03-24847. Airworthiness Directives; McDonnell Douglas Model 717-200 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 Model 717-200 airplanes. This proposal would require repetitive inspections of the electric motor of the auxiliary hydraulic pump for electrical resistance, continuity, mechanical rotation, and associated wiring resistance/voltage; and corrective actions, if necessary. The actions are intended to prevent various failures of the electric motor 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. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by November 17, 2003.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2003-NM-55-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 [phone]. Comments may also be sent via the Internet using the following address: [e-mail]. Comments sent via fax or the Internet must contain “Docket No. 2003-NM-55-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 Aircraft Group, Long Beach Division, 3855 Lakewood Boulevard, Long Beach, California 98046, 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:

Albert Lam, Aerospace Engineer; Systems and Equipment Branch, ANM-130L, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; telephone [phone]; fax [phone].

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-55-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-55-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

The FAA has received reports that, during ground operations or when powered in flight by the air driven generator, the electric motor of the auxiliary hydraulic pump and associated motor feeder cables failed on certain McDonnell Douglas Model MD-80, MD-90, DC-10, and MD-11 series airplanes. 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 with the electric motor. Investigation revealed that these failures may be caused by hydraulic fluid contamination to the electric motor portion of the pump, a failed rotor bearing, and/or degradation of the stator's encapsulation material. Failure of the electric motors of the hydraulic pump and associated motor feeder cables, if not corrected, could result in a fire at the auxiliary hydraulic pump and consequent damage to the adjacent electrical equipment and/or structure.

The subject electric motor on certain McDonnell Douglas Model MD-80, MD-90, DC-10, and MD-11 series airplanes is identical to that on the affected Model 717-200 airplanes. Therefore, all of these models may be subject to the same unsafe condition.

Other Relevant Rulemaking

The FAA has previously issued AD 2001-22-17, amendment 39-12496 (66 FR 56753, November 13, 2001), applicable to certain McDonnell Douglas Model DC-9-81, -9-82, -9-83, and -9-87 series airplanes; Model MD-88 airplanes; and Model MD-90-30 series airplanes. We have also previously issued AD 2001-14-08, amendment 39-12319 (66 FR 36441, July 12, 2001), applicable to certain McDonnell Douglas Model DC-10 series airplanes, Model MD-10 series airplanes, and Model MD-11 series airplanes. These ADs require repetitive inspections of the electric motor of the auxiliary hydraulic pump for electrical resistance, continuity, mechanical rotation, and associated wiring resistance/voltage. Those ADs 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.

Explanation of Relevant Service Information

The FAA has reviewed and approved Boeing Alert Service Bulletin 717-29A0005, dated July 31, 2002, which describes procedures for repetitive inspections of the electric motor of the auxiliary hydraulic pump for electrical resistance, continuity, mechanical rotation, and associated wiring resistance/voltage; and corrective actions, if necessary. The corrective actions involve replacing the auxiliary hydraulic pump with a serviceable pump, troubleshooting, and repairing the wiring, as applicable.

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 bulletin described previously. Although the service bulletin referenced in this AD specifies to submit certain information to the manufacturer, this AD does not include such a requirement.

Interim Action

This is considered to be interim action until final action is identified, at which time the FAA may consider further rulemaking.

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). Because we have now included this material in part 39, only the office authorized to approve AMOCs is identified in each individual AD.

Change to Labor Rate Estimate

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 95 airplanes of the affected design in the worldwide fleet. The FAA estimates that 67 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 1 work hour 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 proposed AD on U.S. operators is estimated to be $4,355, or $65 per airplane, per inspection cycle.

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 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.

§ 39.13

[Amended]

2. Section 39.13 is amended by adding the following new airworthiness directive:

McDonnell Douglas: Docket 2003-NM-55-AD.

Applicability: Model 717-200 airplanes, manufacturer's fuselage numbers 5002 through 5200 inclusive, certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent various failures of electric motor 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, accomplish the following:

Service Bulletin References

(a) The term “service bulletin,” as used in this AD, means the Accomplishment Instructions of Boeing Alert Service Bulletin 717-29A0005, dated July 31, 2002. Although the service bulletin referenced in this AD specifies to submit certain information to the manufacturer, this AD does not include such a requirement.

Initial Inspection and Testing

(b) Prior to the accumulation of 3,000 total flight hours, or within 12 months after the effective date of this AD, whichever occurs later, do an inspection of the electric motor of the auxiliary hydraulic pump for electrical resistance, continuity, mechanical rotation, and associated writing resistance/voltage per the service bulletin.

Condition 1, No Failures: Repetitive Inspections

(c) If no failures are detected during any inspection required by paragraph (b) of this AD, repeat the inspection thereafter at intervals not to exceed 5,000 flight hours.

Condition 2, Failure of Any Pump Motor: Replacement and Repetitive Inspections

(d) If any pump motor fails during any inspection required by paragraph (b) of this AD, before further flight, replace the failed auxiliary hydraulic pump with a serviceable pump, per the service bulletin. Repeat the inspection required by paragraph (b) of this AD at intervals not to exceed 5,000 flight hours.

Condition 3, Failure of Any Wiring: Repair and Repetitive Inspection

(e) If any wiring fails during any inspection required by paragraph (b) of this AD, before further flight, troubleshoot and repair the failed wiring, per the service bulletin. Repeat the inspection at intervals not to exceed 5,000 flight hours.

Alternative Methods of Compliance

(f) In accordance with 14 CFR 39.19, the Manager, Los Angeles Aircraft Certification Office, FAA, is authorized to approve alternative methods of compliance (AMOCs) for this AD.

Issued in Renton, Washington, on September 24, 2003.

Ali Bahrami,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.