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 airplanes, that currently requires, among other actions, replacement of the existing air driven generator (ADG) wire assembly in the right air conditioning compartment with a certain new wire assembly. This action would require replacement of the ADG wiring and two associated clamps; inspection of the ADG wiring for correct wire identification, riding, and damage, and inspection of the associated routing/clamps for correct installation; and corrective actions if necessary. The actions specified by the proposed AD are intended to prevent loss of the charging capability of the airplane battery due to chafing. Loss of the charging capability of the airplane battery, coupled with a loss of all normal electrical power, could prevent continued safe flight and landing of the airplane. 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-75-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-75-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-75-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-75-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

On August 14, 2001, the FAA issued AD 2001-17-12, amendment 39-12403 (66 FR 44034, August 22, 2001), applicable to certain McDonnell Douglas Model MD-11 airplanes, to require, among other actions, replacement of the existing air driven generator (ADG) wire assembly in the right air conditioning compartment with a certain new wire assembly. That action was prompted by an investigation that revealed the length of the new wire assembly is too long and causes the assembly to chafe against the left emergency alternating current bus of the ADG. The requirements of that AD are intended to prevent loss of the charging capability of the airplane battery due to chafing. Loss of the charging capability of the airplane battery, coupled with a loss of all normal electrical power, could prevent continued safe flight and landing of the airplane.

Other Related Rulemaking

The FAA, in conjunction with Boeing and operators of Model MD-11 and -11F airplanes, has reviewed all aspects of the service history of those airplanes to identify potential unsafe conditions and to take appropriate corrective actions. This proposed AD is one of a series of corrective actions identified during that process. We have previously issued several other ADs and may consider further rulemaking actions to address the remaining identified unsafe conditions.

Actions Since Issuance of Previous Rule

Since the issuance of AD 2001-17-12, the airplane manufacturer has informed the FAA that, although previous revisions of Boeing Service Bulletin MD11-24-128 had the proper wire identification on the wire kits, Revision 03 of the service bulletin, as cited in AD 2001-17-12, had the wrong wire identification numbers. In addition, Revision 03 of the service bulletin did not provide procedures for verifying wire lengths to prevent any riding condition on the structure. Therefore, we have determined that the requirements of that AD do not adequately address the identified unsafe condition (i.e., loss of the charging capability of the airplane battery due to chafing).

Explanation of Relevant Service Information

We have reviewed and approved Revision 05 of Boeing Service Bulletin MD11-24-128, dated June 3, 2003. More work is necessary for airplanes changed as shown in previous revisions of this service bulletin. Revision 05 corrects wire identification numbers and wire data illustrations and adds procedures for verifying wire lengths. It describes the following procedures:

• Replacing the ADG wiring assembly located on the transformer panel at station Y=568.333 in the right air conditioning compartment with a new wire assembly; and replacing the associated clamps and screws of the ADG wire assembly with new clamps and screws;
• Torquing the terminal hardware to specified limits;
• Performing a general visual inspection of the ADG wire installation for damage/riding and correct clamping/routing;
• Performing a general visual inspection of the ADG wiring assembly for correct wire identification and/or damage; and
• Performing corrective actions if necessary.

The corrective actions include identifying wires; repairing or replacing wiring with new wiring; correcting wire clamping and routing; and repairing or replacing the wire assembly with a new assembly; as applicable.

Accomplishment of the actions specified in the service bulletin is intended to adequately 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 2001-17-12 to require accomplishment of the actions specified in Revision 05 of the service bulletin described previously.

Explanation of Change to Applicability

McDonnell Douglas Model MD-11F series airplanes were not specifically identified in the applicability of AD 2001-17-12 and are also not identified in the effectivity listing of Revision 05 of the service bulletin. However, those airplanes were identified by manufacturer's fuselage numbers (MFN) in Boeing Service Bulletin MD11-24-128, Revision 03, dated May 21, 2001 (which was referenced in the applicability statement of the AD for determining the specific affected airplanes), and are identified by MFNs in the effectivity listing of Revision 05 of the service bulletin. Therefore, we have revised the applicability of the existing 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 195 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 following table shows the estimated cost impact for airplanes affected by this proposed AD. The average labor rate is $65 per work hour.

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. The manufacturer may cover the cost of replacement parts associated with this proposed AD, subject to warranty conditions. Manufacturer warranty remedies may also be available for labor costs associated with this 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.