Document ID: FAA-2007-28281-0013
Agency: faa
Document Type: Rule
Title: Airworthiness Directives; Boeing Model 767 Airplanes
Posted Date: 2009-11-09T05:00Z

[Federal Register: November 9, 2009 (Volume 74, Number 215)]
[Rules and Regulations]               
[Page 57571-57574]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr09no09-5]                         

[[Page 57571]]

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

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-28281; Directorate Identifier 2006-NM-238-AD; 
Amendment 39-16076; AD 2009-23-04]
RIN 2120-AA64

 
Airworthiness Directives; Boeing Model 767 Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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

SUMMARY: We are adopting a new airworthiness directive (AD) for all 
Boeing Model 767 airplanes. This AD requires repetitive replacement of 
the internal electrical feed-through connectors of the boost pumps of 
the main fuel tank. This AD results from a report of cracking in the 
epoxy potting compound on the internal feed-through connector of the 
fuel boost pump in the area of the soldered wire connector lugs. We are 
issuing this AD to prevent a hazardous electrical path from the dry 
side to the wet side of the fuel boost pump through a cracked feed-
through connector, or between pins or a pin and the shell on one side 
of the feed-through connector, which could create an ignition source on 
the wet side of the fuel boost pump or cause a fire in the fuel pump 
enclosure and lead to subsequent explosion of the fuel tank.

DATES: This AD is effective December 14, 2009.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in the AD as of December 14, 
2009.

ADDRESSES: For service information identified in this 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.

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 AD, the regulatory evaluation, 
any comments received, and other information. The address for the 
Docket Office (telephone 800-647-5527) is the Document Management 
Facility, U.S. Department of Transportation, Docket Operations, M-30, 
West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., 
Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Judy Coyle, Aerospace Engineer, 
Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification 
Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone 
(425) 917-6497; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION: 

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 to include an airworthiness directive (AD) that would apply to 
all Boeing Model 767 airplanes. That NPRM was published in the Federal 
Register on May 25, 2007 (72 FR 29282). That NPRM proposed to require 
repetitive replacement of the internal electrical feed-through 
connectors of the boost pumps of the main fuel tank.

Comments

    We gave the public the opportunity to participate in developing 
this AD. We considered the comments received.

Support for the AD

    Continental Airlines states that it has accomplished the actions 
required by the NPRM on all affected airplanes; we infer from this 
statement that Continental concurs with the content of the NPRM.

Request To Withdraw AD

    Boeing suggests that we should not issue the AD, not only because 
the risk is not to the wet tank side, as stated in the NPRM, but also 
in anticipation of the fact that an AD will soon be issued to require 
protection of the fuel boost pumps from electrical threats through 
implementing a ground fault interrupter (GFI) on fuel boost pump 
installations. Boeing adds that affected Model 767 GFI relays have been 
qualified, and Boeing issued Service Bulletin 767-28A0085, dated 
January 10, 2008; and Revision 1, dated June 25, 2009; which include 
procedures for the pump relay removal and replacement.
    Although we understand Boeing's concern, we do not agree to 
withdraw the NPRM. The installation of GFI circuit protection is a 
significant design improvement to prevent repetitive and prolonged 
arcing due to an electrical fault; however, GFI circuit protection does 
not eliminate the potential for an electrical fault to create an 
ignition source at the time the fault initially occurs. The potential 
ignition sources resulting from any single failure in the fuel tanks 
must be fully mitigated by design change or other acceptable means, 
e.g., repetitive inspections, or life-limited parts. The implementation 
of GFI circuit protection provides partial mitigation for this 
particular design problem, and it provides at least partial mitigation 
for electrical failure modes that may not have been identified. 
However, we have determined that it is necessary to require a specific 
action to eliminate the ignition threat presented by this connector 
failure issue, in addition to eventually adding GFI circuit protection. 
We took a similar position on the fuel boost pump power supply conduits 
and fuel tank float switch conduits affecting certain other Boeing 
airplanes. Due to these factors, we have determined that this AD must 
be issued without further delay.

Requests To Change Compliance Time

    ABX Air asks that the limits (compliance times) required by 
paragraphs (f) and (g) of the NPRM be specified in pump hours and 
calendar time relating to an installed pump, and not airframe hours and 
calendar time relating to the airframe. ABX Air states that safe 
operation of the fuel boost pump will be ensured by a 40,000-flight-
hour pump replacement interval, and an interval of 96 months while the 
pump is installed on the wing. ABX Air adds that the calendar-based 
replacement interval is vague and could be misinterpreted; the 96-month 
interval could start when the feed-through connector is manufactured or 
installed in a pump in a repair shop, or when the pump is installed on 
the airplane. ABX Air notes that determining and tracking the 
manufacture date of the connectors would be a burdensome task for 
operators and would change the scope of the NPRM and necessitate 
issuance of a supplemental NPRM. ABX Air states that unless there is 
proof that the connector's epoxy develops cracks while in storage, the 
calendar time should include/consider the time when the pump is 
installed on the airplane. ABX Air adds that the intent of these 
actions should be clarified.
    Japan Airlines (JAL) asks that we clarify the compliance time 
specified in the NPRM for replacement of the feed-through connector to 
specify that the interval is related to in-service operating time. JAL 
notes that it started fuel boost pump replacements during maintenance, 
before the referenced service information was issued. JAL adds that a 
maintenance records review of the pumps should be added to the 
compliance time to confirm previous replacement of the connector.
    All Nippon Airways (ANA) asks that the compliance time specified in 
the

[[Page 57572]]

NPRM for replacement of the fuel boost pump on which the feed-through 
connector was replaced prior to issuance of the referenced service 
information be extended to 96 months or 40,000 flight hours after 
connector replacement.
    UAL recommends that we consider the date of manufacture or total 
in-service hours of the pump for the compliance time in paragraphs (f) 
and (g) of the NPRM. UAL states that although the proposed compliance 
time pertains to the airplane, the FAA intention is to limit the time 
in service of the component feed-through connector to 96 months or 
40,000 flight hours, whichever comes first. UAL adds that pumps older 
than 96 months or having more than 40,000 hours' time-in-service could 
be available; however, it is possible that airplanes having less than 
96 months or 40,000 total flight hours will have these high-time pumps 
installed. UAL states that this will result in the pumps continuing to 
be used beyond the 96-month or 40,000-flight-hour compliance time 
recommended in the NPRM, without having the feed-through connector 
replaced.
    We agree with the commenters. We do not have supporting data to 
show that deterioration of the feed-through connector leading to 
cracking begins at manufacture; such deterioration could result from 
aging of the material. We consider it more likely that the cracking is 
due to the changes in pump temperature that occur with each flight 
during normal operation, and/or vibration of the fuel boost pump during 
operation. However, potted connectors have a longer life in more benign 
operating environments. We have changed the compliance times in 
paragraphs (f) and (g) of this AD so that the compliance times are 
based on the time accrued since installation of a fuel boost pump after 
the feed-through connector is replaced. This can be determined through 
a maintenance records review or, optionally, based on the date the 
connector was replaced.
    In addition, we have re-organized paragraph (g) of this AD and 
added paragraph (h) of this AD for clarity. We have revised the 
subsequent paragraph identifiers accordingly.

Request To Clarify Paragraph (h) of the NPRM

    ABX Air asks that we revise the NPRM to clarify the parts 
installation information specified in paragraph (h) of the NPRM. ABX 
states that, to comply with paragraph (h) of the NPRM, the connector 
must be replaced with a new connector any time a pump is removed and 
reinstalled. ABX notes that a pump could be removed for maintenance 
action unrelated to the internal connector, and the removed pump may 
have had a new connector installed 10,000 flight hours prior to 
removal. ABX adds that to comply with the actions in paragraph (h), the 
pump cannot be reinstalled without replacing the internal connector 
with a new connector, even though the connector has not exceeded the 
40,000-flight-hour limit. ABX Air suggests that the parts installation 
requirements in paragraph (h) be changed for clarification.
    We agree that paragraph (i) of this AD (referred to as paragraph 
(h) in the NPRM) should be further clarified in light of the previously 
identified changes we made to paragraphs (f) and (g) of this AD. We 
have clarified the parts installation information specified in 
paragraph (i) accordingly.

Request To Perform Actions in Paragraph (g) of the NPRM at Different 
Times

    JAL asks that we allow replacement of the feed-through connector in 
the pumps on the left and right main fuel tanks to be done at different 
times, and asks that an informational note be added to the NPRM to 
include this language. JAL provides no justification for its request.
    We infer that JAL would like more flexibility in maintaining its 
airplanes, and we agree that replacement of the connectors in 
individual fuel pumps can be done separately. We have added a new Note 
1 to the AD indicating that it is acceptable to replace the connectors 
in different pumps at different times, provided the compliance times 
required by paragraph (f) of this AD are met for each pump.

Request To Change Unsafe Condition

    Boeing asks that we change the description of the unsafe condition 
in the Summary and Discussion sections of the NPRM, which read as 
follows:

    We are proposing this AD to prevent a hazardous electrical path 
from the dry side to the wet side of the fuel boost pump through a 
cracked feed-through connector, which could create an ignition 
source on the wet side of the fuel boost pump and lead to subsequent 
explosion of the fuel tank.

    Boeing requests that we change the unsafe condition to the 
following:

    We are proposing this AD to address a concern with the existence 
of epoxy potting cracks in the dry side area of the soldered wire 
connector lugs on the feed-through connector. Cracked epoxy on the 
feed-through connector can create an area for conductive debris to 
accumulate that could lead to an ignition source in the Flammable 
Leakage Zone (FLZ) which is the dry site of the pump installation.

    Boeing states that the change to the description of the unsafe 
condition would align the description with that contained in Boeing 
Alert Service Bulletins 767-28A0095 and 767-28A0096, for consistency. 
Boeing adds that the failure does not propagate to the wet side of the 
pump, and the wet side is designed to contain ignition sources.
    We partially agree with the commenter. We agree that clarification 
of the unsafe condition is appropriate because a fire external to the 
fuel boost pump enclosure is also a concern, and may be the more likely 
failure scenario. We disagree that external fire is the only risk 
associated with this design problem. Cracking of the connector potting 
material can eventually lead to corrosion, or a collection of 
contaminants that creates a conductive path between the wet and dry 
sides of the pump connector. If the fuel boost pump is operated under 
dry conditions, such as a forward boost pump during a go-around 
condition, or during defueling on the ground, an ignition source could 
occur inside the pump, resulting in ignition of fuel tank vapor. In 
addition, a leak of the connector due to cracking, combined with an 
ignition source due to a conductive path, could lead to a fire in the 
aluminum pump housing. A fire could cause an ignition source due to 
burn-through or a hot spot on the housing or the wiring conduit. We 
have changed the description of the unsafe condition in the Summary 
section and paragraph (d) of this AD to include some of the commenter's 
suggestions. The Discussion section of the NPRM is not restated in the 
final rule.

Request To Remove Interim Action

    Boeing states that this AD is final action because the combination 
of life limits on the connector and eventual installation of ground-
fault circuit protection provides an acceptable level of safety. Boeing 
notes that no activity is under way regarding redesign of the feed-
through connector, and adds that no additional rulemaking is necessary 
at this time.
    We agree with the commenter's request. We have evaluated the 
information provided, and we have removed the Interim Action paragraph 
in this AD. However, if further necessary action is later identified, 
we might consider further rulemaking then.

Request To Extend Grace Period

    Delta Airlines asks that the grace period required by paragraph 
(f)(2) of the NPRM be extended to 36 months to coincide with the 
deadline for AD 2007-04-16, amendment 39-14948 (72

[[Page 57573]]

FR 7572, February 16, 2007). Delta adds that allowing the extension 
would better coordinate the maintenance between the NPRM and AD 2007-
04-16.
    We disagree with the commenter's request. AD 2007-04-16 was not 
identified in the NPRM as a related AD because those actions are not 
dependent upon the actions required by this AD. Replacing a fuel boost 
pump with a pump that has a new connector can be done during an 
overnight out-of-service period. In developing the 24-month compliance 
time for this AD action, we considered not only the safety implications 
of the identified unsafe condition, but the average utilization rate of 
the affected fleet, and the practical aspects of an orderly 
modification of the fleet during regular maintenance periods. In 
addition, we considered the manufacturer's recommendation for an 
appropriate compliance time. We have made no change to the AD in this 
regard.

Request To Change Paragraph (g)(2) of the NPRM

    ANA states that the feed-through connector replacement was 
recommended in a preliminary revision of the referenced service 
information, but the re-identification method was not. ANA has replaced 
several fuel boost pumps but has not yet done the re-identification. 
ANA notes that, for this reason, the words ``and re-identified'' should 
be deleted from paragraph (g)(2) of the AD. ANA adds that if those 
words are left in that paragraph, a new optional paragraph should be 
added with the following compliance time: ``Within 96 months since the 
last replacement date of feed-through connector or before the 
accumulation of 40,000 flight hours after the last replacement of feed-
through connector, whichever comes first.''
    We do not agree with the commenter's requests. As noted previously, 
we have changed the compliance times in paragraphs (f) and (g) of this 
AD to set life limits based on the time accrued. Further, we consider 
re-identifying the pumps to be important for tracking the status of the 
fuel boost pumps. However, if operators have adequate maintenance 
records for the pumps, and a program is in place to ensure that feed-
through connector replacements are done in a timely manner and endorsed 
by the FAA, we would consider a request for approval of an alternative 
method of compliance (AMOC) to the AD requirements according to the 
provisions of paragraph (j) of this AD. We have made no change to the 
AD in this regard.

Conclusion

    We reviewed the relevant data, considered the comments received, 
and determined that air safety and the public interest require adopting 
the AD with the changes described previously. We also determined that 
these changes will not increase the economic burden on any operator or 
increase the scope of the AD.

Costs of Compliance

    There are about 941 airplanes of the affected design in the 
worldwide fleet. This AD affects about 414 airplanes of U.S. registry, 
at an average labor rate of $80 per work hour.
    The fuel boost pump replacement will take about 3 work hours per 
boost pump (4 boost pumps per airplane) or up to 12 work hours per 
airplane, per replacement cycle. The parts cost for replacement fuel 
boost pumps will be offset by returning the existing fuel boost pumps 
to the manufacturer for rework. Based on these figures, the estimated 
cost of the AD for U.S. operators to replace the fuel boost pumps is up 
to $397,440, or up to $960 per airplane, per replacement cycle.
    The feed-through connector replacement will take about 3 work hours 
per connector (4 connectors per airplane) or up to 12 work hours per 
airplane, per replacement cycle. Required parts will cost $691 per 
connector (up to $2,764 per airplane). Based on these figures, the 
estimated cost of the AD for U.S. operators to replace the feed-through 
connectors is up to $1,541,736, or up to $3,724 per airplane, per 
replacement cycle.

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

    This AD will not have federalism implications under Executive Order 
13132. This AD will 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 this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Is not a ``significant rule'' under 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, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The FAA amends Sec.  39.13 by adding the following new AD:

2009-23-04 Boeing: Amendment 39-16076. Docket No. FAA-2007-28281; 
Directorate Identifier 2006-NM-238-AD.

Effective Date

    (a) This airworthiness directive (AD) is effective December 14, 
2009.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to all Boeing Model 767-200, -300, -300F, 
and -400ER series airplanes, certificated in any category.

Unsafe Condition

    (d) This AD results from a report of cracking in the epoxy 
potting compound on the internal feed-through connector of the fuel 
boost pump in the area of the soldered wire connector lugs. We are 
issuing this AD to prevent a hazardous electrical path from the dry 
side to the wet side of the fuel boost

[[Page 57574]]

pump through a cracked feed-through connector, or between pins or a 
pin and the shell on one side of the feed-through connector, which 
could create an ignition source on the wet side of the fuel boost 
pump or cause a fire in the fuel boost pump enclosure and lead to 
subsequent explosion of the fuel tank.

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.

Compliance Times for Initial Replacement

    (f) For each main tank fuel boost pump: At the latest of the 
times specified in paragraphs (f)(1), (f)(2), and (f)(3) of this AD, 
do the actions specified in paragraph (g) of this AD, in accordance 
with the Accomplishment Instructions of Boeing Alert Service 
Bulletin 767-28A0095 or 767-28A0096; both dated September 15, 2005; 
as applicable.
    (1) Within 96 months since the date of the first installation of 
the fuel boost pump or before the accumulation of 40,000 flight 
hours on the fuel boost pump, whichever comes first.
    (2) Within 96 months since the date of replacement of the feed-
through connector, or before the accumulation of 40,000 flight hours 
on the fuel boost pump since the date of replacement of the feed-
through connector, whichever comes first.
    (3) Within 24 months after the effective date of this AD.

Replacement of Fuel Boost Pump Feed-Through Connector

    (g) At the compliance time specified in paragraph (f) of this 
AD: Replace the feed-through connector of each fuel boost pump as 
described in paragraph (g)(1) or (g)(2) of this AD.
    (1) Replace the fuel boost pump with a new fuel boost pump.
    (2) Replace the fuel boost pump with a modified and re-
identified fuel boost pump having a new feed-through connector 
installed.

    Note 1: Replacing the feed-through connector of each fuel boost 
pump, as required by paragraph (g) of this AD, may be done in 
different fuel boost pumps at different times provided the 
compliance times required by paragraph (f) of this AD are met for 
each pump.

    Note 2: Boeing Alert Service Bulletins 767-28A0095 and 767-
28A0096, both dated September 15, 2005, refer to Hamilton Sundstrand 
Alert Service Bulletin 5006003-28-A4, dated May 9, 2005, as a source 
of guidance for replacing the feed-through connector and re-
identifying the fuel boost pump.

Repetitive Replacements

    (h) Repeat the replacement required by paragraph (g) of this AD 
thereafter at intervals not to exceed the applicable times specified 
in paragraphs (h)(1) and (h)(2) of this AD:
    (1) For airplanes on which the replacement specified in 
paragraph (g)(1) of this AD is done: Within 96 months since the date 
of the first installation of the fuel boost pump or before the 
accumulation of 40,000 flight hours on the fuel boost pump, 
whichever comes first.
    (2) For airplanes on which the replacement specified in 
paragraph (g)(2) of this AD is done: Within 96 months since the date 
of replacement of the feed-through connector or before the 
accumulation of 40,000 flight hours on the fuel boost pump since the 
date of replacement of the feed-through connector, whichever comes 
first.

Parts Installation

    (i) As of the effective date of this AD, no person may install a 
fuel boost pump on any airplane, unless that pump has a feed-through 
connector that meets the requirements of paragraphs (f) and (g) of 
this AD.

Alternative Methods of Compliance (AMOCs)

    (j)(1) The Manager, Seattle Aircraft Certification Office (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 Judy 
Coyle, Aerospace Engineer, Propulsion Branch, ANM-140S, FAA, Seattle 
Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, 
Washington 98057-3356; telephone (425) 917-6497; 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.

Material Incorporated by Reference

    (k) You must use Boeing Alert Service Bulletin 767-28A0095, 
dated September 15, 2005; or Boeing Alert Service Bulletin 767-
28A0096, dated September 15, 2005; as applicable; to do the actions 
required by this AD, unless the AD specifies otherwise.
    (1) The Director of the Federal Register approved the 
incorporation by reference of this service information under 5 
U.S.C. 552(a) and 1 CFR part 51.
    (2) For service information identified in this 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.
    (3) You may review copies of the 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.
    (4) You may also review copies of the service information that 
is incorporated by reference at the National Archives and Records 
Administration (NARA). For information on the availability of this 
material at NARA, call 202-741-6030, or go to: http://
www.archives.gov/federal_register/code_of_federal_regulations/
ibr_locations.html.

    Issued in Renton, Washington, on October 26, 2009.
Stephen P. Boyd,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E9-26585 Filed 11-6-09; 8:45 am]

BILLING CODE 4910-13-P