E6-10536. 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.

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 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: [phone].
• 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 [phone]; fax [phone].

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 [phone]) 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 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 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 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 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

Action	Work hours	Average labor rate per hour	Parts	Cost per airplane	Fleet cost
Inspection of flame arrestor presence/Position	5	$80	None	$400, per inspection cycle	$160,000, per 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

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.

§ 39.13

[Amended]

2. The Federal Aviation Administration (FAA) amends § 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.

(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 § 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.