
[Federal Register: August 29, 2008 (Volume 73, Number 169)]
[Proposed Rules]               
[Page 50894-50896]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr29au08-15]                         

-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-0934; Directorate Identifier 2008-NM-113-AD]
RIN 2120-AA64

 
Airworthiness Directives; McDonnell Douglas Model DC-9-30, DC-9-
40, and DC-9-50 Series Airplanes, Model DC-9-81 (MD-81), DC-9-82 (MD-
82), DC-9-83 (MD-83), and DC-9-87 (MD-87) Airplanes, and Model MD-88 
and MD-90-30 Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: We propose to adopt a new airworthiness directive (AD) for the 
McDonnell Douglas airplanes listed above. This proposed AD would 
require modifying the fuel boost pumps for the center wing, and forward 
or aft auxiliary fuel tanks. This proposed AD results from fuel system 
reviews conducted by the manufacturer. We are proposing this AD to 
prevent possible sources of ignition in a fuel tank caused by an 
electrical fault or uncommanded dry operation of the fuel boost pumps. 
An ignition source in the fuel tank could result in a fire or an 
explosion and consequent loss of the airplane.

DATES: We must receive comments on this proposed AD by October 14, 
2008.

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 AD, contact Boeing 
Commercial Airplanes, Long Beach Division, 3855 Lakewood Boulevard, 
Long Beach, California 90846, Attention: Data and Service Management, 
Dept. C1-L5A (D800-0024).

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: 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 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-2008-0934; 
Directorate Identifier 2008-NM-113-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 Airplane Fuel Tank System Design

[[Page 50895]]

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.
    Boeing has determined a need to protect the fuel boost pump stator 
lead wires from contacting the pump rotor/shaft assembly. Lead wire 
contact and the resulting chafing may result in an ignition source 
(energized rotor assembly) being produced in the fuel boost pump inlet 
that could propagate into the fuel tank when the fuel boost pump inlet 
is not fully covered by fuel. Replacement of the fuel boost pumps will 
minimize the risk of potential ignition sources that may occur within 
the fuel tanks at critical fuel boost pump locations in the center 
wing, and forward or aft auxiliary fuel tanks. An ignition source in 
the fuel tank could result in a fire or an explosion and consequent 
loss of the airplane.

Relevant Service Information

    We have reviewed Boeing Service Bulletins DC9-28-212 (for Model DC-
9-30, DC-9-40, and DC-9-50 series airplanes, and 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) 
and MD90-28-010, (for MD-90-30 airplanes), both dated February 22, 
2008. The service bulletins describe procedures for modifying the fuel 
boost pumps for the center wing, and forward or aft auxiliary fuel 
tanks. The modification includes changing or replacing the boost pumps, 
as applicable. The change includes incorporating a stator lead wire 
position retention feature.
    The Boeing service bulletins recommend concurrent accomplishment of 
the modification in Argo-Tech Service Bulletin 398000-28-2, dated 
November 8, 2007. The Argo-Tech Service Bulletin describes procedures 
for modifying the fuel boost pumps.

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 Boeing service information described previously.

Costs of Compliance

    We estimate that this proposed AD would affect 804 airplanes of 
U.S. registry. The following table provides the estimated costs for 
U.S. operators to comply with the modification specified in this 
proposed AD. The fleet cost is estimated to be between $1,246,200 and 
$13,087,512.

----------------------------------------------------------------------------------------------------------------
                                         Work    Average labor
            Airplane group              hours    rate per hour           Parts               Cost per product
----------------------------------------------------------------------------------------------------------------
Group 1, Configurations 1 and 2......        1             $80  Between $1,470 and       Between $1,550 and
                                                                 $16,038.                 $16,118.
Group 2, Configurations 1 and 2;             2              80  Between $1,470 and       Between $1,630 and
 Group 7, Configuration 2.                                       $16,038.                 $16,198.
Group 3, Configurations 1 and 2......        3              80  Between $1,470 and       Between $1,710 and
                                                                 $16,038.                 $16,278.
Group 4, Configurations 1 and 2......        1              80  Between $1,470 and       Between $1,550 and
                                                                 $16,038.                 $16,118.
Group 5, Configurations 1 and 2......        2              80  Between $1,470 and       Between $1,630 and
                                                                 $16,038.                 $16,198.
Group 6, Configurations 1 and 2;             1              80  Between $1,470 and       Between $1,550 and
 Group 8, Configurations 1 and 2.                                $16,038.                 $16,118.
----------------------------------------------------------------------------------------------------------------

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

[[Page 50896]]

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

McDonnell Douglas: Docket No. FAA-2008-0934; Directorate Identifier 
2008-NM-113-AD.

Comments Due Date

    (a) We must receive comments by October 14, 2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to McDonnell Douglas Model DC-9-31, DC-9-32, 
DC-9-32 (VC-9C), DC-9-32F, DC-9-32F (C-9A, C-9B), DC-9-33F, DC-9-34, 
DC-9-34F, DC-9-41, DC-9-51, DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-
83 (MD-83), and DC-9-87 (MD-87), MD-88, and MD-90-30 airplanes; 
certificated in any category; as identified in Boeing Service 
Bulletins DC9-28-212 and MD90-28-010, both dated February 22, 2008.

Unsafe Condition

    (d) This AD results from fuel system reviews conducted by the 
manufacturer. We are issuing this AD to prevent possible sources of 
ignition in a fuel tank caused by electrical fault or uncommanded 
dry operation of the fuel boost pumps. An ignition source in the 
fuel tank could result in a fire or an explosion and consequent loss 
of the airplane.

Compliance

    (e) Comply with this AD within the compliance times specified, 
unless already done.

Modification

    (f) Within 60 months after the effective date of this AD: Modify 
the fuel boost pumps for the center wing, and forward or aft 
auxiliary fuel tanks, as applicable, by doing all the applicable 
actions specified in the Accomplishment Instructions of Boeing 
Service Bulletin DC9-28-212 or MD90-28-010, both dated February 22, 
2008, as applicable.

Prior or Concurrent Action

    (g) Prior to or concurrently with accomplishing the modification 
required by paragraph (f) of this AD: Do the modification specified 
in Argo-Tech Service Bulletin 398000-28-2, dated November 8, 2007.

Alternative Methods of Compliance (AMOCs)

    (h)(1) The Manager, Los Angeles Aircraft Certification Office 
(ACO), FAA, ATTN: 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; has the authority to approve 
AMOCs for this AD, if requested using 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 August 21, 2008.
Kevin Hull,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E8-20082 Filed 8-28-08; 8:45 am]

BILLING CODE 4910-13-P
