[Federal Register Volume 72, Number 107 (Tuesday, June 5, 2007)]
[Proposed Rules]
[Pages 31003-31005]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-10756]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-28351; Directorate Identifier 2007-NM-074-AD]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model MD-11, MD-11F, 
DC-10-30 and DC-10-30F (KC-10A and KDC-10), DC-10-40, DC-10-40F, and 
MD-10-30F 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 Model MD-11, MD-11F, DC-10-30 and DC-10-
30F (KC-10A and KDC-10), DC-10-40, DC-10-40F, and MD-10-30F airplanes. 
This proposed AD would require measuring the electrical resistance of 
the bond between the No. 2 fuel transfer pump adapter surface of the 
fuel tank and the fuel transfer pump housing flange, and performing 
corrective and other specified actions as applicable. This proposed AD 
results from a design review of the fuel tank systems. We are proposing 
this AD to prevent inadequate bonding between the No. 2 fuel transfer 
pump adapter surface of the fuel tank and the fuel transfer pump 
housing flange. Inadequate bonding could result in a potential ignition 
source inside the fuel tank if the fuel transfer pump and structure 
interface are not submerged in fuel, which, in combination with 
flammable fuel vapors, could result in a fuel tank explosion and 
consequent loss of the airplane.

DATES: We must receive comments on this proposed AD by July 20, 2007.

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: Serj Harutunian, Aerospace Engineer, 
Propulsion Branch, ANM-140L, FAA, Los Angeles Aircraft Certification 
Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; 
telephone (562) 627-5254; 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-2007-
28351; Directorate Identifier 2007-NM-074-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'' 
(66 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

[[Page 31004]]

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.
    Model DC-10 airplanes have a fuel boost pump and a fuel transfer 
pump mounted to the fuel tank No. 2 lower skin. The instructions for 
early DC-10s called out electrical bonding to structure on both fuel 
transfer pump housings; however, a later drawing change did not call 
out bonding for the fuel transfer pump housing. The same condition 
exists on Model MD-11 airplanes. It is unknown whether there is an 
adequate bond on these airplanes, and operators need to make that 
determination. Inadequate bonding could result in a potential ignition 
source inside the fuel tank if the fuel transfer pump and structure 
interface are not submerged in fuel, which, in combination with 
flammable fuel vapors, could result in a fuel tank explosion and 
consequent loss of the airplane.

Relevant Service Information

    We have reviewed Boeing Service Bulletins DC10-28-250 and MD11-28-
129, both dated July 26, 2006. The service bulletins describe 
procedures for measuring the electrical resistance between the No. 2 
fuel transfer pump adapter surface of the fuel tank and the fuel 
transfer pump housing flange, and performing corrective and other 
specified actions as applicable. The corrective actions include 
electrically bonding the fuel tank No. 2 fuel transfer pump access door 
surfaces and fuel pump housing if the resistance measurement is more 
than 2.5 milliohms. The other specified actions include an electrical 
resistance bonding test to verify the electrical resistance between the 
fuel transfer pump housing and the structure is 2.5 milliohms maximum. 
For airplanes on which the electrical resistance is not achieved, the 
procedures include reworking the electrical bond until that electrical 
resistance is achieved. 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.

Costs of Compliance

    There are about 573 airplanes of the affected design in the 
worldwide fleet. This proposed AD would affect about 399 airplanes of 
U.S. registry. The proposed measurement would take about 1 work hour 
per airplane, at an average labor rate of $80 per work hour. Based on 
these figures, the estimated cost of the proposed AD for U.S. operators 
is $31,920, or $80 per airplane.

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-2007-28351; Directorate Identifier 
2007-NM-074-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by July 20, 
2007.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to McDonnell Douglas Model MD-11, MD-11F, 
DC-10-30 and DC-10-30F (KC-10A and KDC-10), DC-10-40, DC-10-40F, and 
MD-10-30F airplanes, certificated in any category; as identified in 
Boeing Service Bulletins DC10-28-250 and MD11-28-129, both dated 
July 26, 2006.

Unsafe Condition

    (d) This AD results from a design review of the fuel tank 
systems. We are issuing this AD to prevent inadequate bonding 
between the No. 2 fuel transfer pump adapter surface of the fuel 
tank and the fuel transfer pump housing flange. Inadequate bonding 
could result in a potential ignition source inside the fuel tank if 
the fuel transfer pump and

[[Page 31005]]

structure interface are not submerged in fuel, which, in combination 
with flammable fuel vapors, could result in a fuel tank explosion 
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.

Measure Electrical Resistance/Corrective & Other Specified Actions

    (f) Within 60 months after the effective date of this AD: 
Measure the electrical resistance of the bond between the No. 2 fuel 
transfer pump adapter surface of the fuel tank and the fuel transfer 
pump housing flange in accordance with the Accomplishment 
Instructions of Boeing Service Bulletin DC10-28-250 or MD11-28-129, 
both dated July 26, 2006, as applicable.
    (1) If the resistance measurement is 2.5 milliohms or less: No 
further action is required by this paragraph.
    (2) If the resistance measurement is more than 2.5 milliohms: 
Before further flight, electrically bond the fuel tank No. 2 fuel 
transfer pump housing surfaces in accordance with the service 
bulletin.
    (3) Before further flight thereafter, do an electrical 
resistance bonding test to verify the electrical resistance between 
the fuel transfer pump housing and the structure is 2.5 milliohms 
maximum. If that electrical resistance is not achieved, rework the 
electrical bond until the electrical resistance is achieved. Do the 
actions in accordance with the service bulletin.

Alternative Methods of Compliance (AMOCs)

    (g)(1) The Manager, Los Angeles Aircraft Certification Office 
(LAACO), FAA, has the authority to approve AMOCs for this AD, if 
requested in accordance with the procedures found in 14 CFR 39.19.
    (2) To request a different method of compliance or a different 
compliance time for this AD, follow the procedures in 14 CFR 39.19. 
Before using any approved AMOC on any airplane to which the AMOC 
applies, notify your appropriate principal inspector (PI) in the FAA 
Flight Standards District Office (FSDO), or lacking a PI, your local 
FSDO.

    Issued in Renton, Washington, on May 25, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E7-10756 Filed 6-4-07; 8:45 am]
BILLING CODE 4910-13-P