
[Federal Register: June 18, 2010 (Volume 75, Number 117)]
[Proposed Rules]               
[Page 34661-34663]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr18jn10-19]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2010-0549; Directorate Identifier 2010-NM-109-AD]
RIN 2120-AA64

 
Airworthiness Directives; McDonnell Douglas Corporation Model DC-
9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), and 
MD-88 Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for 
certain Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-
87 (MD-87), and MD-88 airplanes. This proposed AD would require 
installing fuel level float and pressure switch in-line fuses on the 
wing forward spars and forward and aft auxiliary fuel tanks, depending 
on the airplane configuration. This proposed AD results from fuel 
system reviews conducted by the manufacturer. We are proposing this AD 
to prevent 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.

DATES: We must receive comments on this proposed AD by August 2, 2010.

ADDRESSES: You may send comments by any of the following methods:
     Federal eRulemaking Portal: Go to http://
www.regulations.gov. Follow the instructions for submitting comments.
     Fax: 202-493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590.
     Hand Delivery: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays.
    For service information identified in this proposed AD, contact 
Boeing Commercial Airplanes, Attention: Data & Services Management, 
3855 Lakewood Boulevard, MC D800-0019, Long Beach, California 90846-
0001; telephone 206-544-5000, extension 2; fax 206-766-5683; e-mail 
dse.boecom@boeing.com; Internet https://www.myboeingfleet.com. You may 
review copies of the referenced service information at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, 
Washington. For information on the availability of this material at the 
FAA, call 425-227-1221.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://
www.regulations.gov; or in person at the Docket Management Facility 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains this proposed AD, the regulatory 
evaluation, any comments received, and other information. The street 
address for the Docket Office (telephone 800-647-5527) is in the 
ADDRESSES section. Comments will be available in the AD docket shortly 
after receipt.

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

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposed AD. Send your comments to an address 
listed under the ADDRESSES section. Include ``Docket No. FAA-2010-0549; 
Directorate Identifier 2010-NM-109-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed AD. We 
will consider all comments received by the closing date and may amend 
this proposed AD because of those comments.
    We will post all comments we receive, without change, to http://
www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive about this proposed AD.

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

[[Page 34662]]

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 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.
    An investigation by Boeing has determined that fuel level float 
switch wires located on the left and right wing forward spars, the 
center tank forward spar, and the forward and aft auxiliary fuel tanks 
and pressure switch wires located on the center tank forward spar are 
routed in the same bundles as power wires. If a short circuit between a 
fuel level float or pressure switch wire and a power wire occurs, an 
over-current can cause excessive temperature in the fuel level float or 
pressure switch wire, which could result in damage and become a 
potential ignition source.

Relevant Service Information

    We have reviewed Boeing Service Bulletin MD80-28-226, dated April 
14, 2010. The service bulletin describes procedures for installing fuel 
level float and pressure switch in-line fuses, including wiring 
changes, in the following locations:
     On the left, right, and center wing forward spars (Groups 
1 through 6).
     On the left, right, and center wing forward spars, and aft 
auxiliary fuel tank (Groups 7 and 8).
     On the left, right, and center wing forward spars, forward 
auxiliary fuel tank, and aft auxiliary fuel tank (Groups 9 through 11).

FAA's Determination and Requirements of This Proposed AD

    We are proposing this AD because we evaluated all relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of these same type 
designs. This proposed AD would require accomplishing the actions 
specified in the service information described previously.

Costs of Compliance

    We estimate that this proposed AD would affect 640 airplanes of 
U.S. registry. The following table provides the estimated costs, 
depending on the airplane configuration, for U.S. operators to comply 
with this proposed AD.

                                                                 Table--Estimated Costs
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                                                             Average                                                Number of U.S.-
              Action                      Work hours        labor rate          Parts           Cost per product      registered         Fleet cost
                                                             per hour                                                  airplanes
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Installation......................  Between 7 and 17.....          $85  Between $817 and      Between $1,412 and               640  Between $903,680 and
                                                                         $1,725.               $3,170.                               $2,028,800,
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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 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 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. 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.
    You can find our regulatory evaluation and the estimated costs of 
compliance in the AD Docket.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, 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:

[[Page 34663]]

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 FAA amends Sec.  39.13 by adding the following new AD:

McDonnell Douglas Corporation: Docket No. FAA-2010-0549; Directorate 
Identifier 2010-NM-109-AD.

Comments Due Date

    (a) We must receive comments by August 2, 2010.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to McDonnell Douglas Corporation Model DC-9-
81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), and 
MD-88 airplanes; certificated in any category; as identified in 
Boeing Service Bulletin MD80-28-226, dated April 14, 2010.

Subject

    (d) Air Transport Association (ATA) of America Code 28: Fuel.

Unsafe Condition

    (e) This AD results from fuel system reviews conducted by the 
manufacturer. The Federal Aviation Administration is issuing this AD 
to prevent 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.

Compliance

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

Fuse Installation

    (g) Within 60 months after the effective date of this AD, 
install fuel level float and pressure switch in-line fuses, and do 
applicable wiring changes, in the applicable locations specified in 
paragraph (g)(1), (g)(2), or (g)(3) of this AD. Do the actions in 
accordance with the Accomplishment Instructions of Boeing Service 
Bulletin MD80-28-226, dated April 14, 2010.
    (1) For Groups 1 through 6: On the left, right, and center wing 
forward spars.
    (2) For Groups 7 and 8: On the left, right, and center wing 
forward spars, and aft auxiliary fuel tank.
    (3) For Groups 9 through 11: On the left, right, and center wing 
forward spars, forward auxiliary fuel tank, and aft auxiliary fuel 
tank.

Alternative Methods of Compliance (AMOCs)

    (h)(1) The Manager, Los Angeles Aircraft Certification Office, 
FAA, has the authority to approve AMOCs for this AD, if requested 
using the procedures found in 14 CFR 39.19. Send information to 
ATTN: Samuel Lee, Aerospace Engineer, Propulsion Branch, ANM-140L, 
FAA, Los Angeles Aircraft Certification Office (ACO), 3960 Paramount 
Boulevard, Lakewood, California 90712-4137; telephone (562) 627-
5262; fax (562) 627-5210.
    (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 principal maintenance inspector (PMI) or 
principal avionics inspector (PAI), as appropriate, or lacking a 
principal inspector, your local Flight Standards District Office. 
The AMOC approval letter must specifically reference this AD.

    Issued in Renton, Washington, on June 10, 2010.
Jeffrey E. Duven,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2010-14796 Filed 6-17-10; 8:45 am]
BILLING CODE 4910-13-P

