Document ID: FAA-2008-0978-0001
Agency: faa
Document Type: Rule
Title: Airworthiness Directives; Boeing Model 767-200, -300, and -300F Series Airplanes
Posted Date: 2009-07-02T04:00Z

[Federal Register: July 2, 2009 (Volume 74, Number 126)]
[Proposed Rules]               
[Page 31640-31642]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr02jy09-10]                         

========================================================================
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.

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[[Page 31640]]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-0978; Directorate Identifier 2008-NM-014-AD]
RIN 2120-AA64

 
Airworthiness Directives; Boeing Model 767-200, -300, and -300F 
Series Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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

SUMMARY: We propose to adopt a new airworthiness directive (AD) for 
certain Boeing Model 767-200, -300, and -300F series airplanes. For 
certain airplanes, this proposed AD would require modifying the fuel 
quantity indicating system (FQIS) densitometer. For certain other 
airplanes, this proposed AD would require replacing the existing hot 
short protector (HSP) on the FQIS densitometer with a new HSP. The 
proposed AD would also require revising the Airworthiness Limitations 
(AWL) section of the Instructions for Continued Airworthiness to 
incorporate AWL No. 28-AWL-22. This proposed AD results from fuel 
system reviews conducted by the manufacturer. We are proposing this AD 
to prevent the center tank fuel densitometer from overheating and 
becoming a potential ignition source inside the center fuel tank, 
which, in combination with flammable fuel vapors, could result in a 
center fuel tank explosion and consequent loss of the airplane.

DATES: We must receive comments on this proposed AD by August 17, 2009.

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, 
P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone 206-
544-5000, extension 1, fax 206-766-5680; e-mail me.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 or 
425-227-1152.

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: Georgios Roussos, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-
3356; telephone (425) 917-6482; fax (425) 917-6590.

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-2008-0978; 
Directorate Identifier 2008-NM-014-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

[[Page 31641]]

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 found that no separation was provided for the fuel quantity 
indication system (FQIS) wires. A potential hot short of the FQIS lead 
wire would cause the center fuel tank densitometer to overheat. In 
situations where the fuel level in the center tank is low, the 
overheated densitometer could ignite flammable fuel vapors inside the 
center fuel tank. This condition, if not corrected, could result in a 
center fuel tank explosion and consequent loss of the airplane.

Other Related Rulemaking

    On May 8, 2008, we issued AD 2008-11-01, amendment 39-15523 (73 FR 
29414, May 21, 2008), applicable to certain Boeing Model 767-200, -300, 
-300F, and -400ER series airplanes. That AD requires revising the 
Airworthiness Limitations (AWL) section of the Instructions for 
Continued Airworthiness to incorporate new AWLs for fuel tank systems 
to satisfy Special Federal Aviation Regulation No. 88 requirements. 
That AD resulted from a design review of the fuel tank systems. We 
issued that 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. Incorporating AWL No. 28-AWL-22 into the FAA-approved 
maintenance program in accordance with paragraph (g)(2) of AD 2008-11-
01 would terminate the action specified in paragraph (h) of this 
proposed AD.

Relevant Service Information

    We have reviewed Boeing Service Bulletin 767-28A0094, Revision 1, 
dated April 23, 2009. For Group 1 airplanes, Group 2 airplanes, 
Configuration 1, and Group 3 airplanes, the service bulletin describes 
procedures for modifying the FQIS densitometer. The modification 
includes installing new hot short protector (HSP) support brackets and 
grounding brackets, installing a HSP and bonding jumper, rerouting 
certain wire bundles, and installing new wire bundles. Group 2 
airplanes, Configuration 2, on which Boeing Service Bulletin 767-28-
0043 has not been incorporated, will have the Honeywell densitometer 
installed; therefore, no work is necessary. For Group 4 airplanes, the 
service bulletin describes procedures for replacing the existing HSP 
with a new HSP.
    We have reviewed Revision March 2009 of Section 9 (``AIRWORTHINESS 
LIMITATIONS (AWLs) AND CERTIFICATION MAINTENANCE REQUIREMENTS (CMRs)'') 
of the Boeing 767 Maintenance Planning Data (MPD) Document, D622T001-9 
(hereafter referred to as ``the MPD'') of the MPD, which describes AWLs 
for fuel tank systems. The MPD includes fuel system AWL No. 28-AWL-22, 
which is a critical design configuration control limitation (CDCCL) to 
maintain the design features of the center fuel tank HSP during its 
replacement.

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 same type design. 
This proposed AD would require the following actions:
     Modifying the FQIS densitometer for certain airplanes, and 
replacing the existing HSP with a new HSP for certain other airplanes.
     Revising the FAA-approved maintenance program to 
incorporate AWL No. 28-AWL-22, which would require maintaining the 
design features of the center fuel tank HSP during its replacement.

Costs of Compliance

    We estimate that this proposed AD would affect 192 airplanes of 
U.S. registry. The following table provides the estimated costs for 
U.S. operators to comply with this proposed AD.

                                                                     Estimated Costs
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                 Number of
                                                        Average  labor                                             U.S.-
Affected airplane  groups/action       Work hours       rate  per hour         Parts         Cost per product    registered           Fleet cost
                                                                                                                 airplanes
--------------------------------------------------------------------------------------------------------------------------------------------------------
Group 1, Group 2, Configuration   Between 4 and 8....              $80  Between $11,377     Between $11,697             191  Between $2,234,127 and
 1, and Group 3, modification.                                           and $14,376.        and $15,016.                     $2,868,056.
Group 4, replacement............  2..................               80  None..............  $160..............            1  $160.
AWL revision....................  1..................               80  None..............  $80...............          192  $15,360.
--------------------------------------------------------------------------------------------------------------------------------------------------------

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:

[[Page 31642]]

    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, 
Incorporation by Reference.

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:

Boeing: Docket No. FAA-2008-0978; Directorate Identifier 2008-NM-
014-AD.

Comments Due Date

    (a) We must receive comments by August 17, 2009.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 767-200, -300, and -300F 
series airplanes, certificated in any category; as identified in 
Boeing Service Bulletin 767-28A0094, Revision 1, dated April 23, 
2009.

    Note 1: This AD requires revisions to certain operator 
maintenance documents to include new inspections. Compliance with 
these inspections is required by 14 CFR 91.403(c). For airplanes 
that have been previously modified, altered, or repaired in the 
areas addressed by these inspections, the operator may not be able 
to accomplish the inspections described in the revisions. In this 
situation, to comply with 14 CFR 91.403(c), the operator must 
request approval for an alternative method of compliance (AMOC) 
according to paragraph (k) of this AD. The request should include a 
description of changes to the required inspections that will ensure 
the continued operational safety of the airplane.

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 
densitometer from overheating and becoming a potential ignition 
source inside the center fuel tank, which, in combination with 
flammable fuel vapors, could result in a center fuel tank explosion 
and consequent loss of the airplane.

Compliance

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

Modify the Fuel Quantity Indicating System (FQIS) Densitometer/Replace 
Hot Short Protector (HSP)

    (f) Within 60 months after the effective date of this AD, do the 
actions specified in paragraphs (f)(1) and (f)(2) of this AD, as 
applicable, in accordance with the Accomplishment Instructions of 
Boeing Service Bulletin 767-28A0094, Revision 1, dated April 23, 
2009.
    (1) For Group 1 airplanes, Group 2 airplanes, Configuration 1, 
and Group 3 airplanes: Modify the fuel quantity indicating system 
(FQIS) densitometer.
    (2) For Group 4 airplanes: Replace the existing HSP with a new 
HSP.

Credit for Service Information Accomplished Previously

    (g) Actions done before the effective date of this AD in 
accordance with Boeing Alert Service Bulletin 767-28A0094, dated 
November 20, 2007; are acceptable for compliance with the 
requirements of paragraph (f) of this AD.

Airworthiness Limitations (AWL) Revision

    (h) Concurrently with accomplishing the actions required by 
paragraph (f) of this AD, revise the AWL section of the Instructions 
for Continued Airworthiness by incorporating AWL No. 28-AWL-22 of 
the Boeing 767 Maintenance Planning Data (MPD) Document, D622T001-9, 
Section 9, Revision March 2009.

No Alternative Critical Design Configuration Control Limitations 
(CDCCL)

    (i) After the actions specified in paragraph (g) of this AD have 
been accomplished, no alternative CDCCL for AWL No. 28-AWL-22 may be 
used; unless the CDCCL is approved as an AMOC in accordance with the 
procedures specified in paragraph (k) of this AD.

Terminating Action for AWL Revision

    (j) Incorporating AWL No. 28-AWL-22 into the AWL section of the 
Instructions for Continued Airworthiness in accordance with 
paragraph (g)(2) of AD 2008-11-01, amendment 39-15523, terminates 
the action required by paragraph (h) of this AD.

Alternative Methods of Compliance (AMOCs)

    (k)(1) The Manager, Seattle ACO, 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: Georgios Roussos, 
Aerospace Engineer, Systems and Equipment Branch, ANM-130S, 1601 
Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 
917-6482; fax (425) 917-6590. Or, e-mail information to 9-ANM-
Seattle-ACO-AMOC-Requests@faa.gov.
    (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 24, 2009.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E9-15618 Filed 7-1-09; 8:45 am]

BILLING CODE 4910-13-P