[Federal Register Volume 71, Number 95 (Wednesday, May 17, 2006)]
[Proposed Rules]
[Pages 28619-28622]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-7476]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-24780; Directorate Identifier 2006-NM-069-AD]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model DC-10-10, DC-
10-10F, DC-10-15, DC-10-30, DC-10-30F (KC-10A and 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 installing or replacing with improved parts, 
as applicable, the bonding straps between the metallic

[[Page 28620]]

frame of the fillet and the wing leading edge ribs, on both the left 
and right sides. 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 
severe lightning strike, which, in combination with flammable fuel 
vapors, could result in fuel tank explosions and consequent loss of the 
airplane.

DATES: We must receive comments on this proposed AD by July 3, 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-
24780; Directorate Identifier 2006-NM-069-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.

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.
    Engineering review of the extended wing-to-fuselage fillet on 
certain McDonnell Douglas Model DC-10-10, DC-10-10F, DC-10-15, DC-10-
30, DC-10-30F (KC-10A and KDC-10), DC-10-40, and DC-10-40F airplanes 
revealed an increase in the nonmetallic area of the fillet. Engineering 
reviews of the conventional wing-to-fuselage fillet on certain of the 
same airplane models revealed that the support ribs of the fuselage-
mounted fillet are not grounded, but should be. These conditions, in 
combination with a severe lightning strike and flammable fuel vapors, 
could result in fuel tank explosions and consequent loss of the 
airplane.

Relevant Service Information

    We have reviewed McDonnell Douglas DC-10 Service Bulletin 53-109, 
Revision 4, dated October 7, 1992 (for airplanes with extended wing-to-
fuselage fillets); and McDonnell Douglas DC-10 Service Bulletin 53-111, 
Revision 3, dated August 24, 1992 (for airplanes with conventional 
wing-to-fuselage fillets). The service bulletins describe procedures 
for installing or replacing with improved parts, as applicable, the 
bonding straps between the metallic frame of the fillet and the wing 
leading edge ribs, on both the left and right sides. For airplanes with 
extended wing-to-fuselage fillets, the service bulletin indicates that 
there are

[[Page 28621]]

six bonding straps. For airplanes with conventional wing-to-fuselage 
fillets, the service bulletin indicates that there are ten bonding 
straps. 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 the Service Bulletins.''

Difference Between the Proposed AD and the Service Bulletins

    McDonnell Douglas DC-10 Service Bulletin 53-109 recommends doing 
the installation or replacement at the earliest practical maintenance 
period, and McDonnell Douglas DC-10 Service Bulletin 53-111 recommends 
doing the installation or maintenance at the first convenient check, 
but no later than 7,500 flight-hours after receiving the service 
bulletin. We have determined that these intervals would not address the 
identified unsafe condition soon enough to 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 the earlier of 7,500 flight 
hours or 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 concurs.

Costs of Compliance

    There are about 457 airplanes of the affected design in the 
worldwide fleet. This proposed AD would affect about 280 airplanes of 
U.S. registry. The proposed actions would take between 9 and 17 work 
hours per airplane, at an average labor rate of $80 per work hour. 
Required parts would cost between $3,720 and $4,169 per airplane. Based 
on these figures, the estimated cost of the proposed AD is between 
$4,440 and $5,529 per airplane, or between $1,243,200 and $1,548,120 
for the U.S.-registered fleet.

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-2006-24780; Directorate Identifier 
2006-NM-069-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by July 3, 
2006.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to McDonnell Douglas Model DC-10-10, DC-10-
10F, DC-10-15, DC-10-30, DC-10-30F (KC-10A and KDC-10), DC-10-40, 
DC-10-40F, airplanes, certificated in any category; as identified in 
the applicable service bulletin listed in Table 1 of this AD.

                                           Table 1.--Service Bulletins
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                                            Revision
McDonnell Douglas DC-10 service bulletin     level           Date                 For airplanes with--
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53-109..................................            4  October 7, 1992  Extended wing-to-fuselage fillets.
53-111..................................            3  August 24, 1992  Conventional wing-to-fuselage fillets.
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[[Page 28622]]

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 severe 
lightning strike, which, in combination with flammable fuel vapors, 
could result in 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.

Installation or Replacement

    (f) Within 7,500 flight hours or 60 months after the effective 
date of this AD, whichever occurs earlier: Install or replace with 
improved parts, as applicable, the bonding straps between the 
metallic frame of the fillet and the wing leading edge ribs, on both 
the left and right sides, in accordance with the Accomplishment 
Instructions of the applicable service bulletin identified in Table 
1 of this AD.

Alternative Methods of Compliance (AMOCs)

    (g)(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 8, 2006.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E6-7476 Filed 5-16-06; 8:45 am]
BILLING CODE 4910-13-P