Document ID: FAA-2008-0736-0001
Agency: faa
Document Type: Rule
Title: Airworthiness Directives; McDonnell Douglas Model DC-9-14, DC-9- 15, and DC-9-15F Airplanes, and DC-9-20, DC-9-30, DC-9-40, and DC-9-50 Series Airplanes
Posted Date: 2008-08-01T04:00Z

[Federal Register: August 1, 2008 (Volume 73, Number 149)]
[Proposed Rules]               
[Page 44937-44939]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr01au08-10]                         

========================================================================
Proposed Rules
                                                Federal Register
________________________________________________________________________

This section of the FEDERAL REGISTER contains notices to the public of 
the proposed issuance of rules and regulations. The purpose of these 
notices is to give interested persons an opportunity to participate in 
the rule making prior to the adoption of the final rules.

========================================================================

[[Page 44937]]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-0736; Directorate Identifier 2008-NM-102-AD]
RIN 2120-AA64

 
Airworthiness Directives; McDonnell Douglas Model DC-9-14, DC-9-
15, and DC-9-15F Airplanes, and DC-9-20, DC-9-30, DC-9-40, and DC-9-50 
Series 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 McDonnell Douglas airplanes listed above. This proposed AD 
would require installing a dam assembly for the container of the fuel 
boost pump of the center tank located in the right main tank, and doing 
the related investigative actions, and corrective actions if necessary. 
This proposed AD results from fuel system reviews conducted by the 
manufacturer. We are proposing this AD to prevent the center tank fuel 
boost pump from operating in a fuel vapor zone and becoming a potential 
ignition source in the right main tank, potentially resulting in a fuel 
tank explosion and consequent loss of the airplane.

DATES: We must receive comments on this proposed AD by September 15, 
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: William S. Bond, Aerospace Engineer, 
Propulsion Branch, ANM-140L, FAA, Los Angeles Aircraft Certification 
Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; 
telephone (562) 627-5253; 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-2008-0736; 
Directorate Identifier 2008-NM-102-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 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.

[[Page 44938]]

    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.
    The manufacturer has found that a potential ignition source may 
occur in the boost pump container of the center fuel tank located in 
the right main tank. When the center fuel tank level is low, fuel from 
the boost pump container of the center fuel tank is drained allowing 
pumps to operate in a fuel vapor zone. Installing a dam in the boost 
pump container of the center fuel tank raises the retained fuel level 
in the container, keeping the boost pumps and connectors submerged in 
fuel. When the center fuel tank level is low, this condition, if not 
corrected, could cause a potential ignition source if a pump motor case 
or connector burn through occurred, resulting in a fuel tank explosion 
and consequent loss of the airplane.

Relevant Service Information

    We have reviewed Boeing Service Bulletin DC9-28-216, dated March 
18, 2008. The service bulletin describes procedures for installing a 
dam assembly for the container of the fuel boost pump of the center 
tank located in the right main tank and doing the related investigative 
and applicable corrective actions. The related investigative action is 
doing a leak check on the installation, and the applicable corrective 
action is reapplying sealant to repair any leak detected.

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 413 airplanes of 
U.S. registry. We also estimate that it would take about 3 or 7 work-
hours per product, depending on airplane configuration, to comply with 
this proposed AD. The average labor rate is $80 per work-hour. Required 
parts would cost $1,142 or $1,697 per product, depending on 
configuration of the airplane. Based on these figures, we estimate the 
cost of this proposed AD to the U.S. operators to be $570,766 or 
$932,141, or $1,382 or $2,257 per product, depending on configuration 
of the 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 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, 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-2008-0736; Directorate Identifier 
2008-NM-102-AD.

Comments Due Date

    (a) We must receive comments by September 15, 2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to McDonnell Douglas Model DC-9-14, DC-9-15, 
DC-9-15F, DC-9-21, DC-9-31, DC-9-32, DC-9-32 (VC-9C), DC-9-32F, DC-
9-33F, DC-9-34, DC-9-34F, DC-9-32F (C-9A, C-9B), DC-9-41, and DC-9-
51 airplanes, certificated in any category; as identified in Boeing 
Service Bulletin DC9-28-216, dated March 18, 2008.

Unsafe Condition

    (d) This AD results from fuel system reviews conducted by the 
manufacturer. We are issuing this AD to prevent the center tank fuel 
boost pump from operating in a fuel vapor zone and becoming a 
potential ignition source in the right main tank, potentially 
resulting in a fuel tank explosion and consequent loss of the 
airplane.

Compliance

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

Install Dam Assembly

    (f) Within 60 months after the effective date of this AD, 
install a dam assembly for the container of the fuel boost pump of 
the center tank located in the right main tank, and do the related 
investigative and applicable corrective actions, by accomplishing 
all the actions specified in the Accomplishment Instructions of 
Boeing Service Bulletin DC9-28-216, dated March 18, 2008. Do the 
applicable corrective actions before further flight.

Alternative Methods of Compliance (AMOCs)

    (g)(1) The Manager, FAA, Los Angeles Aircraft Certification 
Office, ATTN: William S. Bond, Aerospace Engineer, Propulsion 
Branch, ANM-140L, FAA, Los Angeles Aircraft Certification Office, 
3960 Paramount Boulevard, Lakewood, California 90712-4137; telephone 
(562) 627-5253; 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,

[[Page 44939]]

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 July 23, 2008.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E8-17620 Filed 7-31-08; 8:45 am]

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