Airworthiness Directives; McDonnell Douglas Model DC-10-10, DC-10-10F, DC-10-15, DC-10-30, DC-10-30F (KC-10A and KDC-10), DC-10-40, DC-10-40F, MD-10-10F, MD-10-30F, MD-11, and MD-11F Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain McDonnell Douglas airplanes as listed above. This proposal would require modification of the installation wiring for the electric motor operated auxiliary hydraulic pumps in the right wheel well area of the main landing gear, and repetitive inspections of the number 1 and 2 electric motors of the auxiliary hydraulic pumps for electrical resistance, continuity, mechanical rotation, and associated airplane wiring resistance/voltage; and corrective actions if necessary. This action is necessary to prevent failure of the electric motors of the hydraulic pump and associated wiring, which could result in fire at the auxiliary hydraulic pump and consequent damage to the adjacent electrical equipment and/or structure. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by December 1, 2003.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-362-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. 2001-NM-362-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 for Windows or ASCII text.

The service information referenced in the proposed rule may be obtained from Boeing Commercial Aircraft Group, Long Beach Division, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Technical Publications Business Administration, Dept. C1-L51 (2-60). 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:

Ken Sujishi, Aerospace Engineer, Systems and Equipment Branch, ANM-130L, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712; telephone (562) 627-5353; 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 2001-NM-362-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. 2001-NM-362-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

The FAA has received several reports of failure of the auxiliary hydraulic pump systems on Model DC-10 airplanes. Some failures resulted in burnt electrical wiring leading to the electric motor of the auxiliary hydraulic pump, within the right wheel well area of the main landing gear (MLG). Damage also was found on the adjacent structure, control cables, hydraulic pipes, and hoses. These failures occurred during ground operations, or when powered in-flight by the air-driven generator. The failures were due to an electrical short within the electric motor which resulted in arcing damage. These failures consisted of a seized or difficult-to-turn rotor on the pump assembly, burnt and shorted motor feeder cables, and/or uncontained internal electric arcing failures within the electric motor. Investigation revealed that these conditions occurred on airplanes that had been in service several years and/or had the auxiliary hydraulic pump previously overhauled. These discrepancies can be caused by hydraulic fluid contamination to the electric motor portion of the pump assembly which causes failed rotor bearing, and/or degradation of the stator's encapsulate material. Such discrepancies, if not corrected, could result in fire at the auxiliary hydraulic pump and consequent damage to the adjacent electrical equipment and/or structure.

Explanation of Relevant Service Information

We have reviewed and approved Boeing Alert Service Bulletin DC10-29A144, Revision 2, dated August 1, 2003 (for Model DC-10-10, DC-10-10F, DC-10-15, DC-10-30, DC-10-30F (KC-10A and KDC-10), DC-10-40, DC-10-40F, MD-10-10F, and MD-10-30F airplanes), which describes procedures for modification of the electrical wiring of the auxiliary hydraulic pump installation in the right wheel well area of the MLG. The modification includes, but is not limited to, removing existing clamps, ground wires (if required), and sleeving from the wire assemblies; inspecting for cracks and chafing, installing new support brackets, clips, and bracket assemblies, as applicable; installing sleeving; re-routing the wire assemblies using new clamps and attachments, installing an additional routing clip on the lower bracket of the fuel motor control valve, if applicable, and doing a voltage check and a functional test.

Service Bulletin DC10-29A144 recommends prior or concurrent accomplishment of Boeing Alert Service Bulletin DC10-29A142, Revision 02, dated April 17, 2003, which describes procedures for repetitive inspections (checks) of the number 1 and 2 electric motors of the auxiliary hydraulic pumps for electrical resistance, continuity, mechanical rotation, and associated airplane wiring resistance/voltage, and corrective actions if necessary. The corrective actions include replacing the auxiliary hydraulic pump with a serviceable pump, and repairing the wiring.

We also have reviewed and approved Boeing Alert Service Bulletin MD11-29A059, Revision 2, dated August 1, 2003 (for Model MD-11 and MD-11F airplanes), which describes procedures for modification of the wiring of the electric motors of the auxiliary hydraulic pump in the right wheel well area of the MLG. The modification includes, but is not limited to, removing and retaining wire assembly clamps, if applicable; retaining the existing ground wire assemblies; retaining or replacing all other wire assemblies for both connectors; installing spiral wrap and sleeving; wrapping upper ends of individual wires with tape; installing new support bracket assemblies, if applicable; re-routing and attaching wire assemblies using new clamps and attachments, if applicable; and doing a voltage check and a functional test.

Service Bulletin MD11-29A059 recommends prior or concurrent accomplishment of Boeing Alert Service Bulletin MD11-29A057, Revision 02, dated April 17, 2003, which describes procedures for repetitive inspections (checks) of the number 1 and 2 electric motors of the auxiliary hydraulic pumps for electrical resistance, continuity, mechanical rotation, associated airplane wiring resistance/voltage, and corrective actions if necessary. The corrective actions include replacing the auxiliary hydraulic pump with a serviceable pump and repairing the wiring.

Accomplishment of the actions specified in the service bulletins is intended to adequately address the identified unsafe condition.

Related Rulemaking

On July 2, 2001, we issued AD 2001-14-08, amendment 39-12319 (66 FR 36441, July 12, 2001), for certain McDonnell Douglas Model DC-10 series airplanes, Model MD-10 series airplanes, and Model MD-11 series airplanes. That AD requires repetitive inspections of the number 1 and 2 electric motors of the auxiliary hydraulic pump for electrical resistance, continuity, mechanical rotation, and associated wiring resistance/voltage; and corrective actions if necessary. The actions specified by that AD are intended to prevent various failures of electric motors of the auxiliary hydraulic pump and associated wiring, which could result in fire at the auxiliary hydraulic pump and consequent damage to the adjacent electrical equipment and/or structure. That AD is being superseded by a separate action to reduce the repetitive inspection intervals currently required.

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 require accomplishment of the actions specified in the service bulletins described previously, except that the proposed AD does not require completing the Evaluation Forms.

Cost Impact

There are approximately 409 Model DC-10 airplanes of the affected design in the worldwide fleet. The FAA estimates that 322 airplanes of U.S. registry would be affected by this proposed AD.

It would take approximately 9 work hours per airplane to do the modification specified in Service Bulletin DC10-29A144, at an average labor rate of $65 per work hour. Required parts would cost would be between $4,886 and $7,920 per airplane. Based on these figures, the cost impact of the proposed modification is estimated to be between $5,471 and $8,505 per airplane.

It would take approximately 1 work hour per airplane to do the inspection specified in Service Bulletin DC10-29A142, at an average labor rate of $65 per work hour. Based on these figures, the cost impact of the proposed inspection is estimated to be $65 per airplane, per inspection cycle.

There are approximately 195 Model MD-11 airplanes of the affected design in the worldwide fleet. The FAA estimates that 74 airplanes of U.S. registry would be affected by this proposed AD.

It would take approximately 13 work hours per airplane to do the modification specified in Service Bulletin MD11-29A059, at an average labor rate of $65 per work hour. Required parts would cost between $5,183 and $9,182 per airplane. Based on these figures, the cost impact of the proposed modification is estimated to be between $6,028 and $10,027 per airplane.

It would take approximately 1 work hour per airplane to do the inspection specified in Service Bulletin MD11-29A057, at an average labor rate of $65 per work hour. Based on these figures, the cost impact of the proposed inspection is estimated to be $65 per airplane, per inspection cycle.

The cost impact figures discussed above are 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 this proposed 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.

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.