[Federal Register Volume 71, Number 129 (Thursday, July 6, 2006)]
[Proposed Rules]
[Pages 38304-38311]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-10536]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-20351; Directorate Identifier 2003-NM-269-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 767 Airplanes

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

ACTION: Supplemental notice of proposed rulemaking (NPRM); reopening of 
comment period.

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SUMMARY: The FAA is revising an earlier proposed airworthiness 
directive (AD) for all Boeing Model 767 airplanes. The original NPRM 
would have required an inspection of each main tank fuel boost pump for 
the presence of a pump shaft flame arrestor, and if the flame arrestor 
is missing, replacement of that pump with a pump having a pump shaft 
flame arrestor. The original NPRM would also have required repetitive 
measurements of the flame arrestor's position in the pump, and 
corrective actions if necessary. The original NPRM resulted from 
reports that certain fuel boost pumps may not have flame arrestors 
installed in the pump shaft and reports

[[Page 38305]]

that the pin that holds the flame arrestor in place can break due to 
metal fatigue. This action revises the original NPRM by proposing the 
replacement of the pump with a new or modified pump, which would end 
the repetitive measurements. This action also revises the compliance 
times for certain airplanes. We are proposing this supplemental NPRM to 
prevent the possible migration of a flame from a main tank fuel boost 
pump inlet to the vapor space of that fuel tank, and consequent 
ignition of fuel vapors, which could result in a fire or explosion.

DATES: We must receive comments on this supplemental NPRM by July 31, 
2006.

ADDRESSES: Use one of the following addresses to submit comments on 
this supplemental NPRM.
     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.
     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.
    Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, 
Washington 98124-2207, for service information identified in this 
proposed AD.

FOR FURTHER INFORMATION CONTACT: John Vann, Aerospace Engineer, 
Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification 
Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone 
(425) 917-6513; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to submit any relevant written data, views, or 
arguments regarding this supplemental NPRM. Send your comments to an 
address listed in the ADDRESSES section. Include the docket number 
``FAA-2005-20351; Directorate Identifier 2003-NM-269-AD'' at the 
beginning of your comments. We specifically invite comments on the 
overall regulatory, economic, environmental, and energy aspects of this 
supplemental NPRM. We will consider all comments received by the 
closing date and may amend this supplemental NPRM in light of those 
comments.
    We will post all comments submitted, 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 supplemental NPRM. Using the search function 
of that Web 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 may review the DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR 19477-78), or you 
may visit http://dms.dot.gov.

Examining the Docket

    You may 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 in the Nassif Building at the DOT 
street address stated in ADDRESSES. Comments will be available in the 
AD docket shortly after the Docket Management System receives them.

Discussion

    We proposed to amend 14 CFR part 39 with a notice of proposed 
rulemaking (NPRM) for an AD (the ``original NPRM'') for all Boeing 
Model 767 series airplanes. The original NPRM was published in the 
Federal Register on February 15, 2005 (70 FR 7678). The original NPRM 
proposed to require an inspection of each main tank fuel boost pump for 
the presence of a pump shaft flame arrestor, and if the flame arrestor 
is missing, replacement of that pump with a pump having a pump shaft 
flame arrestor. The original NPRM also proposed to require repetitive 
measurements of the flame arrestor's position in the pump, and 
corrective actions if necessary.

Actions Since Original NPRM Was Issued

    The preamble to the original NPRM explains that we consider the 
proposed requirements ``interim action'' and were considering further 
rulemaking. Since we issued the original NPRM, the manufacturer has 
issued new service information, which specifies actions that terminate 
the repetitive measurements proposed in the original NPRM. This 
supplemental NPRM follows from the determination that the additional 
actions are necessary.

Relevant Service Information

    We have reviewed Boeing Alert Service Bulletins 767-28A0088 (for 
Model 767-200, -300, and -300F series airplanes) and 767-28A0089 (for 
Model 767-400ER series airplanes), both dated February 24, 2005. The 
alert service bulletins describe procedures for replacing the left and 
right main tank fuel boost pumps with new or modified pumps that have a 
better flame arrestor installation. Doing the replacements ends the 
inspections specified in Boeing Alert Service Bulletin 767-28A0077 (for 
Model 767-200, -300, and -300F series airplanes) or 767-28A0081 (for 
Model 767-400ER series airplanes), both Revision 1, both dated July 8, 
2004, as applicable.
    Accomplishing the actions specified in the service information is 
intended to adequately address the unsafe condition.
    Boeing Alert Service Bulletins 767-28A0088 and 767-28A0089 
reference Hamilton Sundstrand Service Bulletin 5006003-28-3, dated 
December 8, 2004, as the appropriate source of service information for 
modifying the pump.

Comments

    We have considered the following comments on the original NPRM.

Support for the Original NPRM

    The Air Line Pilots Association agrees with the original NPRM.

Request To Allow Credit

    ABX Air requests that actions done in accordance with Boeing Alert 
Service Bulletin 767-28A0077, dated March 6, 2003, be accepted as a 
method of compliance with the requirements of the original NPRM. The 
commenter indicates that there are no substantive differences between 
the actions of the original version and Boeing Alert Service Bulletin 
767-28A0077, Revision 1, dated July 8, 2004 (Revision 1 is listed as 
the appropriate source of service information for doing the actions 
specified in paragraph (g) of the original NPRM for Model 767-200, -
300, and -300F series airplanes).
    We agree that any work done before the effective date of the AD in 
accordance with Boeing Alert Service Bulletin 767-28A0077, dated March 
6, 2003, is acceptable for compliance with the actions specified in 
paragraphs (f) and (g) of this supplemental NPRM (specified as 
paragraph (g) in the original NPRM) for Model 767-200, -300, and -300F 
series airplanes. In addition, we have determined that any

[[Page 38306]]

work done before the effective date of the AD in accordance with Boeing 
Alert Service Bulletin 767-28A0081, dated March 6, 2003, is acceptable 
for compliance with the actions specified in paragraphs (f) and (g) of 
this supplemental NPRM for Model 767-400ER series airplanes (Boeing 
Alert Service Bulletin 767-28A0081, Revision 1, dated July 8, 2004, is 
listed as the appropriate source of service information for doing the 
actions specified in paragraph (g) of the original NPRM for Model 767-
400ER series airplanes).
    We have added new paragraph (j) to this supplemental NPRM to give 
credit for actions done before the effective date of the AD in 
accordance with these service bulletins. We have also removed the 
service bulletin reference paragraph from this supplemental NPRM 
(specified as paragraph (f) in the original NPRM) and we have included 
the service bulletin information in paragraphs (f) and (g) of this 
supplemental NPRM (specified as paragraph (g) in the original NPRM).

Request To Add Terminating Action

    ABX Air, Continental Airlines, All Nippon Airways (ANA), UPS, and 
Boeing state that there is now a terminating action for the repetitive 
inspections (measurements) specified in paragraph (g) of original NPRM 
since Boeing has issued Alert Service Bulletins 767-28A0088 and 767-
28A0089, both dated February 24, 2005, which replace the main tank fuel 
boost pumps with new or modified pumps. Several commenters request that 
a statement be added to the original NPRM that the incorporation of the 
above service bulletins constitutes an optional terminating action for 
the repetitive inspections of paragraph (g) of the original NPRM. ANA 
also requests clarification that the new pumps are not subject to the 
repetitive inspections. Several commenters also point out that Note 3 
of the original NPRM specifies that there is no terminating action 
available for the actions in paragraph (g) and request that Note 3 be 
deleted because there is an optional terminating action.
    We agree with the commenters that the replacements specified in 
Boeing Alert Service Bulletins 767-28A0088 and 767-28A0089 are 
terminating action for the repetitive measurements specified in 
paragraphs (f) and (g) of this supplemental NPRM. However, we do not 
agree that the replacement should be optional. Paragraph (i) of this 
supplemental NPRM would require replacing the fuel pumps and is a 
terminating action for the repetitive measurements specified in 
paragraphs (f) and (g) of this supplemental NPRM. We have also removed 
Note 3 from this supplemental NPRM because there is now terminating 
action.

Request To Exclude Part From Requirements of Paragraph (h)

    ABX Air requests that pump assembly part number (P/N) 5006003D be 
excluded from the requirements of paragraph (h) of the original NPRM. 
The commenter indicates that P/N 5006003D is approved to be installed 
on Model 767 airplanes per Boeing Alert Service Bulletins 767-28A0088 
and 767-28A0089.
    We agree. We have revised paragraph (k) of this supplemental NPRM 
(specified as paragraph (h) in the original NPRM) to allow the 
installation of the main fuel tank boost pump P/N 5006003D.

Request To Revise Compliance Times To Match Service Bulletins

    ANA requests that the compliance times for the original NPRM follow 
the compliance times specified in Boeing Alert Service Bulletins 767-
28A0077 and 767-28A0081. The commenter notes that the original NPRM 
specifies that ``prior to the accumulation of 15,000 total flight 
hours, or within 365 days after the effective date of this AD, 
whichever is later; do a detailed inspection * * *.'' The commenter 
contends that this is different from the alert service bulletins. The 
commenter notes that it is performing the inspections in accordance 
with the alert service bulletins.
    We agree with the commenter's request to follow the compliance 
times in the alert service bulletins. For certain airplanes specified 
in the alert service bulletins, the initial inspections should be done 
within 365 days after the airplane has accumulated 15,000 total flight 
hours. We recognize that the compliance times in the original NPRM 
penalize the operators with airplanes that have accumulated fewer 
flight hours, and that the start of the repetitive inspections should 
be based on the number of hours the airplane has accumulated. 
Therefore, we have revised the compliance times in this supplemental 
NPRM to align with the compliance times specified in the alert service 
bulletins.

Request To Extend Initial Compliance Times to Within 24 Months

    The Air Transport Association requests that the compliance time for 
the initial inspections be extended to 24 months. The commenter 
indicates that a compliance time of 24 months would better align with 
the scheduled maintenance of operators of Model 767 airplanes and would 
align with other fuel tank system actions that may be required as a 
result of Special Federal Aviation Regulation No. 88 (``SFAR 88,'' 
Amendment 21-78, and subsequent Amendments 21-82 and 21-83). The 
commenter also contends that dry running pumps in the main tanks does 
not present a meaningful risk during ground or flight operations 
because those concerns would be eclipsed by fuel starvation of the 
engine. The commenter also states that although there is the risk of 
dry running pumps during defueling operations, it looks to proper 
maintenance procedures for mitigation. The commenter concludes that 
allowing 24 months to do the initial inspection would not impair the 
intended level of safety.
    We do not agree with the commenter to allow the initial inspections 
within 24 months after the effective date of the AD. A study made by 
Hamilton Sundstrand, the manufacturer of the affected fuel pumps, shows 
that up to 25% of the pumps could have loose or missing flame 
arrestors. For this reason, it is necessary to divide the airplanes 
into two groups. For airplanes having line numbers (L/Ns) 1 through 
914, an investigation has indicated that the subject fuel pumps might 
not have flame arrestors. These airplanes would need to be inspected 
for missing flame arrestors within 365 days as specified in Boeing 
Alert Service Bulletins 767-28A0077 and 767-28A0081. For airplanes 
having L/Ns 915 and subsequent: The inspection would need to done 
within 365 days on airplanes that have accumulated more than 15,000 
total flight hours; and on airplanes that accumulated less than 15,000 
total flight hours, the inspection would need to be done within 365 
days after the airplane accumulates 15,000 total flight hours. As there 
are many Model 767 airplanes in the world fleet that have accumulated 
more than 15,000 flight hours, we find that the compliance time of 365 
days would provide an adequate level of safety.
    We also do not agree that dry running pumps in the main tank does 
not present a meaningful risk during ground or flight operations. We 
are concerned that dry running pumps without flame arrestors are 
hazardous due to the lack of data on the ability of the flame front to 
propagate to the ullage through some depth of fuel prior to fuel 
starvation of the engine. Additionally, airplane attitude variation 
during flight operations can uncover at least one of the fuel pump 
inlets prior to fuel starvation, especially during a low fuel

[[Page 38307]]

go around on approach. Proper maintenance procedures mitigate the risk 
during defueling operations; however, defueling can occur with 
passengers on board and we have concerns with improperly conducted 
maintenance procedures.
    The basis for the compliance times specified by this supplemental 
NPRM includes the fact that a missing flame arrestor does not present a 
very high risk for most flight conditions when there is enough fuel to 
cover the pump inlet as the probability of a flame reaching the fuel 
tank is significantly reduced if fuel covers the pump inlet.
    In developing appropriate compliance times for this supplemental 
NPRM, we considered the manufacturer's recommendation specified in the 
alert service bulletins, the degree of urgency associated with the 
subject unsafe condition, the average utilization of the affected fleet 
and the time necessary to perform the actions. In light of all of these 
factors, we find that the compliance times specified in this 
supplemental NPRM represent an appropriate interval of time for 
affected airplanes to continue to operate without compromising safety. 
However, an operator may request an alternative method of compliance 
(AMOC) to extend the compliance time in accordance with paragraph (l) 
of this supplemental NPRM.

Request To Revise Applicability and Compliance Times

    Boeing recommends that the compliance times for airplanes having L/
Ns 915 through 926 be revised to match the compliance times specified 
in the alert service bulletins for airplanes having L/Ns 1 through 914. 
The commenter notes that the applicability of L/Ns 1 through 914 for 
the one set of compliance times was based on Hamilton Sundstrand 
determining which pumps had the missing flame arrestors. However, the 
commenter states that the terminating action design was incorporated at 
L/N 927 with the new main boost pump part number specified in Boeing 
Alert Service Bulletins 767-28A0088 and 767-28A0089. Therefore, the 
commenter notes that including airplanes having L/Ns 915 through 926 in 
the compliance times for L/Ns 1 through 914 would clarify when the new 
pump number was installed. The commenter recommends the following 
compliance times for the original NPRM:

    ``For aircraft having L/N 1-926, do an initial inspection within 
365 days. For those aircraft with more than 15,000 hours, do the 
inspection again at each 6,000 flight interval or 24 months 
whichever comes first. For those aircraft with less than 15,000 
hours, do the inspection again within 365 days from the date the 
aircraft reaches 15,000 hours. Repeat the inspection at each 6,000 
flight interval or 24 months whichever comes first.''

    Since Boeing's comments were not consistent with its own service 
bulletin recommendation, we contacted the manufacturer for 
clarification on its position. Boeing revised its position to be 
consistent with Boeing Alert Service Bulletins 767-28A0077 and 767-
28A0081 for airplanes having L/Ns 1 through 926 and further recommended 
that for airplanes having L/N 927 and on, an inspection is not required 
since the airplane already has the new part number installed.
    While we acknowledge that airplanes having L/N 927 and subsequent 
have been equipped with the new pumps in production, the pumps may have 
been replaced since then. Therefore, all airplanes must be inspected. 
However, operators may examine their records to determine if the new 
fuel pumps are installed. If it is conclusively determined that the new 
pumps are installed, no further action is necessary. We have added new 
paragraph (h) to allow a records review to determine if the new pump is 
installed.

Request To Reference Future Revision of Service Bulletin

    ATA, on behalf of its members, American Airlines and United 
Airlines, requests that the original NPRM reference Revision 2 of the 
Boeing Alert Service Bulletins 767-28A0077 and 767-28A0081. The 
commenter states that Revision 2 will cite Hamilton-Sundstrand Service 
Bulletin 5006003-28-3, which would provide the instructions to 
incorporate into the subject fuel pumps a new shaft and rotor assembly 
designed to correct the problem.
    We do not agree. We have confirmed with Boeing that Alert Service 
Bulletins 767-28A0077 and 767-28A0081 will not be revised to provide a 
terminating action. As discussed previously, Boeing has issued Alert 
Service Bulletins 767-28A0088 and 767-28A0089, which constitute 
terminating actions for the repetitive actions of paragraphs (f) and 
(g) of this supplemental NPRM.

Request To Revise Cost

    ATA, on behalf of its member United Airlines, requests that the 
cost analysis be revised. ATA requests that the cost analysis include 
items such as the impact of airplanes rerouting to a maintenance 
facility, aircraft preparation, access, correction of discrepancies 
found, aircraft close-up, and any additional test necessary to put the 
airplane back in operation. United Airlines states that the repair cost 
of pumps should be included because Hamilton-Sundstrand quoted a 25% 
failure rate. United Airlines also notes that 60% of the pumps it has 
inspected had inlet diffuser struts eroded beyond the specified limits 
and therefore, pump repairs and replacement sleeve costs should be 
included.
    We do not agree to revise the cost analysis. In establishing the 
requirements of all ADs, we do consider cost impact to operators beyond 
the estimates of parts and labor costs contained in AD preambles. For 
example, where safety considerations allow, we attempt to set 
compliance times that generally coincide with operators' maintenance 
schedules. However, because operators' schedules vary substantially, we 
cannot accommodate every operator's optimal scheduling in each AD. Each 
AD does allow individual operators to obtain approval for extensions of 
compliance times, based on a showing that the extension will not affect 
safety adversely. Therefore, we do not consider it appropriate to 
attribute to this supplemental NPRM the costs associated with the type 
of special scheduling that might otherwise be required.
    Furthermore, we do not consider it appropriate to attribute the 
costs associated with aircraft ``down time'' to this supplemental NPRM. 
Normally, compliance with an AD will not necessitate any additional 
down time beyond that of a regularly scheduled maintenance hold. Even 
if additional down time is necessary for some airplanes in some cases, 
we do not have sufficient information to evaluate the number of 
airplanes that may be so affected or the amount of additional down time 
that may be required as this may vary from operator to operator. 
Therefore, attempting to estimate such costs is not appropriate.
    In addition, the economic analysis does not consider the costs of 
conditional actions, such as repairing a crack detected during a 
required inspection (``repair, if necessary''). Such conditional 
repairs would be required, regardless of AD direction, to correct an 
unsafe condition identified in an airplane and to ensure that the 
airplane is operated in an airworthy condition, as required by the 
Federal Aviation Regulations.
    The compliance times presented in this supplemental NPRM were 
developed to minimize the economic impact on operators as much as 
possible while being consistent with the safety

[[Page 38308]]

objectives associated with this supplemental NPRM and the referenced 
alert service bulletins. We have not revised this supplemental NPRM in 
this regard.

Request for SFAR 88 Information

    ATA questions if the original NPRM originated from the SFAR 88 fuel 
tank system safety review.
    We confirm that this supplemental NPRM did not originate from the 
SFAR 88 fuel tank system safety review.

Request To Remove Repetitive Inspections

    Delta Airlines states that it is not convinced the repetitive 
inspections specified in the original NPRM are necessary. We infer that 
the commenter requests that the repetitive inspections be removed. The 
commenter states that the risk of problems associated with missing or 
loose boost pump flame arrestors is not great enough to justify 
repetitive inspections fleetwide. The commenter also states that the 
pump flame arrestors have been found loose but not missing, and that 
they retain their flame arresting qualities if loose. In addition, the 
commenter states that if a sheared roll pin is going to cause a 
problem, it is going to occur immediately after the pin fails; since 
the roll pin can shear at any time, no amount of inspections would 
prevent pin failures.
    The commenter believes that the more likely scenario, dry running 
pumps in the main tanks during ground or flight operations, is not a 
meaningful risk because those concerns would be eclipsed by fuel 
starvation of the engines. The commenter notes that it looks to proper 
maintenance procedures for mitigation of the risk of dry running pumps 
during defueling operations. The commenter suggests that installation 
of an improved pin or a pin replacement program would solve the problem 
better than repetitive inspections.
    We understand Delta's concerns; however, we do not agree to remove 
the repetitive inspections. The objective of the flame arrestor is to 
preclude a flame originated in the reprime unit or beyond from moving 
to the fuel tank. The flame arrestor may drop into the reprime unit 
area if the flame arrestor pin is broken and contacts rotating parts; 
in this position, a flame arrestor might create sparks that ignite the 
fuel vapors. A misplaced or missing flame arrestor represents a latent 
failure that leaves the airplane one failure away from a fuel tank 
ignition.
    The probability of a flame reaching the fuel tank is significantly 
reduced if fuel covers the pump inlet. The compliance times specified 
by this supplemental NPRM recognize the fact that a missing flame 
arrestor does not present a very high risk for most flight conditions 
when there is enough fuel to cover the pump inlet. We find that, to 
achieve an adequate level of safety for the affected fleet, repetitive 
inspections are necessary. We have not revised this supplemental NPRM 
in this regard.

Request To Reference Part Numbers

    The Modification and Replacement Parts Association (MARPA) requests 
that we identify the affected fuel pumps in the original NPRM by either 
Boeing or Hamilton Sundstrand (or both) part numbers. The MARPA also 
requests that we include any possible defective parts manufacturer 
approval (PMA) alternative parts so that any defective PMA parts are 
also subject to the original NPRM.
    The commenter asserts that, under 14 CFR 21.303, there may be fuel 
pumps that could be approved replacement parts for the affected fuel 
pumps. If replacement parts do exist, the MARPA states that the PMA 
fuel pumps may have a different part number from the affected fuel 
pumps and therefore will not likely be addressed by model or serial 
number in the service information. Therefore, the MARPA asserts that a 
regulatory loophole is created if a ``defective'' PMA part is 
installed, because only the original equipment manufacturer (OEM) part 
will be identified in the manufacturer service information. In 
addition, the MARPA states that the affected fuel pumps are identified 
in proprietary service information that is not available to the general 
public and that the proprietary service information may also not be 
available to supplier or repair facilities. Therefore, the MARPA 
concludes that repair and supply facilities might have defective OEM or 
PMA parts in stock that could be put into service unless such parts are 
identified as subject to the requirements of the original NPRM.
    We acknowledge the MARPA's concerns; however, we do not agree that 
it is necessary to identify the manufacturer and part numbers of the 
subject fuel pumps. At this time, we are not aware of other PMA parts 
equivalent to the affected fuel pumps. Also, this supplemental NPRM 
would require that all fuel pumps be inspected, regardless of origin. 
Since the part numbers of the affected fuel pumps are identified in the 
applicable Boeing and Hamilton Sundstrand service bulletins specified 
in the supplemental NPRM, it is unnecessary to specify part numbers in 
the supplemental NPRM.
    We concur with the MARPA's general request that, if we know that an 
unsafe condition also exists in PMA parts, the AD should address those 
parts, as well as the original parts. The MARPA's remarks are timely in 
that the Transport Airplane Directorate currently is in the process of 
reviewing this issue as it applies to transport category airplanes. We 
acknowledge that there may be other ways of addressing this issue to 
ensure that unsafe PMA parts are identified and addressed. Once we have 
thoroughly examined all aspects of this issue, including input from 
industry, and have made a final determination, we will consider whether 
our policy regarding addressing PMA parts in ADs needs to be revised.
    In response to the commenter's statement regarding a ``regulatory 
loophole,'' this statement appears to reflect a misunderstanding of the 
relationship between ADs and the certification procedural regulations 
of part 21 of the Federal Aviation Regulations (14 CFR part 21). Those 
regulations, including section 21.303 of the Federal Aviation 
Regulations (14 CFR 21.203), are intended to ensure that aeronautical 
products comply with the applicable airworthiness standards. But ADs 
are issued when, notwithstanding those procedures, we become aware of 
unsafe conditions in these products or parts. Therefore, an AD takes 
precedence over design approvals when we identify an unsafe condition.
    Since we have determined that an unsafe condition exists and that 
replacement of certain parts must be accomplished to ensure continued 
safety, no additional change has been made to the supplemental NPRM in 
this regard.

Request To Reference PMA Parts

    The MARPA requests that the language in the original NPRM be 
changed to embrace any PMA alternatives.
    We infer that the MARPA would like the original NPRM to permit 
installation of any equivalent PMA parts so that it is not necessary 
for an operator to request approval of an AMOC in order to install an 
``equivalent'' PMA part. Whether an alternative part is ``equivalent'' 
in adequately resolving the unsafe condition can only be determined on 
a case-by-case basis based on a complete understanding of the unsafe 
condition. We are not currently aware of any such parts. Our policy is 
that, in order for operators to replace a part with one that is not 
specified in an AD, they must request an AMOC. This is necessary so 
that we can make a specific determination that an

[[Page 38309]]

alternative part is or is not susceptible to the same unsafe condition.
    An AD provides a means of compliance for operators to ensure that 
the identified unsafe condition is addressed appropriately. For an 
unsafe condition attributable to a part, an AD normally identifies the 
replacement parts necessary to obtain that compliance. As stated in 
section 39.7 of the Federal Aviation Regulations (14 CFR 39.7), 
``Anyone who operates a product that does not meet the requirements of 
an applicable airworthiness directive is in violation of this 
section.'' Unless an operator obtains approval for an AMOC, replacing a 
part with one not specified by an AD would make the operator subject to 
an enforcement action and result in a civil penalty. No change to this 
supplemental NPRM is necessary in this regard.

Request To Allow Doing Actions on the Main Fuel Tanks Separately

    ANA requests that we permit operators to do the inspection of each 
main fuel tank separately and not require operators to do an inspection 
of all main fuel tanks on an airplane at the same maintenance stop. 
Also, the commenter requests that we permit operators to do any 
terminating action for each main fuel tank independent of the other. 
The commenter states that this will provide flexibility to operators. 
The commenter notes that it does not have many spare pumps.
    We acknowledge that doing the actions in the supplemental NPRM at a 
separate time for each main fuel tank would provide flexibility to the 
operators. Operators may do the actions for each pump separately 
provided that operators have done the actions on all pumps within the 
applicable compliance times specified in the supplemental NPRM. We have 
added Note 1, Note 4, and Note 5 to this supplemental NPRM to clarify 
that the actions may be done separately provided that all actions are 
done within the applicable compliance times.

FAA's Determination and Proposed Requirements of the Supplemental NPRM

    Certain changes discussed above expand the scope of the original 
NPRM; therefore, we have determined that it is necessary to reopen the 
comment period to provide additional opportunity for public comment on 
this supplemental NPRM.

Explanation of Change to Applicability

    We have revised the applicability of the original NPRM to identify 
model designations as published in the most recent type certificate 
data sheet for the affected models.

Clarification of Unsafe Condition Statement

    The original NPRM specified the unsafe condition as ``the possible 
migration of a flame from a main tank fuel boost pump inlet to the 
vapor space of that fuel tank, and consequent ignition of fuel vapors, 
which could result in a fire or explosion, should the pump inlets 
become uncovered.'' We have revised the unsafe condition statement in 
this supplemental NPRM by removing the phrase ``should the pump inlets 
become uncovered.'' The pump inlet does not need to be uncovered for 
ignited vapors in the pump to cause a tank explosion.

Clarification of AMOC Paragraph

    We have revised this action to clarify the appropriate procedure 
for notifying the principal inspector before using any approved AMOC on 
any airplane to which the AMOC applies.

Costs of Compliance

    This supplemental NPRM affects about 915 airplanes worldwide, and 
400 airplanes of U.S. registry. The following table provides the 
estimated costs for U.S. operators to comply with this supplemental 
NPRM.

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                            Average
                                    Work     labor
             Action                hours    rate per        Parts        Cost per airplane        Fleet cost
                                              hour
----------------------------------------------------------------------------------------------------------------
Inspection of flame arrestor            5        $80  None............  $400, per            $160,000, per
 presence/Position.                                                      inspection cycle.    inspection cycle.
Replacement.....................        3         80  $25,004.........  $25,244............  $10,097,600. \1\
----------------------------------------------------------------------------------------------------------------
\1\ However, the parts manufacturer states that it may cover the cost of replacement parts associated with this
  supplemental NPRM for certain affected airplanes, subject to warranty conditions. As a result, the costs
  attributable to the supplemental NPRM may be less than stated above.

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 supplemental NPRM and placed it in the AD docket. 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.

[[Page 38310]]

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 Federal Aviation Administration (FAA) amends Sec.  39.13 by 
adding the following new airworthiness directive (AD):

Boeing: Docket No. FAA-2005-20351; Directorate Identifier 2003-NM-
269-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by July 31, 
2006.

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 reports that certain fuel boost pumps 
may not have flame arrestors installed in the pump shaft and reports 
that the pin that holds the flame arrestor in place can break due to 
metal fatigue. We are issuing this AD to prevent the possible 
migration of a flame from a main tank fuel boost pump inlet to the 
vapor space of that fuel tank, and consequent ignition of fuel 
vapors, which could result in a fire or explosion.

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.

Inspection for Presence/Position of Flame Arrestor in Main Tank Fuel 
Boost Pumps

    (f) For airplanes having line numbers (L/Ns) 1 through 914 
inclusive, except as provided by paragraph (h) of this AD: Within 
365 days after the effective date of this AD, do a detailed 
inspection of each main tank fuel boost pump to determine if the 
pump shaft flame arrestor is installed, a measurement of the flame 
arrestor's position in the pump, and all applicable corrective 
actions, by accomplishing all the actions specified in the 
Accomplishment Instructions of Boeing Alert Service Bulletin 767-
28A0077 (for Model 767-200, -300, and -300F series airplanes) or 
Boeing Alert Service Bulletin 767-28A0081 (for Model 767-400ER 
series airplanes), both Revision 1, both dated July 8, 2004, as 
applicable. Repeat the measurement of the flame arrestor's position 
in the pump thereafter at intervals not to exceed the applicable 
time specified in paragraph (f)(1) or (f)(2) of this AD, until the 
replacement required by paragraph (i) of this AD is accomplished. 
All applicable corrective actions must be done before further 
flight.

    Note 1: Any inspection/measurement of the pumps on the left and 
right main fuel tanks may be done separately provided that the 
actions are done on all pumps within the compliance time specified 
in paragraph (f) of this AD.

    (1) For airplanes that have accumulated more than 15,000 total 
flight hours as of the date the initial actions are done in 
accordance with paragraph (f) of this AD: Repeat the measurement 
thereafter at intervals not to exceed 6,000 flight hours or 24 
months, whichever comes first.
    (2) For airplanes that have accumulated 15,000 total flight 
hours or fewer as of the date the initial actions are done in 
accordance with paragraph (f) of this AD: Do the measurement 
specified in paragraph (f) of this AD within 365 days after the date 
on which the airplane accumulates 15,000 total flight hours. Repeat 
the measurement thereafter at intervals not to exceed 6,000 flight 
hours or 24 months, whichever comes first.

    Note 2: The Boeing alert service bulletins reference Hamilton 
Sundstrand Service Bulletin 5006003-28-2, dated October 25, 2002, as 
an additional source of service information for accomplishment of 
the inspection and corrective actions. Although the Hamilton 
Sundstrand service bulletin specifies to return main tank fuel boost 
pumps with damaged, broken, or out-of-position flame arrestors to a 
repair shop, that action is not required by this AD.


    Note 3: For the purposes of this AD, a detailed inspection is: 
``An intensive examination of a specific item, installation, or 
assembly to detect damage, failure, or irregularity. Available 
lighting is normally supplemented with a direct source of good 
lighting at an intensity deemed appropriate. Inspection aids such as 
mirror, magnifying lenses, etc., may be necessary. Surface cleaning 
and elaborate procedures may be required.''

    (g) For airplanes having L/Ns 915 and on, except as provided by 
paragraph (h) of this AD: At the applicable time specified in 
paragraph (g)(1) or (g)(2) of this AD, do a detailed inspection of 
each main tank fuel boost pump to determine if the pump shaft flame 
arrestor is installed, a measurement of the flame arrestor's 
position in the pump, and all applicable corrective actions, by 
accomplishing all the actions specified in the Accomplishment 
Instructions of Boeing Alert Service Bulletin 767-28A0077 (for Model 
767-200, -300, and -300F series airplanes) or Boeing Alert Service 
Bulletin 767-28A0081 (for Model 767-400ER series airplanes), both 
Revision 1, both dated July 8, 2004, as applicable. Repeat the 
measurement of the flame arrestor's position in the pump thereafter 
at intervals not to exceed 6,000 flight hours or 24 months, 
whichever comes first, until the replacement required by paragraph 
(i) of this AD is accomplished. All applicable corrective actions 
must be done before further flight.

    Note 4: Any inspection/measurement of the pumps on the left and 
right main fuel tanks may be done separately provided that the 
actions are done on all pumps within the compliance time specified 
in paragraph (g) of this AD.

    (1) For airplanes that have accumulated more than 15,000 total 
flight hours as of the effective date of this AD, do the actions 
within 365 days after the effective date of this AD.
    (2) For airplanes that have accumulated 15,000 total flight 
hours or fewer as of the effective date of this AD, do the actions 
within 365 days after the date on which the airplane accumulates 
15,000 total flight hours.

Optional Terminating Action--Records Review

    (h) For any period when the part number (P/N) of a main tank 
fuel boost pump installed on any airplane, as conclusively 
determined from a review of airplane maintenance records, is P/N 
5006003D, no further action is required by paragraphs (f), (g), and 
(i) of this AD for that pump only.

Replacement of the Main Tank Fuel Boost Pumps

    (i) Within 36 months after the effective date of this AD, 
replace the left and right main tank fuel boost pumps with new or 
modified pumps in accordance with the Accomplishment Instructions of 
Boeing Alert Service Bulletin 767-28A0088 (for Model 767-200, -300, 
and -300F series airplanes) or Boeing Alert Service Bulletin 767-
28A0089 (for Model 767-400ER series airplanes), both dated February 
24, 2005, as applicable. Accomplishment of the replacement 
terminates the repetitive measurement requirements of paragraphs (f) 
and (g) of this AD for that pump only.

    Note 5: Any replacement of the pumps on the left and right main 
fuel tanks may be done separately provided that all pumps are 
replaced within the compliance time specified in paragraph (i) of 
this AD.


    Note 6: The Boeing alert service bulletins reference Hamilton 
Sundstrand Service Bulletin 5006003-28-3, dated December 8, 2004, as 
the appropriate source of service information for modifying the 
pump.

Inspections Accomplished According to Previous Issue of Service 
Bulletin

    (j) Inspections accomplished before the effective date of this 
AD according to Boeing Alert Service Bulletin 767-28A0077, dated 
March 6, 2003; or Boeing Alert Service Bulletin 767-28A0081, dated 
March 6, 2003; are considered acceptable for compliance with the 
corresponding action specified in paragraphs (f) and (g) of this AD.

Parts Installation

    (k) As of the effective date of this AD, only main tank fuel 
boost pumps identified in paragraphs (k)(1) and (k)(2) of this AD 
may be installed on any airplane.
    (1) Any main tank fuel boost pump that has been inspected, and 
on which all applicable corrective actions have been performed, in 
accordance with paragraph (f) or (g) of this AD.

[[Page 38311]]

    (2) Any main tank fuel boost pump having P/N 5006003D.

Alternative Methods of Compliance (AMOCs)

    (l)(1) The Manager, Seattle Aircraft Certification Office, FAA, 
has the authority to approve AMOCs for this AD, if requested in 
accordance with the procedures found in 14 CFR 39.19.
    (2) Before using any AMOC approved in accordance with Sec.  
39.19 on any airplane to which the AMOC applies, notify the 
appropriate principal inspector in the FAA Flight Standards 
Certificate Holding District Office.

    Issued in Renton, Washington, on June 13, 2006.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E6-10536 Filed 7-5-06; 8:45 am]
BILLING CODE 4910-13-P