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Proposed Rule

Airworthiness Directives; Boeing Model 737-300, -400, -500, -600, -700, -700C, -800, and -900, and 747-400 Series Airplanes; and Model 757, 767, and 777 Airplanes

Document Details

Information about this document as published in the Federal Register.

Published Document

This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.

Start Preamble

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Supplemental notice of proposed rulemaking; reopening of comment period.

SUMMARY:

This document revises an earlier supplemental notice of proposed Start Printed Page 1160rulemaking (NPRM), applicable to certain Boeing Model 737-300, -400, -500, -600, -700, -700C, -800, and -900, and 747-400 series airplanes; and Model 757, 767, and 777 airplanes. The first supplemental NPRM would have required modifying the static inverter by replacing resistor R170 with a new resistor and relocating the new resistor. This new action revises the first supplemental NPRM by adding certain airplanes to the applicability, changing certain airplane groups, and adding certain part numbers. The actions specified by this second supplemental NPRM are intended to prevent a standby static inverter from overheating, which could result in smoke in the flight deck and cabin and loss of the electrical standby power system. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by February 6, 2009.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2002-NM-12-AD, 1601 Lind Avenue, SW., Renton, Washington 98057-3356. Comments may be inspected at this location between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays. Comments may be submitted via fax to (425) 227-1232. Comments may also be sent via the Internet using the following address: 9-anm-nprmcomment@faa.gov. Comments sent via fax or the Internet must contain “Docket No. 2002-NM-12-AD” in the subject line and need not be submitted in triplicate. Comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 or 2000 or ASCII text.

The service information referenced in the proposed rule may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.

Start Further Info

FOR FURTHER INFORMATION CONTACT:

Binh V. Tran, Aerospace Engineer, Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 917-6485; fax (425) 917-6590.

End Further Info End Preamble Start Supplemental Information

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this action may be changed in light of the comments received.

Submit comments using the following format:

  • Organize comments issue-by-issue. For example, discuss a request to change the compliance time and a request to change the service bulletin reference as two separate issues.
  • For each issue, state what specific change to the proposed AD is being requested.
  • Include justification (e.g., reasons or data) for each request.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this action must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2002-NM-12-AD.” The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2002-NM-12-AD, 1601 Lind Avenue, SW., Renton, Washington 98057-3356.

Discussion

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to add an airworthiness directive (AD), applicable to certain Boeing Model 737-300, -400, -500, -600, -700, -700C, -800, and -900, and 747-400 series airplanes; and Model 757, 767, and 777 airplanes, was published as a supplemental notice of proposed rulemaking (NPRM) in the Federal Register on May 26, 2006 (71 FR 30331). The first supplemental NPRM would have required modifying the static inverter by replacing resistor R170 with a new resistor and relocating the new resistor. The first supplemental NPRM was prompted by further evaluation of the carbon resistor, which revealed a failure mode that can cause the resistor to ignite, involving adjacent capacitors as well. Those conditions, if not corrected, could result in smoke in the flight deck and cabin and loss of the electrical standby power system.

Actions Since Issuance of First Supplemental NPRM

Since issuance of the first supplemental NPRM, Boeing has revised the service bulletins listed in the following table:

Revised Service Bulletins

ActionService bulletinModel
ModificationBoeing Alert Service Bulletin 737-24A1166, Revision 2, dated January 29, 2007737-300, -400, -500 series airplanes.
ModificationBoeing Alert Service Bulletin 737-24A1166, Revision 3, dated July 25, 2007737-300, -400, -500 series airplanes.
ModificationBoeing Service Bulletin 747-24-2254, Revision 1, dated March 5, 2007747-400, -400D, -400F series airplanes.
ModificationBoeing Service Bulletin 777-24-0095, Revision 1, dated January 3, 2007777-200, -300, -300ER series airplanes.

The changes in these revisions are minor and no additional work is necessary for certain airplanes modified by the previous issues. However, more work is necessary on airplanes with certain static inverters installed. In addition, the revisions all add airplanes to those specified in the effectivity or move airplanes to different groups. Alert Start Printed Page 1161Service Bulletin 737-24A1166, Revision 2, also adds two missing supplier part numbers, which are related to the existing Boeing part numbers, for the static inverters. Airplanes that were modified by installing the correct static inverter having the correct part number, as specified in Service Bulletin 737-24A1166, Revision 1, dated October 20, 2005, or 747-24-2254, dated July 21, 2005, are not affected by the modification in the revised service information. Airplanes that were modified as specified in Service Bulletin 777-24-0095, dated June 30, 2005, are not affected by the modification specified in Revision 1 of that bulletin. We have changed the second supplemental NPRM to refer to this revised service information as the appropriate source of service information for accomplishing the specified modification.

The revised service bulletins refer to Avionic Instruments Inc. Service Bulletin 1-002-0102-1000-24-28, Revision B, dated July 24, 2006, as an additional source of service information for modifying the static inverter.

Comments on First Supplemental NPRM

Due consideration has been given to the comments received in response to the first supplemental NPRM.

Support for the First Supplemental NPRM

The National Transportation Safety Board, Northwest Airlines, and Alaska Airlines support the intent of the first supplemental NPRM.

Request To Approve Revised Avionic Instruments Inc. (AII) Service Bulletin

United Airlines (UA) asks that we approve the latest AII Service Bulletin 1-002-0102-1000-24-28; Revision A, dated June 22, 2005, was referenced in the first supplemental NPRM as an additional source of service information for doing the modification. UA adds that certain references to service information related to this AD on the Boeing Web site do not have cross references to the AII service bulletin. UA suggests that, to avoid confusion, Revision A remain as an additional source of service information for the rework.

We agree to leave Revision A of the referenced service bulletin in the note in the second supplemental NPRM. We have reviewed AII Service Bulletin 1-002-0102-1000-24-28, Revision B, dated July 24, 2006 (hereafter referred to as the AII service bulletin). We find that both Revision A and Revision B of the AII service bulletin are still acceptable as additional sources of service information for modifying the static inverter. We have changed Note 1 of the second supplemental NPRM to include Revision B of the service bulletin; Revision A remains in Note 1.

Request for Work Instructions To Apply To Both Airplane Groups

UA suggests that the group separation specified in the Work Instructions in Boeing Service Bulletin 757-24-0110, dated April 28, 2005, be disregarded, and the Group 1 Work Instructions apply to all airplanes. That service bulletin was referred to in the first supplemental NPRM as the appropriate source of service information for accomplishing the modification for Model 757-200, -200CB, -200PF airplanes. UA states that the Work Instructions are divided into Group 1 and Group 2, based on the inverter part number as delivered configuration. UA adds that the current Boeing Illustrated Parts Catalog shows inverter part numbers are applicable to the entire 757 fleet, which conflicts with the purpose of the service bulletin in separating the Work Instructions into two airplane groups.

We acknowledge UA's request; however, Boeing has informed us that Service Bulletin 757-24-0110 will not be revised to incorporate the requested changes. Under the provisions of paragraph (b) of the second supplemental NPRM, however, we could consider requests for combining the Work Instructions if data are submitted to substantiate that using the Group 1 Work Instructions for all airplanes would provide an acceptable level of safety. We have made no change to the second supplemental NPRM in this regard.

Request To Include Certain Part Numbers

UA states that the FAA response to the comment “Request for Clarification of Part Number” specified in the first supplemental NPRM indicates that supplier part number 1-001-0102-0265 is not an inverter part number; UA disagrees with the response. UA adds that Boeing Illustrated Parts Catalog, for Model 737-300/400/500 and Model 747-400, indicates that Specification Number S282T004-5 corresponds to both part numbers 1-001-0102-0265 and 1-002-0102-0265. UA asks that, in order to avoid confusion, the second supplemental NPRM clarify the existence and applicability of both part numbers.

We agree with the request. Revision B of AII Service Bulletin 1-002-0102-1000-24-28, dated July 24, 2006, includes the subject part numbers, and we have included Revision B in the second supplemental NPRM as an additional source of service information for modifying the static inverter.

Request To Include Future Revisions of Service Information

Boeing asks that we address imminent revisions of the service bulletins identified in the first supplemental NPRM, as well as possible future revisions to any of the identified bulletins. Boeing states that revisions to the 747 and 777 service bulletins, which will add several airplanes to the effectivity lists in the bulletins, are imminent. Boeing notes that, as written, the applicability paragraph in the first supplemental NPRM will not include the added airplanes. Boeing suggests the applicability paragraph be changed to read “* * * the applicable service bulletin specified in Table 1 of this AD or subsequent revision(s) to that bulletin.”

We understand the commenter's concern, and we have included the revised service information specified under “Actions Since Issuance of First Supplemental NPRM,” which adds airplanes to the applicability section of this AD. However, we cannot use the phrase, “or later FAA-approved revisions” in an AD because doing so violates Office of the Federal Register (OFR) regulations for approval of materials “incorporated by reference” in rules. In general terms, we are required by these OFR regulations either to publish the service document contents as part of the actual AD language; or to submit the service document to the OFR for approval as “referenced” material, in which case we may refer to such material in the text of an AD. The AD may refer to the service document only if the OFR approved it for “incorporation by reference.” To allow operators to use later revisions of the referenced documents (issued after publication of the AD), Boeing or operators must request approval to use later revisions as an alternative method of compliance with the AD under the provisions of paragraph (b) of the AD.

Request To Remove Model 747 and 777 Airplanes From the Applicability

Air Transport Association (ATA), on behalf of its member American Airlines (AA), and Boeing, asks that we remove Model 747 and 777 airplanes from the applicability of the first supplemental NPRM. ATA and AA state that we should delete Model 777 airplanes from the applicability of the first supplemental NPRM because the inverters on those airplanes have a different configuration and are not Start Printed Page 1162susceptible to the subject unsafe condition. Boeing Safety Review Board made a finding of “Not Safety” for the Model 747 and 777 airplanes. Boeing adds that there have been no failures on these models, and the inverters on these models are not running during normal operations.

We do not agree with the requests. Model 747 and 777 airplanes have the same type of static inverters that were installed on the airplanes specified in the first supplemental NPRM. Those static inverters could overheat at anytime during operation due to a faulty resistor. As stated in Boeing Service Bulletins 747-24-2254 and 777-24-0095, the static inverter change will prevent the possible unwanted smoke and fire from a faulty resistor in the static inverter. Therefore, Model 747 and 777 airplanes will remain in the applicability of the second supplemental NPRM. We acknowledge that the static inverters are not running during normal operations, but they could overheat during emergency operations (standby conditions). However, we have determined that due to the reduced risk on Model 747 and 777 airplanes, the compliance time for those airplanes can be extended to 60 months. We have revised paragraph (a) of this AD accordingly.

Requests To Extend Compliance Time

ATA, on behalf of its member American Airlines, asks that we extend the proposed compliance time to 10 years for airplanes on which the AII service bulletin has been incorporated. AA asks that, due to existing maintenance intervals, the compliance time be extended to 60 months for operators that accomplished the first supplemental NPRM. AA adds that its justification stems from the heat being reduced in the area of the capacitors C50 and C51, with the resistor R170 on the solder side of the printed circuit board.

We do not agree with the request. As stated in “Actions Since Issuance of Previous Proposal,” in the first supplemental NPRM, recent in-service experience has shown that simply relocating the carbon composition-style resistor, which was installed in production until late 1999, did not prevent the overheat condition. Further evaluation of the carbon resistor has shown a failure mode that can cause the resistor to ignite. Incorporation of the AII service bulletin will not mitigate the safety concern. In developing an appropriate compliance time for this action, we considered the urgency associated with the subject unsafe condition, the availability of required parts, and the practical aspect of accomplishing the required modification within a period of time that corresponds to the normal scheduled maintenance for most affected operators. According to the manufacturer, an ample number of required parts will be available to modify the U.S. fleet within the proposed compliance time. Therefore, we find that 42 months is sufficient time in which to do the modification. However, according to the provisions of paragraph (b) of the second supplemental NPRM, we could approve requests to adjust the compliance time if the request includes data that prove that the new compliance time would provide an acceptable level of safety.

Request for Component AD

AirTran Airways Inc. (AirTran) reiterates the comments under “Request for a Component AD” specified in the first supplemental NPRM and states that this second supplemental NPRM should be a “component AD” rather than an aircraft AD. AirTran states that once an aircraft delivers from the factory with a component installed, that component is likely to be replaced due to failure and subsequently installed on another aircraft outside of the effectivity range. AirTran notes that it is unrealistic to expect that a component that has qualified interchangeables will still be installed on the aircraft on which it was delivered. AirTran states that the AD should be written in a manner that best ensures the safety of the flying public; this involves considering how operators use the aircraft and not necessarily how the manufacturer built the aircraft. AirTran adds that by making the AD applicable to the part number unit, operators are more likely to identify all affected units and remove them from their system, including spares that are not addressed in the first supplemental NPRM, than if the AD is effective to aircraft line or serial numbers.

We do not agree with the request. We have confirmed with Boeing that the service bulletins cited in the applicability list all the airplanes on which the parts addressed by this AD are eligible for installation. We have also confirmed with Boeing that the Illustrated Parts Catalogs have been properly updated. For these reasons, there is no need to further define the applicability. We have made no change to the second supplemental NPRM in this regard.

Request To Change Cost Impact Section

ATA, on behalf of its member American Airlines, asks that the cost impact section be changed. ATA states that the proposed modification could be accomplished by either a repair facility or the operator. ATA adds that the FAA should amend the cost impact to include both of these alternatives. Both commenters recommend adding 2 hours of labor and the value of materials for the modification of the inverter to the cost section.

We acknowledge the commenters' concerns. We recognize that, in accomplishing the requirements of any AD, operators might incur “incidental” costs in addition to the “direct” costs that are reflected in the cost analysis presented in the AD preamble. However, the cost analysis in AD rulemaking actions typically does not include incidental costs.

Further, because ADs require specific actions to address specific unsafe conditions (i.e., using a repair facility) they appear to impose costs that would not otherwise be borne by operators. However, because of the general obligation of operators to maintain and operate their airplanes in an airworthy condition, this appearance is deceptive. Attributing those costs solely to the issuance of this AD is unrealistic because, in the interest of maintaining and operating safe airplanes, prudent operators would accomplish the required actions even if they were not required to do so by the AD. In any case, we have determined that direct and incidental costs are still outweighed by the safety benefits of the AD. We have made no change to the second supplemental NPRM in this regard.

Clarification of Alternative Methods of Compliance (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.

Conclusion

Since certain changes expand the scope of the first supplemental NPRM, we have determined that it is necessary to reopen the comment period to provide additional opportunity for public comment.

Cost Impact

There are approximately 3,856 airplanes of the affected design in the worldwide fleet. The FAA estimates that 1,882 airplanes of U.S. registry would be affected by the second supplemental NPRM. The following table provides the estimated costs for U.S. operators to comply with the second supplemental NPRM. Start Printed Page 1163

Estimated Costs

ActionWork hoursAverage labor rate per hourPartsCost per airplaneNumber of U.S.-registered airplanesFleet cost
ModificationUp to 2 hours, depending on airplane configuration$80$0Between $80 and $1601,882Up to $301,120.

The cost impact figure discussed above is based on assumptions that no operator has yet accomplished any of the proposed requirements of this AD action, and that no operator would accomplish those actions in the future if the second supplemental NPRM were not adopted. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions.

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 Impact

The regulations proposed herein 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. Therefore, it is determined that this proposal would not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that this 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) if promulgated, 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. A copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.

Start List of Subjects

List of Subjects in 14 CFR Part 39

End List of Subjects

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:

Start Part

PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Start Authority

Authority: 49 U.S.C. 106(g), 40113, 44701.

End Authority
[Amended]

2. Section 39.13 is amended by adding the following new airworthiness directive:

Boeing: Docket 2002-NM-12-AD.

Applicability: This AD applies to the following airplanes, certificated in any category, as identified in the applicable Boeing service bulletin specified in Table 1 of this AD:

Table 1—Applicability

Airplane modelBoeing service bulletin
737-600, -700, -700C, -800, -900 series airplanesSpecial Attention Service Bulletin 737-24-1165, Revision 1, dated October 20, 2005.
737-300, -400, -500 series airplanesAlert Service Bulletin 737-24A1166, Revision 3, dated July 25, 2007.
747-400, -400D, -400F series airplanesService Bulletin 747-24-2254, Revision 1, dated March 5, 2007.
757-200, -200CB, -200PF series airplanesSpecial Attention Service Bulletin 757-24-0110, dated April 28, 2005.
757-300 series airplanesSpecial Attention Service Bulletin 757-24-0111, dated April 28, 2005.
767-200, -300, -300F series airplanesSpecial Attention Service Bulletin 767-24-0160, dated June 30, 2005.
767-400ER series airplanesSpecial Attention Service Bulletin 767-24-0161, dated June 30, 2005.
777-200, -300, -300ER series airplanesService Bulletin 777-24-0095, Revision 1, dated January 3, 2007.

Compliance: Required as indicated, unless accomplished previously.

To prevent a standby static inverter from overheating, which could result in smoke in the flight deck and cabin and loss of the electrical standby power system, accomplish the following:

Modification

(a) At the time specified in paragraph (a)(1) or (a)(2) of this AD, as applicable: Modify the static inverter by removing resistor R170 from the logic control card assembly and replacing it with a new resistor, and relocating the new resistor to the solder side of the printed circuit board in accordance with the Accomplishment Instructions of the applicable service bulletin specified in Table 1 of this AD.

(1) For Model 737, 757, and 767 airplanes: Within 42 months after the effective date of this AD.

(2) For Model 747 and 777 airplanes: Within 60 months after the effective date of this AD.

Note 1:

The Boeing service bulletins specified in Table 1 of this AD refer to Avionic Instruments Inc. Service Bulletins 1-002-0102-1000-24-28, Revision A, dated June 22, 2005; and Revision B, dated July 24, 2006, as additional sources of service information for accomplishing the Start Printed Page 1164modification required by paragraph (a) of this AD.

Alternative Methods of Compliance

(b)(1) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Seattle ACO.

(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 appropriate principal inspector (PI) in the FAA Flight Standards District Office (FSDO), or lacking a PI, your local FSDO.

Start Signature

Issued in Renton, Washington, on December 18, 2008.

Stephen P. Boyd,

Assistant Manager, Transport Airplane Directorate, Aircraft Certification Service.

End Signature16 End Part End Supplemental Information

[FR Doc. E9-322 Filed 1-9-09; 8:45 am]

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