[Federal Register Volume 70, Number 124 (Wednesday, June 29, 2005)]
[Proposed Rules]
[Pages 37293-37296]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-12840]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-21701; Directorate Identifier 2005-NM-086-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747 and 767 Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for certain Boeing Model 747 and 767 airplanes. This proposed AD would 
require reworking the electrical bonding between the airplane structure 
and the pump housing of the outboard boost pumps in the main fuel tank 
of certain Boeing Model 747 airplanes, and between the airplane 
structure and the pump housing of the override/jettison pumps in the 
left and right wing center auxiliary fuel tanks of certain Boeing Model 
767 airplanes. This proposed AD would also require related 
investigative actions and corrective actions if necessary. This 
proposed AD is prompted by the results of fuel system reviews conducted 
by the manufacturer. We are proposing this AD to prevent insufficient 
electrical bonding, which could result in a potential of ignition 
sources inside the fuel tanks, and 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 15, 2005.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD.
     DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility, U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, room PL-401, 
Washington, DC 20590.
     By fax: (202) 493-2251.
     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street, SW., Washington, DC, 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, P.O. Box 3707, Seattle, Washington 98124-
2207.
    You can examine the contents of this AD docket on the Internet at 
http://dms.dot.gov, or in person at the Docket Management Facility, 
U.S. Department of Transportation, 400 Seventh Street SW., room PL-401, 
on the plaza level of the Nassif Building, Washington, DC. This docket 
number is FAA-2005-21701; the directorate identifier for this docket is 
2005-NM-086-AD.

FOR FURTHER INFORMATION CONTACT: Diane Pagel, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-
4056; telephone (425) 917-6488; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to submit any relevant written data, views, or 
arguments regarding this proposed AD. Send your comments to an address 
listed under ADDRESSES. Include ``Docket No. FAA-2005-21701; 
Directorate Identifier 2005-NM-086-AD'' in the subject line of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the proposed AD. We will 
consider all comments submitted by the closing date and may amend the 
proposed AD in light of those comments.
    We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this proposed AD. Using the search function of 
that Web

[[Page 37294]]

site, anyone can find and read the comments in any of our dockets, 
including the name of the individual who sent the comment (or signed 
the comment on behalf of an association, business, labor union, etc.). 
You can review DOT's complete Privacy Act Statement in the Federal 
Register published on April 11, 2000 (65 FR 19477-78), or you can visit 
http://dms.dot.gov.

Examining the Docket

    You can examine the AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Management Facility office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The Docket Management Facility office (telephone (800) 647-
5227) is located on the plaza level of the Nassif Building at the DOT 
street address stated in the ADDRESSES section. Comments will be 
available in the AD docket shortly after the Docket Management System 
(DMS) receives them.

Discussion

    The FAA has examined the underlying safety issues involved in 
recent 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'' (67 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 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 received a report indicating that the outboard boost pumps 
in the main fuel tank of certain Boeing Model 747 airplanes, and the 
override/jettison pumps in the left and right wing center auxiliary 
fuel tanks of certain Boeing Model 767 airplanes, have insufficient 
electrical bonding between the pump housing and the airplane structure. 
This condition, if not corrected, could result in an ignition source 
inside the fuel tanks, which, in combination with flammable fuel 
vapors, could result in fuel tank explosions and consequent loss of the 
airplane.

Relevant Service Information

    We have reviewed Boeing Special Attention Service Bulletin 747-28-
2259, dated November 4, 2004 (for Boeing Model 747-100, 747-100B, 747-
100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 
747-400F, 747SR, and 747SP series airplanes). This service bulletin 
describes procedures for reworking the electrical bonding between the 
airplane structure and the pump housing of the outboard boost pumps in 
the main fuel tank, and related investigative and corrective actions. 
The rework consists of replacing the four mounting fasteners on each of 
the pump housings with rivets, stenciling each new rivet with the 
statement: ``CAUTION--BONDING RIVET,'' and, when the related 
investigative actions are completed, sealing the new rivets as 
specified in the airplane maintenance manual. The related investigative 
actions are measuring the electrical resistance of the new rivets, and 
doing an open-hole high-frequency eddy current (HFEC) inspection for 
cracks, corrosion, and damage. If the resistance is greater than the 
maximum allowable resistance specified in the service bulletin, the 
procedures include reworking the bonding as necessary according to the 
standard wiring practices manual, until the resistance is within 
allowable limits.
    We have also reviewed Boeing Special Attention Service Bulletin 
767-57-0092, dated November 4, 2004 (for Boeing Model 767-200, -300, 
and -300F series airplanes); and Boeing Special Attention Service 
Bulletin 767-57-0093, dated November 4, 2004 (for Boeing Model 767-
400ER series airplanes). These service bulletins describe procedures 
for reworking the electrical bonding between the airplane structure and 
the pump housing of the override/jettison pumps in the left and right 
wing center auxiliary fuel tanks, and related investigative actions and 
corrective actions. The rework consists of cleaning the wing rib/ground 
bracket bonding surface, installing new fasteners for the ground 
brackets of the fuel override/jettison pump, using new bonding 
processes during the installation, and sealing the ground brackets. The 
related investigative actions are measuring the electrical resistance 
at specified points in the re-work process. If the electrical 
resistance is greater than the maximum allowable resistance specified 
in the service bulletin, the corrective action specified in the 
procedures includes repeating the applicable corrective actions and the 
applicable related investigative actions until the resistance is within 
allowable limits.
    Accomplishing the actions specified in the service information is 
intended to adequately address the unsafe condition.

FAA's Determination and Requirements of the Proposed AD

    We have evaluated all pertinent information and identified an 
unsafe condition that is likely to exist or develop on other airplanes 
of this same type design. Therefore, we are proposing this AD, which 
would require accomplishing the actions specified in the service 
information described previously, except as discussed under 
``Difference Between the Proposed AD and Special Attention Service 
Bulletin 747-28-2259.''

Difference Between the Proposed AD and Special Attention Service 
Bulletin 747-28-2259

    Although Boeing Special Attention Service Bulletin 747-28-2259 does 
not specify an action to take if any crack, corrosion, or damage is 
found during the open-hole HFEC inspection, this proposed AD would 
require operators to repair those conditions in one of the following 
ways:
     Using a method that we approve; or

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     Using data that meet the certification basis of the 
airplane, and that have been approved by an Authorized Representative 
for the Boeing Delegation Option Authorization Organization whom we 
have authorized to make those findings.

Costs of Compliance

    There are about 3,401 airplanes of the affected design in the 
worldwide fleet. The following table provides the estimated costs for 
U.S. operators to comply with this proposed AD.

                                                 Estimated Costs
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                                                                                  Number of U.S.-
             Action                  Work hour     Average labor     Cost per       registered      Fleet cost
                                                  rate pere hour     airplane        airplanes
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Rework electrical bonding for                 10             $65            $650           1,115        $724,750
 Boeing Model 747 airplanes.....
Rework electrical bonding for                  9              65             585             921         538,785
 Boeing Model 767 airplanes.....
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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 have 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 that the 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.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this proposed AD. See the ADDRESSES section for a location 
to examine the regulatory evaluation.

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 
airworthiness directive (AD):

Boeing: Docket No. FAA-2005-21701; Directorate Identifier 2005-NM-
086-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this AD action by August 15, 2005.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to the Boeing airplane models identified in 
Table 1 of this AD, certificated in any category.

                 Table 1.--Airplanes Affected by This AD
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                                         As identified in Boeing special
                Model--                    attention service bulletin--
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747-100, 747-100B, 747-100B SUD, 747-    747-28-2259, dated November 4,
 200B, 747-200C, 747-200F, 747-300, 747-  2004.
 400, 747-400D, 747-400F, 747SR, and
 747SP series airplanes.
767-200, -300, and -300F series          767-57-0092, dated November 4,
 airplanes.                               2004.
767-400ER series airplanes.............  767-57-0093, dated November 4,
                                          2004.
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Unsafe Condition

    (d) This AD was prompted by the results of fuel system reviews 
conducted by the manufacturer. We are issuing this AD to prevent 
insufficient electrical bonding, which could result in a potential 
of ignition sources inside the fuel tanks, and which, in combination 
with flammable fuel vapors, could result in fuel tank explosions and 
consequent loss of the airplane.

Compliance

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

Rework Electrical Bonding

    (f) Within 60 months after the effective date of this AD: Do the 
actions specified in paragraph (f)(1) or (f)(2) of this AD, as 
applicable, by accomplishing all the actions specified in the 
Accomplishment Instructions of the applicable service bulletin in 
Table 1 of this AD. Do any related investigative and corrective 
actions before further flight.
    (1) For Boeing Model 747-100, 747-100B, 747-100B SUD, 747-200B, 
747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 747SR, and 
747SP series airplanes: Rework the electrical bonding between the 
airplane structure and the pump housing of the outboard boost pumps 
in the main fuel tank, and do related investigative and

[[Page 37296]]

applicable corrective actions. If any crack, corrosion, or damage is 
found during the open-hole high-frequency eddy current inspection 
specified in Boeing Special Attention Service Bulletin 747-28-2259, 
dated November 4, 2004: Before further flight, repair in accordance 
with a method approved by the Manager, Seattle Aircraft 
Certification Office (ACO), FAA; or in accordance with data meeting 
the certification basis of the airplane approved by an Authorized 
Representative for the Boeing Delegation Option Authorization 
Organization who has been authorized by the Manager, Seattle ACO, to 
make those findings. For a repair method to be approved, the 
approval must specifically reference this AD.
    (2) For Boeing Model 767-200, -300, -300F, and -400ER series 
airplanes: Rework the electrical bonding between the airplane 
structure and the pump housing of the override/jettison pumps in the 
left and right wing center auxiliary fuel tanks, and do the related 
investigative and applicable corrective actions.

Alternative Methods of Compliance (AMOCs)

    (g) The Manager, Seattle ACO, FAA, has the authority to approve 
AMOCs for this AD, if requested in accordance with the procedures 
found in 14 CFR 39.19.

    Issued in Renton, Washington, on June 21, 2005.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 05-12840 Filed 6-28-05; 8:45 am]
BILLING CODE 4910-13-P