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

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Supplemental notice of proposed rulemaking; reopening of comment period.

SUMMARY:

This document revises an earlier proposed airworthiness directive (AD), applicable to certain McDonnell Douglas Model MD-11 and -11F airplanes, that would have required resistance tests of the brake coils of the auto throttle servo (ATS) and of the elevator load feel (ELF)/flap limiter (FL) duplex actuator for low electrical resistance; and corrective actions, if necessary. This new action revises the proposed rule by removing the resistance tests, adding certain airplanes to the applicability, and adding an inspection of the ATS assembly and corrective actions if necessary. The actions specified by this new proposed AD are necessary to prevent electrical shorting of the brake coils of the ATS, which could result in smoke in the cockpit and/or passenger cabin. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by August 9, 2004.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2000-NM-32-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. 2000-NM-32-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 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 2000-NM-32-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. 2000-NM-32-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

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 McDonnell Douglas Model MD-11 and -11F airplanes, was published as notice of proposed rulemaking (NPRM) in the Federal Register on July 27, 2000 (65 FR 46210) (hereafter referred to as the “original NPRM”). The original NPRM would have required resistance tests of the brake coils of the auto throttle servo (ATS) and of the elevator load feel (ELF)/flap limiter (FL) duplex actuator for low electrical resistance; and corrective actions, if necessary. The original NPRM was prompted by an incident in which the ATS shorted electrically and caused smoke in the cockpit. Electrical shorting of the brake coils of the ATS or ELF/FL duplex actuator, if not corrected, could result in smoke in the cockpit and/or passenger cabin.

Actions Since the Issuance of Original NPRM

Since the issuance of the original NPRM, we have reviewed and approved Boeing Service Bulletin MD11-22-026, dated December 19, 2003. The service bulletin supersedes and cancels the recommendations of Boeing Service Bulletins MD11-22-024 and MD11-22-025 (original and Revision 01). The service bulletin describes procedures for performing an inspection to determine the P/N of the ATS assembly of the servo assembly of the TCM, and corrective action(s) if necessary. The corrective actions include reidentifying the TCM assembly; and replacing the existing ATS assembly of the TCM assembly with a new ATS assembly or returning the TCM assembly in the center of the pedestal in the flight compartment to Boeing for modification and reidentification. Accomplishment of the actions specified in the Boeing Service Bulletin MD11-22-026 is intended to adequately address the identified unsafe condition. Therefore, we have revised the supplemental NPRM to reference Boeing Service Bulletin MD11-22-026 as the appropriate source of service information.

Comments

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

Request To Change Dash Number of Affected Spare Parts

Two commenters request that the FAA require Boeing and Honeywell to change the dash numbers on all parts affected by the original NPRM. To do this, one commenter suggests that the manufacturers' revise the following service information:

1. Boeing Service Bulletin MD11-22-024, dated March 29, 2000 (which is referenced in the original NPRM as the appropriate source of service information for accomplishing the proposed actions);

2. Honeywell Service Bulletins 4059004-22-0003 and 4059005-27-0004 (Boeing Service Bulletin MD11-22-024 references these Honeywell service bulletins as an additional source of service information for accomplishing the proposed resistance tests);

3. Boeing Component Maintenance Manuals (CMM) 76-10-05; and

4. Honeywell CMMs 22-31-60 and 27-32-07.

Several commenters note that paragraph (b) of the original NPRM states, “As of the effective date of this AD, no person shall install the following parts on any airplane: (1) Thrust control module assembly having part number ABH7760-1, ABH7760-501, or ABH7760-503; (2) Flap limiter duplex actuator having part number 4059004-901; or (3) Elevator load feel duplex actuator having part number 4059005-901.” Two of the commenters state that none of the service information listed above recommend re-identification of thrust control module (TCM) assembly having part number ABH7760-1, ABH7760-501, or ABH7760-503, but do recommend re-identification with a modication letter “K” after the resistance tests of ATSs having part number (P/N) 4059004-901—a subassembly of the TCM, and ELF/FL duplex actuators having P/N 4059005-901. Another commenter made a similar statement. One of the commenters specifically points out that P/N 4059004-901 in paragraph (b)(2) of the original NPRM actually belongs to the ATS, which is the subassembly of the TCM, and that P/N 4059005-901 in paragraph (b)(3) of the original NPRM applies to both the ELF and FL installations.

One of the commenters notes that re-identification per a modification letter does not constitute a part number change, and that parts are not purchased, stocked, tracked, or identified in an airplane illustrated parts catalog using modification letters. Therefore, the commenter concludes that a modification letter change will do very little to help prevent pre-modification parts from being installed on an airplane.

In addition, one commenter requests that provisions be added to Boeing Service Bulletin MD11-22-024 to allow operators to perform the resistance check on all affected spares without special routings to shop for complete disassembly and date code checks. The commenter states that spares should be reidentified with the new dash number and returned to stock provided they pass all resistance checks.

The FAA does not agree with the commenters' request to require Boeing and Honeywell to update the respective CMMs. Because CMMs are not FAA-approved and the procedures specified in CMMs vary from operator to operator, there are no assurances that each operator's CMM contains the identical actions proposed by this supplemental NPRM. These changes should be negotiated between the affected operators and Boeing.

However, we agree with the commenter's statement that the Boeing and Honeywell service bulletins listed above need to be revised, but for different reasons. Since the issuance of the original NPRM, we have determined that the ELF/FL duplex actuators are not subject to the identified unsafe condition of this AD. These actuators are installed outside of the cockpit and passenger cabin such that the possibility of smoke in the cockpit or cabin is minimized. Also, we have determined that all ATSs that have not been upgraded to P/N 4059005-903 are subject to electrical shorting, and that the proposed resistance tests in the original NPRM are not adequate to detect all defective ATSs. Therefore, all ATSs must be inspected to determine if they have been upgraded to P/N 4059005-903 per Boeing Service Bulletin MD11-22-026 (described previously).

Explanation of Change to Applicability

We have determined that some confusion may arise from the applicability of the original NPRM, because McDonnell Douglas Model MD-11F series airplanes were not specifically identified. However, those airplanes were identified by manufacturer's fuselage numbers in Boeing Service Bulletin MD11-22-024, dated March 29, 2000 (which was referenced in the applicability statement of the original NPRM for determining the specific affected airplanes). Therefore, we have revised the applicability of the supplemental NPRM to include Model MD-11F airplanes, in addition to Model MD-11 series airplanes, and to reference Boeing Service Bulletin MD11-22-026 as the appropriate source of service information for determining the specific affected airplanes.

Conclusion

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

Changes to 14 CFR Part 39/Effect on the Proposed AD

On July 10, 2002, the FAA issued a new version of 14 CFR part 39 (67 FR 47997, July 22, 2002), which governs the FAA's airworthiness directives system. The regulation now includes material that relates to altered products, special flight permits, and alternative methods of compliance (AMOCs). These changes are reflected in this supplemental NPRM.

Changes to Labor Rate

We have reviewed the figures we have used over the past several years to calculate AD costs to operators. To account for various inflationary costs in the airline industry, we find it necessary to increase the labor rate used in these calculations from $60 per work hour to $65 per work hour. The cost impact information, below, reflects this increase in the specified hourly labor rate.

Cost Impact

There are approximately 195 McDonnell Douglas Model MD-11 and “11F airplanes of the affected design in the worldwide fleet. The FAA estimates that 62 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 1 work hours per airplane to accomplish the proposed inspection, and that the average labor rate is $65 per work hour. Based on these figures, the cost impact of the inspection proposed by this AD on U.S. operators is estimated to be $4,030, or $65 per airplane.

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 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.

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.