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

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 94-NM-26-AD]

Airworthiness Directives; McDonnell Douglas Model DC-10-10, -15,

-30, and -40 Series Airplanes, KC-10A (Military) Airplanes, and Model

MD-11 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness

directive (AD) that is applicable to certain McDonnell Douglas Model

DC-10 and MD-11 series airplanes. This proposal would require the

installation of retainers and supports at the lateral control mixer

bracket on the center of the wing rear spar of the airplane. This

proposal is prompted by an analysis conducted by the manufacturer,

which revealed that failure of a lateral control mixer bracket could

result in uncommanded deployment of the spoiler. The actions specified

by the proposed AD are intended to prevent inadvertent asymmetric

deployment of the spoiler, which may lead to reduced controllability of

the airplane.

DATES: Comments must be received by August 1, 1994.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

Administration (FAA), Transport Airplane Directorate, ANM-103,

Attention: Rules Docket No. 94-NM-26-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.

The service information referenced in the proposed rule may be

obtained from McDonnell Douglas Corporation, P.O. Box 1771, Long Beach,

California 90801-1771, Attention: Business Unit Manager, Technical

Administrative Support, Department L51, M.C. 2-98. This information may

be examined at the FAA, Transport Airplane Directorate, 1601 Lind

Avenue, SW., Renton, Washington; or at the FAA, Transport Airplane

Directorate, Los Angeles Aircraft Certification Office, 3229 East

Spring Street, Long Beach, California.

FOR FURTHER INFORMATION CONTACT: Wahib Mina, Aerospace Engineer,

Airframe Branch, ANM-121L, FAA, Transport Airplane Directorate, Los

Angeles Aircraft Certification Office, 3229 East Spring Street, Long

Beach, California 90806-2425; telephone (310) 988-5324; fax (310) 988-

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 notice may be changed in

light of the comments received.

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 notice must submit a self-addressed,

stamped postcard on which the following statement is made: ``Comments

to Docket Number 94-NM-26-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-103, Attention: Rules

Docket No. 94-NM-26-AD, 1601 Lind Avenue, SW., Renton, Washington

98055-4056.

Discussion

A recent analysis conducted by the manufacturer revealed that the

potential exists for uncommanded spoiler extension due to failure, for

any reason, of a lateral control mixer bracket on Model MD-11 series

airplanes. The FAA has reviewed the results of this analysis and has

determined that failure of the lateral control mixer bracket could

result in uncommanded deployment of the spoiler on Model DC-10-10, -15,

-30, and -40 series airplanes, and KC-10A (military) airplanes, as well

as on Model MD-11 series airplanes, since the brackets are designed

similarly on these airplanes. This condition, if not corrected, could

result in inadvertent asymmetric deployment of the spoiler, which may

lead to reduced controllability of the airplane.

The FAA has reviewed and approved McDonnell Douglas DC-10 Service

Bulletin 27-222 [for Model DC-10-10, -15, -30, and -40 series airplanes

and KC-10 (military) airplanes], and MD-11 Service Bulletin 27-34 (for

Model MD-11 series airplanes), both dated November 1, 1993, that

describe procedures for installation of retainers and supports at the

lateral control mixer bracket on the center of the wing rear spar of

the airplane. This installation will minimize the possibility for

uncommanded extension of the spoiler in the event of a bracket failure

or separation from the airplane structure.

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 installation of retainers and supports at the

lateral control mixer bracket on the center of the wing rear spar of

the airplane. The actions would be required to be accomplished in

accordance with the applicable service bulletin described previously.

There are approximately 427 Model DC-10-10, -15, -30, and -40

series airplanes and KC-10A (military) airplanes of the affected design

in the worldwide fleet. The FAA estimates that 241 airplanes of U.S.

registry would be affected by this proposed AD, that it would take

approximately 3 work hours per airplane to accomplish the proposed

actions, and that the average labor rate is $55 per work hour. Required

parts would cost approximately $6,497 per airplane. Based on these

figures, the total cost impact of the proposed AD on U.S. operators of

DC-10 series airplanes is estimated to be $1,605,542 or $6,662 per

airplane.

There are approximately 114 Model MD-11 series airplanes of the

affected design in the worldwide fleet. The FAA estimates that 46

airplanes of U.S. registry would be affected by this proposed AD, that

it would take approximately 3 work hours per airplane to accomplish the

proposed actions, and that the average labor rate is $55 per work hour.

Required parts would cost approximately $6,497 per airplane. Based on

these figures, the total cost impact of the proposed AD on U.S.

operators of Model MD-11 series airplanes is estimated to be $306,452,

or $6,662 per airplane.

The total 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 regulations proposed herein would not have substantial direct

effects 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, in

accordance with Executive Order 12612, it is determined that this

proposal would not have sufficient federalism implications to warrant

the preparation of a Federalism Assessment.

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 14

CFR part 39 of the Federal Aviation Regulations as follows:

PART 39--AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C.

106(g); and 14 CFR 11.89.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding the following new

airworthiness directive:

McDonnell Douglas: Docket 94-NM-26-AD.

Applicability: Model DC-10-10, -15, -30, and -40 series

airplanes and KC-10A (military) airplanes, as listed in McDonnell

Douglas DC-10 Service Bulletin 27-222, dated November 1, 1993; and

Model MD-11 series airplanes, as listed in McDonnell Douglas MD-11

Service Bulletin 27-34, dated November 1, 1993; certificated in any

category.

Compliance: Required as indicated, unless accomplished

previously.

To prevent inadvertent asymmetric deployment of the spoiler,

which may lead to reduced controllability of the airplane,

accomplish the following:

(a) Within 12 months after the effective date of this AD,

install retainers and supports at the lateral control right- and

left-hand mixer bracket on the center of the wing rear spar of the

airplane in accordance with McDonnell Douglas DC-10 Service Bulletin

27-222, dated November 1, 1993 [for Model DC-10-10, -15, -30, and -

40 series airplanes and KC-10A (military) airplanes]; or McDonnell

Douglas MD-11 Service Bulletin 27-34, dated November 1, 1993 (for

Model MD-11 series airplanes); as applicable.

(b) An alternative method of compliance or adjustment of the

compliance time that provides an acceptable level of safety may be

used if approved by the Manager, Los Angeles Aircraft Certification

Office (ACO), FAA, Transport Airplane Directorate. Operators shall

submit their requests through an appropriate FAA Principal

Maintenance Inspector, who may add comments and then send it to the

Manager, Los Angeles ACO.

Note: Information concerning the existence of approved

alternative methods of compliance with this AD, if any, may be

obtained from the Los Angeles ACO.

(c) Special flight permits may be issued in accordance with

Federal Aviation Regulations (FAR) 21.197 and 21.199 to operate the

airplane to a location where the requirements of this AD can be

accomplished.

Issued in Renton, Washington, on June 1, 1994.

Darrell M. Pederson,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 94-13755 Filed 6-6-94; 8:45 am]

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