

[Federal Register: January 18, 2008 (Volume 73, Number 13)]
[Proposed Rules]               
[Page 3422-3425]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr18ja08-15]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-0032; Directorate Identifier 2007-NM-314-AD]
RIN 2120-AA64

 
Airworthiness Directives; McDonnell Douglas Model 717-200 
Airplanes; Model DC-9-10 Series Airplanes; Model DC-9-20 Series 
Airplanes; Model DC-9-30 Series Airplanes; Model DC-9-40 Series 
Airplanes; Model 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; Model MD-88 
Airplanes; and Model MD-90-30 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 all 
McDonnell Douglas airplanes identified above. This proposed AD would 
require revising the FAA-approved maintenance program, or the 
Airworthiness Limitations (AWLs) section of the Instructions for 
Continued Airworthiness, as applicable, to incorporate new AWLs for 
fuel tank systems to satisfy Special Federal Aviation Regulation No. 88 
requirements. This proposed AD results from a design review of the fuel 
tank systems. We are proposing this AD to prevent the potential for 
ignition sources inside fuel tanks caused by latent failures, 
alterations, repairs, or maintenance actions, 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 March 3, 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-2008-0032; 
Directorate Identifier 2007-NM-314-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

[[Page 3423]]

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 another 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 proposed AD 
are necessary to reduce the potential of ignition sources inside fuel 
tanks, 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 the following appendixes of the Boeing Twinjet 
Special Compliance Items Report, MDC-92K9145, Revision G, dated June 7, 
2007 (hereafter referred to as ``Report MDC-92K9145''):

 Appendix B, Critical Design Configuration Control Limitations 
(CDCCLs)
 Appendix C, Airworthiness Limitation Instructions (ALIs)
 Appendix D, Short-Term Extensions

Appendixes B and C of Report MDC-92K9145 describe new airworthiness 
limitations (AWLs) for fuel tank systems. The new AWLs include:
     CDCCLs, which are limitation requirements to preserve a 
critical ignition source prevention feature of the fuel tank system 
design that is necessary to prevent the occurrence of an unsafe 
condition. The purpose of a CDCCL is to provide instruction to retain 
the critical ignition source prevention feature during configuration 
change that may be caused by alterations, repairs, or maintenance 
actions. A CDCCL is not a periodic inspection; and
     AWL inspections, which are inspections of certain features 
for latent failures that could contribute to an ignition source.

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 the(se) same type 
design(s). This proposed AD would require revising the FAA-approved 
maintenance program, or the AWLs section of the Instructions for 
Continued Airworthiness, as applicable, by incorporating the 
information in Appendixes B, C, and D of Report MDC-92K9145.

Difference Between the Proposed AD and Service Information

    Although Report MDC-92K9145 specifies to submit certain information 
to the manufacturer, this proposed AD does not include that 
requirement.

Explanation of Compliance Time

    In most ADs, we adopt a compliance time allowing a specified amount 
of time after the AD's effective date. In this case, however, the FAA 
has already issued regulations that require operators to revise their 
maintenance/inspection programs to address fuel tank safety issues. The 
compliance date for these regulations is December 16, 2008. To provide 
for efficient and coordinated implementation of these regulations and 
this proposed AD, we are using this same compliance date in this 
proposed AD.

Rework Required When Implementing AWLs Into an Existing Fleet

    The maintenance program revision specified in paragraph (g) of this 
proposed AD, and the AWLs revision specified in paragraph (h) of this 
proposed AD, for the fuel tank systems, which involve incorporating the 
information specified in Report MDC-92K9145, would affect how operators 
maintain their airplanes. After doing the maintenance program revision 
or AWLs revision, as applicable, operators would need to do any 
maintenance on the fuel tank system as specified in the CDCCLs. 
Maintenance done before the maintenance program revision specified in 
paragraph (g), or the AWLs revision specified in paragraph (h), as 
applicable, would not need to be redone in order to comply with 
paragraph (g) or (h). For example, the AWL that requires fuel pumps to 
be repaired and overhauled per the FAA-approved component maintenance 
manual (CMM) applies to fuel pumps repaired after the maintenance 
programs are revised; spare or on-wing fuel pumps do not need to be 
reworked.

Changes to Fuel Tank System AWLs

    For certain airplanes, paragraph (g) of this proposed AD would 
require revising the FAA-approved maintenance program by incorporating 
certain information specified in Report MDC-92K9145. For certain other 
airplanes, paragraph (h) of this proposed AD would require revising the 
AWLs section of the Instructions for Continued Airworthiness by 
incorporating certain information specified in Report MDC-92K9145. 
Paragraphs (g) and (h) allow accomplishing the revision in accordance 
with later revisions of Report MDC-92K9145 as an acceptable method of 
compliance if they are approved by the Manager, Los Angeles Aircraft 
Certification Office (ACO), FAA. In addition, Appendix B of Report MDC-
92K9145 specifies that any deviations from the published AWL 
instructions, including AWL intervals, must be approved by the Manager, 
Los Angeles ACO. Therefore, after the maintenance program or AWLs 
revision, any further revision to an AWL or AWL interval should be done 
as an AWL change, not as an alternative method of compliance (AMOC). 
For U.S.-registered airplanes, operators must make requests through an 
appropriate FAA Principal Maintenance Inspector (PMI) or Principal 
Avionics Inspector (PAI) for approval by the Manager, Los Angeles ACO. 
A non-U.S. operator should coordinate changes with its governing 
regulatory agency.

Exceptional Short-Term Extensions

    Appendix D of Report MDC-92K9145 has provisions for an exceptional 
short-term extension of 30 days. An exceptional short-term extension is 
an increase in an AWL interval that may be needed to cover an 
uncontrollable or unexpected situation. For U.S.-registered airplanes, 
the FAA PMI or PAI must concur with any exceptional short-term 
extension before it is used, unless the operator has identified another 
appropriate procedure with the local regulatory authority. The FAA PMI 
or PAI may grant the exceptional short-term extensions described in 
Appendix D without consultation with the Manager, Los Angeles ACO. A 
non-U.S. operator should coordinate changes with its governing 
regulatory agency. As explained in Appendix D, exceptional short-term 
extensions must not be used for fleet AWL extensions. An exceptional 
short-term extension should not be confused with an operator's short-
term escalation authorization approved in accordance with the 
Operations Specifications or the operator's reliability program.

[[Page 3424]]

Ensuring Compliance With Fuel Tank System AWLs

    Boeing has revised the applicable maintenance manuals and task 
cards to address AWLs and to include notes about CDCCLs. Operators that 
do not use Boeing's revision service should revise their maintenance 
manuals and task cards to highlight actions tied to CDCCLs to ensure 
that maintenance personnel are complying with the CDCCLs.

Recording Compliance With Fuel Tank System AWLs

    The applicable operating rules of the Federal Aviation Regulations 
(14 CFR parts 91, 121, 125, and 129) require operators to maintain 
records with the identification of the current inspection status of an 
airplane. The AWLs contained in Appendix C of Report MDC-92K9145 are 
inspections for which the applicable sections of the operating rules 
apply. The AWLs contained in Appendix B of Report MDC-92K9145 are 
CDCCLs, which are tied to conditional maintenance actions. An entry 
into an operator's existing maintenance record system for corrective 
action is sufficient for recording compliance with CDCCLs, as long as 
the applicable maintenance manual and task cards identify actions that 
are CDCCLs.

Changes to Component Maintenance Manuals (CMMs) Cited in Fuel Tank 
System AWLs

    Some of the AWLs in Appendix B of Report MDC-92K9145 refer to 
specific revision levels of the CMMs as additional sources of service 
information for doing the AWLs. Boeing is referring to the CMMs by 
revision level in the applicable AWL for certain components rather than 
including information directly in the AWL because of the volume of that 
information. As a result, the Manager, Los Angeles ACO, must approve 
the CMMs. Any later revision of those CMMs will be handled like a 
change to the AWL itself. Any use of parts (including the use of parts 
manufacturer approval (PMA) approved parts), methods, techniques, and 
practices not contained in the CMMs need to be approved by the Manager, 
Los Angeles ACO, or governing regulatory authority. For example, 
certain pump repair/overhaul manuals must be approved by the Manager, 
Los Angeles ACO.

Changes to Airplane Maintenance Manual Referenced in Fuel Tank System 
AWLs

    In other AWLs in Report MDC-92K9145, the AWLs contain all the 
necessary data. The applicable section of the maintenance manual is 
usually included in the AWLs. Boeing intended this information to 
assist operators in maintaining the maintenance manuals. A maintenance 
manual change to these tasks may be made without approval by the 
Manager, Los Angeles ACO, through an appropriate FAA PMI or PAI, by the 
governing regulatory authority, or by using the operator's standard 
process for revising maintenance manuals. An acceptable change would 
have to maintain the information specified in the AWL such as the pass/
fail criteria or special test equipment.

Costs of Compliance

    We estimate that this proposed AD would affect 780 airplanes of 
U.S. registry. We also estimate that it would take about 1 work-hour 
per product to comply with this proposed AD. The average labor rate is 
$80 per work-hour. Based on these figures, we estimate the cost of this 
proposed AD to the U.S. operators to be $62,400, or $80 per product.

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-2008-0032; Directorate Identifier 
2007-NM-314-AD.

Comments Due Date

    (a) We must receive comments by March 3, 2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to all McDonnell Douglas Model 717-200 
airplanes; Model DC-9-11, DC-9-12, DC-9-13, DC-9-14, DC-9-15, and 
DC-9-15F airplanes; Model DC-9-21 airplanes; Model DC-9-31, DC-9-32, 
DC-9-32 (VC-9C), DC-9-32F, DC-9-33F, DC-9-34, DC-9-34F, and DC-9-32F 
(C-9A, C-9B) airplanes; Model DC-9-41 airplanes; Model DC-9-51 
airplanes; Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), 
and DC-9-87 (MD-87) airplanes; Model MD-88 airplanes; and Model MD-
90-30 airplanes; certificated in any category.

    Note 1: This AD requires revisions to certain operator 
maintenance documents to include new inspections and maintenance 
actions. Compliance with these limitations is required by 14 CFR 
43.16 and 91.403(c). For airplanes that have been previously 
modified, altered, or repaired in the areas addressed by these 
limitations, the operator may not be able to accomplish the actions 
described in the revisions. In this situation, to comply with 14 CFR 
43.16 and 91.403(c), the operator must request approval for revision 
to the airworthiness limitations (AWLs) in the Boeing Twinjet 
Special Compliance Items Report, MDC-92K9145, according to paragraph 
(g), (h), or (j) of this AD, as applicable.


[[Page 3425]]



Unsafe Condition

    (d) This AD results from a design review of the fuel tank 
systems. We are issuing this AD to prevent the potential for 
ignition sources inside fuel tanks caused by latent failures, 
alterations, repairs, or maintenance actions, which, in combination 
with flammable fuel vapors, could result 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.

Service Information Reference

    (f) The term ``Report MDC-92K9145,'' as used in this AD, means 
the Boeing Twinjet Special Compliance Items Report, MDC-92K9145, 
Revision G, dated June 7, 2007.

Revise the FAA-Approved Maintenance Program

    (g) For Model DC-9-11, DC-9-12, DC-9-13, DC-9-14, DC-9-15, and 
DC-9-15F airplanes; Model DC-9-21 airplanes; Model DC-9-31, DC-9-32, 
DC-9-32 (VC-9C), DC-9-32F, DC-9-33F, DC-9-34, DC-9-34F, and DC-9-32F 
(C-9A, C-9B) airplanes; Model DC-9-41 airplanes; Model DC-9-51 
airplanes; and Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-
83), and DC-9-87 (MD-87) airplanes: Before December 16, 2008, revise 
the FAA-approved maintenance program to incorporate the information 
specified in Appendixes B, C, and D of Report MDC-92K9145. 
Accomplishing the revision in accordance with a later revision of 
Report MDC-92K9145 is an acceptable method of compliance if the 
revision is approved by the Manager, Los Angeles Aircraft 
Certification Office (ACO), FAA.

Revise the AWLs Section

    (h) For Model 717-200, Model MD-88, and Model MD-90-30 
airplanes: Before December 16, 2008, revise the AWLs section of the 
Instructions for Continued Airworthiness to incorporate the 
information specified in Appendixes B, C, and D of Report MDC-
92K9145. Accomplishing the revision in accordance with a later 
revision of Report MDC-92K9145 is an acceptable method of compliance 
if the revision is approved by the Manager, Los Angeles ACO.

No Reporting Requirement

    (i) Although Report MDC-92K9145 specifies to submit certain 
information to the manufacturer, this AD does not require that 
action.

Alternative Methods of Compliance (AMOCs)

    (j)(1) The Manager, Los Angeles ACO, FAA, ATTN: Serj Harutunian, 
Aerospace Engineer, Propulsion Branch, ANM-140L, 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 January 9, 2008.
Stephen P. Boyd,
Assistant Manager, Transport Airplane Directorate, Aircraft 
Certification Service.
[FR Doc. E8-857 Filed 1-17-08; 8:45 am]

BILLING CODE 4910-13-P
