Airworthiness Directives; McDonnell Douglas Model MD-11 and -11F Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the supersedure of an existing airworthiness directive (AD), applicable to certain McDonnell Douglas Model MD-11 and -11F airplanes, that currently requires repetitive inspections to verify operation of the remote control circuit breakers (RCCB) of the alternating current (AC) cabin bus switch, and replacement of any discrepant RCCB with a new RCCB. This action would require the existing actions per a later service bulletin revision. The actions specified by the proposed AD are intended to prevent propagation of smoke and fumes in the cockpit and passenger cabin due to an inoperable RCCB of the AC cabin bus switch during smoke and fume isolation procedures. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by May 17, 2004.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2003-NM-76-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. 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. 2003-NM-76-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 Airplanes, Long Beach Division, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Data and Service Management, Dept. C1-L5A (D800-0024). This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California.

FOR FURTHER INFORMATION CONTACT:

Brett Portwood, Aerospace Engineer, Systems and Equipment Branch, ANM-130L, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; telephone (562) 627-5350; fax (562) 627-5210.

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 2003-NM-76-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. 2003-NM-76-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

On July 28, 2000, the FAA issued AD 2000-15-14, amendment 39-11846 (65 FR 48362, August 23, 2000), applicable to certain McDonnell Douglas Model MD-11 and -11F airplanes, to require repetitive inspections to verify operation of the remote control circuit breakers (RCCB) of the alternating current (AC) cabin bus switch, and replacement of any discrepant RCCB with a new RCCB. That action was prompted by incidents in which certain RCCBs of the AC cabin bus switch failed when the switch was pushed to the “OFF” position. The requirements of that AD are intended to prevent propagation of smoke and fumes in the cockpit and passenger cabin due to an inoperable RCCB of the AC cabin bus switch during smoke and fume isolation procedures.

Actions Since Issuance of Previous Rule

Since the issuance of that AD, the airplane manufacturer has informed the FAA that Boeing Alert Service Bulletin MD11-24A181, dated June 27, 2000 (referenced in AD 2000-15-14 as the appropriate source of service information for the required actions), specifies correct “Item Numbers” for the affected RCCBs, but for some airplane groups, specifies wrong part numbers. As a result, operators may not have inspected all of the affected RCCBs. Therefore, we have determined that it is necessary to reinspect all RCCBs.

Explanation of Relevant Service Information

The FAA has reviewed and approved Revision 1 of Boeing Alert Service Bulletin MD11-24A181, dated July 11, 2003. The repetitive inspections and corrective actions if necessary in this revision are identical to those described in the original issue of the service bulletin. Revision 1 changes group effectivity for 72 airplanes and adds disposition recommendations for failed RCCBs. Accomplishment of the actions specified in the service bulletin is intended to address the identified unsafe condition.

Explanation of Requirements of Proposed Rule

Since an unsafe condition has been identified that is likely to exist or develop on other products of this same type design, the proposed AD would supersede AD 2000-15-14 to continue to require repetitive inspections to verify operation of the RCCBs of the AC cabin bus switch, and replacement of any discrepant RCCB with a new RCCB. The proposed AD also would require accomplishment of the actions specified in Revision 1 of the service bulletin described previously, except as discussed below. Accomplishment of the initial inspection per Revision 1 ends the existing repetitive inspections, which are done per the original issue of the service bulletin.

Difference Between Proposed Rule and Referenced Service Bulletin

Operators should note that, although the Accomplishment Instructions of the referenced service bulletin describe procedures for sending failed RCCBs to the circuit breaker manufacturer for analysis and for reporting inspection findings and the result of the analysis to the airplane manufacturer, this proposed AD would not require those actions. The FAA does not need this information from operators.

Explanation of Change to Applicability

We have revised the applicability of the existing AD to reference Revision 1 of the service bulletin as the appropriate source of service information. As discussed above, the effectivity listing of this revision specifies the current groupings of affected airplanes.

In addition, McDonnell Douglas Model MD -11F series airplanes were not specifically identified in the applicability of AD 2000-15-14. However, those airplanes were identified by manufacturer's fuselage numbers (MFN) in Boeing Alert Service Bulletin MD11-24A181, dated June 27, 2000 (which was referenced in the applicability statement of the AD for determining the specific affected airplanes). Therefore, we have revised the applicability of the proposed AD to identify model designations as published in the most recent type certificate data sheet for the affected models (i.e., Model MD -11 and -11F airplanes).

Cost Impact

There are approximately 197 airplanes of the affected design in the worldwide fleet. The FAA estimates that 81 airplanes of U.S. registry would be affected by this proposed AD.

The actions that are currently required by AD 2000-15-14 take approximately 1 work hour per airplane to accomplish, at an average labor rate of $65 per work hour. Based on these figures, the cost impact of the currently required actions on U.S. operators is estimated to be $5,265, or $65 per airplane, per inspection cycle.

The new actions that are proposed in this AD action would take approximately 1 or 2 work hours per airplane (depending on airplane configuration) to accomplish, at an average labor rate of $65 per work hour. Based on these figures, the cost impact of the proposed inspection requirements of this AD on U.S. operators is estimated to be $65 or $130 per airplane (depending on airplane configuration), per inspection cycle.

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the current or proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this AD 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. Manufacturer warranty remedies may be available for labor costs associated with this proposed AD. As a result, the costs attributable to the proposed AD may be less than stated above.

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.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

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:

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.