamble to the rule, we intended to 
adopt airworthiness directives to mandate any changes found necessary 
to address unsafe conditions identified as a result of these reviews.
    In evaluating these design reviews, we have established four 
criteria intended to define the unsafe conditions associated with fuel 
tank systems that require corrective actions. The percentage of 
operating time during which fuel tanks are exposed to flammable 
conditions is one of these criteria. The other three criteria address 
the failure types under evaluation: Single failures, single failures in 
combination with a latent condition(s), and in-service failure 
experience. For all four criteria, the evaluations included 
consideration of previous actions taken that may mitigate the need for 
further action.
    We have determined that the actions identified in this AD are 
necessary to reduce the potential of ignition sources inside fuel 
tanks, which, in combination with flammable fuel vapors, could result 
in fuel tank explosions and consequent loss of the airplane.
    Review of the lightning protection for the valve installation for 
the sump drain of the fuel tanks showed that the drain valves must be 
insulated. If the fuel level is below the drain valve body, and there 
is a lightning strike, electrical current could travel from the 
airplane skin up the sump drain collar into the valve housing. This 
condition, in combination with a lightning strike and flammable fuel 
vapors, could result in arcing in the fuel tank, fuel tank explosions, 
and consequent loss of the airplane.

Relevant Service Information

    We have reviewed McDonnell Douglas DC-10 Service Bulletin 28-61, 
dated January 17, 1978. The service bulletin describes procedures for 
reducing the length of the sump drain collar and replacing the fuel 
tank sump drain lockring for fuel tanks 1, 2, and 3 with an improved 
lockring; and reducing the length of the drain outlet barrel for the 
auxiliary fuel tank, if applicable.
    McDonnell Douglas DC-10 Service Bulletin 28-61 specifies that for 
certain airplanes, before or concurrently with the modification of the 
sump drain outlets described above, the sump drain outlet for the 
auxiliary tank must be relocated to allow draining the sumps without 
opening the doors of the main landing gear wheel well. The procedures 
for doing this action are described in McDonnell Douglas DC-10 Bulletin 
28-19, Revision 1, dated October 15, 1973. This action applies only to 
those airplanes identified as Group II in McDonnell Douglas DC-10 
Service Bulletin 28-61, that are also contained in the effectivity of 
McDonnell Douglas DC-10 Bulletin 28-19, Revision 1.
    Accomplishing the actions specified in the service information is 
intended to adequately address the unsafe condition.

FAA's Determination and Requirements of the Proposed AD

    We have evaluated all pertinent information and identified an 
unsafe condition that is likely to exist or develop on other airplanes 
of this same type design. For this reason, we are proposing this AD, 
which would require accomplishing the actions specified in the service 
information described previously, except as discussed under 
``Difference Between the Proposed AD and Service Bulletin 28-61.''

Difference Between the Proposed AD and Service Bulletin 28-61

    McDonnell Douglas DC-10 Service Bulletin 28-61 recommends doing the 
modification at the operator's convenience, which would not ensure an 
adequate level of safety for the affected fleet. In developing an 
appropriate compliance time for this AD, we considered the 
manufacturer's recommendation, the degree of urgency associated with 
the subject unsafe condition, and the average utilization of the 
affected fleet. In light of all of these factors, we find that a 
compliance time of 60 months after the effective date of this AD 
represents an appropriate interval of time for affected airplanes to 
continue to operate without compromising safety. This difference has 
been coordinated with Boeing, and Boeing concurred.

Costs of Compliance

    There are about 135 airplanes of the affected design in the 
worldwide fleet. The following table provides the estimated costs for 
U.S. operators to comply with this proposed AD. The labor rate is $80 
per work hour.

                                                                     Estimated Costs
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                                                                                                      Number of U.S.-
             Action                 Work hours           Parts            Cost per  airplane       registered  airplanes             Fleet cost
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For all airplanes: Reduce the     3 to 15.......  $720 to $4,858.....  $960 to $6,058..........  109.....................  $104,640 to $660,322.
 length of the sump drain collar
 and replace the fuel tank sump
 drain for fuel tanks 1, 2, and
 3.
For airplanes with an auxiliary   6 to 15.......  $0 to $720.........  $480 to $1,920..........  Up to 109...............  $52,320 to $209,280.
 fuel tank: Reduce the length of
 the drain outlet barrel for the
 auxiliary fuel tank.

[[Page 30088]]

 
Prior requirement for certain     1 to 6........  The manufacturer     $80 to $480.............  Up to 109...............  $8,720 to $52,320.
 airplanes.                                        states that it
                                                   will supply
                                                   required parts to
                                                   the operators at
                                                   no cost.
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Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, Section 106, describes the 
authority of the FAA Administrator. Subtitle VII, Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701, ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    We have determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would not 
have a substantial direct effect 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.
    For the reasons discussed above, I certify that the 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. 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.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this proposed AD and placed it in the AD docket. See the 
ADDRESSES section for a location to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 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. The Federal Aviation Administration (FAA) amends Sec.  39.13 by 
adding the following new airworthiness directive (AD):

McDonnell Douglas: Docket No. FAA-2006-24864; Directorate Identifier 
2006-NM-072-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by July 10, 
2006.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to McDonnell Douglas Model DC-10-10, DC-10-
10F, DC-10-30, DC-10-30F (KDC-10), DC-10-40, and DC-10-40F 
airplanes, certificated in any category; as identified in McDonnell 
Douglas DC-10 Service Bulletin 28-61, dated January 17, 1978.

Unsafe Condition

    (d) This AD results from fuel system reviews conducted by the 
manufacturer. We are issuing this AD to reduce the potential of 
ignition sources inside fuel tanks in the event of a lightning 
strike, which, in combination with flammable fuel vapors, could 
result in arcing in the fuel tank, fuel tank explosions, and 
consequent loss of the airplane.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within the compliance times specified, unless the 
actions have already been done.

Corrective Actions

    (f) Within 60 months after the effective date of this AD: Reduce 
the length of the sump drain collar and replace the fuel tank sump 
drain lockring for fuel tanks 1, 2, and 3; and reduce the length of 
the drain outlet barrel for the auxiliary fuel tank, as applicable; 
by doing all the applicable actions in accordance with the 
Accomplishment Instructions of McDonnell Douglas DC-10 Service 
Bulletin 28-61, dated January 17, 1978.

Prior Requirement

    (g) For airplanes identified as Group II airplanes in McDonnell 
Douglas DC-10 Service Bulletin 28-61, dated January 17, 1978, that 
are also contained in the effectivity of McDonnell Douglas DC-10 
Bulletin 28-19, Revision 1, dated October 15, 1973: Before the 
actions in paragraph (f) of this AD, relocate the sump drain outlet 
for the auxiliary tank in accordance with the Accomplishment 
Instructions of McDonnell Douglas DC-10 Bulletin 28-19, Revision 1, 
dated October 15, 1973.

Alternative Methods of Compliance (AMOCs)

    (h)(1) The Manager, Los Angeles Aircraft Certification Office 
(ACO), FAA, has the authority to approve AMOCs for this AD, if 
requested in accordance with the procedures found in 14 CFR 39.19.
    (2) Before using any AMOC approved in accordance with Sec.  
39.19 on any airplane to which the AMOC applies, notify the 
appropriate principal inspector in the FAA Flight Standards 
Certificate Holding District Office.

    Issued in Renton, Washington, on May 17, 2006.
Kevin M. Mullin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E6-8010 Filed 5-24-06; 8:45 am]
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