Airworthiness Directives; The Boeing Company Model 777-200, -200LR, -300, and -300ER Series Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

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

SUMMARY:

We are revising an earlier proposed airworthiness directive (AD) for certain Model 777-200, -200LR, -300, and -300ER series airplanes. The original NPRM would have required doing an inspection to identify the part number of the motor operated valve (MOV) actuators of the main and center fuel tanks; replacing certain MOV actuators with new MOV actuators; and measuring the electrical resistance of the bond from the adapter plate to the airplane structure, and doing corrective actions if necessary. The original NPRM also would have required revising the Airworthiness Limitations section of the Instructions for Continued Airworthiness. The original NPRM resulted from fuel system reviews conducted by the manufacturer. This action revises the original NPRM by adding airplanes to the applicability. This action also revises the original NPRM by removing the requirement for revising the Airworthiness Limitations section of the Instructions for Continued Airworthiness. We are proposing this supplemental NPRM to prevent electrical current from flowing through an MOV actuator into a fuel tank, which could create a potential ignition source inside the fuel tank. This condition, in combination with flammable fuel vapors, could result in a fuel tank explosion and consequent loss of the airplane.

DATES:

We must receive comments on this supplemental NPRM by January 18, 2011.

ADDRESSES:

You may send comments by any of the following methods:

• Federal eRulemaking Portal: Go to http://www.regulations.gov . Follow the instructions for submitting comments.
• Fax: 202-493-2251.
• Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590.
• Hand Delivery: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this proposed AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P. O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone 206-544-5000, extension 1; fax 206-766-5680; e-mail me.boecom@boeing.com; Internet https://www.myboeingfleet.com . You may review copies of the referenced service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information on the availability of this material at the FAA, call 425-227-1221.

Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.gov;; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Office (telephone 800-647-5527) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

Tak Kobayashi, Aerospace Engineer, Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6499; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or arguments about this proposed AD. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2008-0847; Directorate Identifier 2008-NM-056-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed AD because of those comments.

We will post all comments we receive, without change, to http://www.regulations.gov,, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this proposed AD.

Discussion

We issued a notice of proposed rulemaking (NPRM) (the “original NPRM”) to amend 14 CFR part 39 to include an airworthiness directive (AD) that would apply to certain Model 777-200, -200LR, -300, and -300ER series airplanes. That original NPRM was published in the Federal Register on August 7, 2008 (73 FR 45893). That original NPRM proposed to require doing an inspection to identify the part number of the motor operated valve (MOV) actuators of the main and center fuel tanks; replacing certain MOV actuators with new MOV actuators; and measuring the electrical resistance of the bond from the adapter plate to the airplane structure, and doing corrective actions if necessary. The original NPRM also would have required revising the Airworthiness Limitations section of the Instructions for Continued Airworthiness (ICA).

Actions Since Original NPRM Was Issued

Since we issued the original NPRM, the manufacturer has informed us that certain airplanes were missing from the effectivity in Boeing Alert Service Bulletin 777-28A0034, dated August 2, 2007, which was referenced in the original NPRM as the appropriate source of service information.

In addition, since we issued the original NPRM, we have determined that the proposed requirement for revising the Airworthiness Limitations (AWL) section of the ICA is unnecessary. Incorporation of AWL No. 28-AWL-19 and AWL No. 28-AWL-20 is already mandated by AD 2008-11-13, Amendment 39-15536 (73 FR 30737, May 29, 2008), which is applicable to Model 777-200, -200LR, -300, and -300ER series airplanes. Therefore, we have removed Note 1 and paragraphs (h), (i), and (j) from the original NPRM.

Relevant Service Information

Since the issuance of the original NPRM, we reviewed Boeing Alert Service Bulletin 777-28A0034, Revision 1, dated May 20, 2010, which adds airplanes to the effectivity, and corrects an MOV actuator part number. We also reviewed Boeing Service Bulletin 777-28A0034, Revision 2, dated September 20, 2010, which specifies to cap seal the bonding jumper fasteners when installing the MOV actuator. Boeing Service Bulletin 777-28A0034, Revision 2, dated September 20, 2010, specifies that no more work is necessary on airplanes modified in accordance with Boeing Alert Service Bulletin 777-28A0034, dated August 2, 2007; and Revision 1, dated May 20, 2010.

We have revised paragraphs (c), (g), and (h) of this supplemental NPRM to refer to Boeing Service Bulletin 777-28A0034, Revision 2, dated September 20, 2010. In addition, we have added new paragraph (j) to this supplemental NPRM to provide credit for actions accomplished before the effective date of this AD in accordance with Boeing Alert Service Bulletin 777-28A0034, dated August 2, 2007; and Revision 1, dated May 20, 2010.

Comments

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

Request To Use Later Revisions of the Maintenance Planning Data (MPD) Document

Boeing, and Air Transport Association (ATA) on behalf of its member United Airlines (UAL), requested that the FAA reference later revisions of the MPD document in paragraph (h) of the original NPRM.

As stated previously, we have removed paragraph (h) (the requirement to revise the AWL section of the ICA) of the original NPRM. Therefore, no revision to this supplemental NPRM is necessary in this regard.

Allow the Use of Later Revisions of Alternative Critical Design Configuration Control Limitations (CDCCLs)

ATA, on behalf of its member UAL, stated that paragraph (i) of the original NPRM should include instructions similar to those in paragraph (i) of AD 2008-11-13, which allows operators to use alternative “CDCCLs that are part of a later revision of February 2008 of the MPD” that is approved by the FAA to avoid confusion and to promote common compliance rules.

As stated previously, we have removed paragraph (i) of the original NPRM. Therefore, no revision to this supplemental NPRM is necessary in this regard.

Request To Revise the Costs of Compliance

Boeing, and ATA on behalf of its member UAL, requested that we revise the Costs of Compliance section in the original NPRM to include the cost of parts. ATA stated that the cost of parts presents a significant expense to the operators since there are 11 MOV actuators on each of the 197 airplanes affected by the original NPRM, costing $5,477 per actuator. Boeing stated that the cost of parts is substantial and, when accounted alongside with the cost of labor, estimated work-hours, and the total number of affected airplanes, the cost would be higher than what is stated in the original NPRM.

We agree to include the cost of parts in this supplemental NPRM. We have revised the Costs of Compliance section accordingly.

Request To Clarify the Accomplishment Instructions in the Service Bulletin

ATA, on behalf of its member UAL, requested clarification of the Accomplishment Instructions in Boeing Alert Service Bulletin 777-28A0034, dated August 2, 2007. UAL asserted that the logical flow (“if—then” condition) of the installation instructions is incomplete and can be further clarified. UAL also stated that certain Boeing 777 aircraft maintenance manuals referenced as sources of guidance in Boeing Alert Service Bulletin 777-28A0034, dated August 2, 2007, have two sections, “Pre” and “Post” Boeing Alert Service Bulletin 777-28A0034, and that the service bulletin should specify which section is applicable.

We agree with UAL that some of the instructions in Boeing Alert Service Bulletin 777-28A0034, dated August 2, 2007, are unclear. Those issues have been clarified in Boeing Alert Service Bulletin 777-28A0034, Revision 1, dated May 20, 2010; and Boeing Service Bulletin 777-28A0034, Revision 2, dated September 20, 2010. As stated previously, we have revised this supplemental NPRM to refer to Boeing Service Bulletin 777-28A0034, Revision 2, dated September 20, 2010, and to provide credit for accomplishment of Boeing Alert Service Bulletins 777-28A0034, dated August 2, 2007, and to Revision 1, dated May 20, 2010, before the effective date of the AD.

Request To Prohibit the Installation of Part Number (P/N) MA20A1001-1

ATA, on behalf of its member UAL, expressed that the intent of the original NPRM is to remove the MOV actuator having P/N MA20A1001-1 and to prohibit installation of P/N MA20A1001-1 once the AD has been complied with. UAL stated that it has reviewed the NPRM and cannot find language that prohibits the installation of P/N MA20A1001-1; UAL stated that such language should be in this proposed AD.

We partially agree. We disagree that it is necessary to specifically prohibit the installation of P/N MA20A1001-1 once the AD has been complied with because after accomplishing the mandatory actions, operators are required to maintain airplanes in compliance with the AD. To ensure that the unsafe condition cannot be introduced before compliance with the AD, we have added paragraph (i) to this supplemental NPRM to prohibit installation of an MOV actuator, P/N MA20A1001-1, after the effective date of this AD.

Request To Postpone the AD or Extend the Compliance Time

ATA, on behalf of its member UAL, requested that the FAA postpone the proposed AD or extend the compliance time until reliability issues pertaining to the MOV actuator with P/N MA30A1001 are resolved. UAL stated that Boeing Fleet Team Digest 737NG-FTD-28-07002 discusses the potential of the P/N MA30A1001 actuator having cracked or damaged capacitors. UAL stated that if the MOV actuators with the defective design are installed due to regulatory mandate, the opportunity of actuator failure is introduced, which creates unnecessary economic burden for operators.

We disagree with UAL's request to postpone the AD or extend the compliance time. The problem of the capacitor does not constitute a new unsafe condition. The investigation conducted by the supplier of the affected MOV actuators concluded that damage to the capacitors was introduced due to certain manufacturing processes. To address this issue, the supplier changed manufacturing processes in March 2007. We are aware that a number of MOV actuators that were produced under the manufacturing processes before that change were returned to the supplier between December 2006 and October 2007. Boeing also informed us that no actuators have been returned to the supplier due to damaged capacitors since October 2007. We have determined that the manufacturing process changes have adequately addressed the reliability issues; therefore, the current inventory of spare MOV actuators would be unlikely to contain a discrepant part. We consider it inappropriate to delay this AD since we have determined that an unsafe condition exists and that replacement of certain parts must be accomplished to ensure continued safety. We have not changed this supplemental NPRM in this regard.

FAA's Determination and Proposed Requirements of the Supplemental NPRM

We are proposing this supplemental NPRM because we evaluated all pertinent information and determined an unsafe condition exists and is likely to exist or develop on other products of the same type design. Certain changes described above expand the scope of the original NPRM. As a result, we have determined that it is necessary to reopen the comment period to provide additional opportunity for the public to comment on this supplemental NPRM.

Additional Changes to the Original NPRM

In the Costs of Compliance section in the original NPRM, 197 airplanes were estimated to be affected. The correct number of affected airplanes in this supplemental NPRM is 127 airplanes. We have revised the Costs of Compliance section accordingly.

We have determined that a review of airplane records will be adequate to identify the MOV actuator part number. Therefore, we have added a records review as an option to the inspection in paragraph (g) of this supplemental NPRM (paragraph (f) in the original NPRM).

We have revised paragraph (h) of this supplemental NPRM (paragraph (g)(1) in the original NPRM) to specify the correct replacement actuator part number. We have also revised paragraph (h) of this supplemental NPRM to allow the installation of a serviceable MOV actuator. In addition, we have revised paragraph (h) of this supplemental NPRM to clarify that measuring the electrical resistance of the bond from the adapter plate is only required at certain MOV actuator locations.

We have added a new paragraph (d) to this supplemental NPRM to provide the Air Transport Association of America (ATA) Code 28, Fuel. This code is added to make this supplemental NPRM parallel with other new AD actions. We have reidentified subsequent paragraphs accordingly.

We have revised this AD to identify the legal name of the manufacturer as published in the most recent type certificate data sheet for the affected airplane models.

Costs of Compliance

We estimate that this proposed AD will affect 127 airplanes of U.S. registry. We estimate the following costs to comply with this proposed AD:

We estimate the following costs to do any necessary replacements that would be required based on the results of the proposed inspection. We have no way of determining the number of aircraft that might need these replacements.

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 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 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. Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.

You can find our regulatory evaluation and the estimated costs of compliance in the AD Docket.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Incorporation by reference
• Safety

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.