AD 93-24-51 SUPERSEDED

This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) T93-24-51 that was sent previously to all known U.S. owners and operators of all Airbus Model A310 and A300-600 series airplanes by individual telegrams. This AD requires repetitive operational tests of feel and limitation computers (FLC) 1 and 2. This amendment is prompted by a report that the pitch control on a Model A300-600 series airplane operated with stiffness. The actions specified by this AD are intended to prevent stiff operation of the pitch control and undetected loss of rudder travel limitation function.

Final rule; request for comments.

93-24-51 AIRBUS INDUSTRIE: Amendment 39-8783. Docket 93-NM-208-AD.

Applicability: All Airbus Model A310 and A300-600 series airplanes, certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent stiff operation of the pitch control and undetected loss of rudder travel limitation function, which may adversely affect controllability of the airplane, accomplish the following:

(a) Within 7 days after the effective date of this AD, perform an operational test to verify proper operation of feel and limitation computers (FLC) 1 and 2 in accordance with Airbus Industrie All Operator Telex 27-14, dated November 2, 1993. Thereafter repeat this test at intervals not to exceed 7 days.

(b) If any FLC fails the test, prior to further flight, replace with a new or serviceable FLC, or repair the FLC in accordance with a method approved by the Manager, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate.(c) As of the effective date of this AD, no airplane shall be operated with an inoperative pitch feel system or inoperative pitch feel fault lights.

(d) 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, Standardization Branch, ANM-113. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Standardization Branch, ANM-113.

NOTE: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Standardization Branch, ANM-113.

(e) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished.

(f) The test shall be done in accordance with Airbus Industrie All Operator Telex 27-14, dated November 2, 1993. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies may be obtained from Airbus Industrie, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

(g) This amendment becomes effective on January 20, 1994, to all persons except those persons to whom it was made immediately effective by telegraphic AD T93-24-51, issued December 1, 1993, which contained the requirements of this amendment.

On December 1, 1993, the FAA issued telegraphic airworthiness directive (AD) T93-24-51, which is applicable to all Airbus Model A310 and A300-600 series airplanes. That action was prompted by a report from an operator that the pitch control on a Model A300-600 series airplane operated with stiffness. Investigation into the cause of this stiffness revealed that the feel and limitation computer (FLC) failed and caused stiff operation of the pitch control. This condition, if not corrected, could result in stiff operation of the pitch control and undetected loss of rudder travel limitation function, which may adversely affect controllability of the airplane.

Airbus Industrie has installed these computers on all Model A310 and A300-600 series airplanes. Each airplane has two FLC's, designated FLC 1 and FLC 2. The FLC and the pitch feel fault lights are integral components of the pitch feel system. (The pitch feel fault lights indicate a failure of the FLC.)

Currently, these airplanes are allowed to operate with one inoperative pitch feel system. If the airplane is operated with one inoperative pitch feel system, failure of the other FLC could result in stiff operation of the pitch control and undetected loss of rudder travel limitation function. This failure could also allow excessive elevator movement, which could expose the airplane structure to excessive air loads.

Airbus Industrie has issued All Operator Telex (AOT) 27-14, dated November 2, 1993, applicable to all Airbus Model A310 and A300-600 series airplanes, that describes procedures for performing repetitive operational tests to verify proper operation of FLC's 1 and 2. The Direction G n rale de l'Aviation Civile (DGAC), which is the airworthiness authority for France, classified this AOT as mandatory and issued French telegraphic airworthiness directive 93-202-153(b), dated November 2, 1993, in order to assure the continued airworthiness of these airplanes in France.

This airplane model is manufactured in France and is type certificated for operation in the United States under the provisions of Section 21.29 of the Federal Aviation Regulations and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, the DGAC has kept the FAA informed of the situation described above. The FAA has examined the findings of the DGAC, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States.

Since the unsafe condition described is likely to exist or develop on other airplanes of the same type design registered in the United States, the FAA issued Telegraphic AD T93-24-51 to require repetitive operational tests to verify proper operation of FLC's 1 and 2. The actions are required to be accomplished in accordance with the AOT previously described. Any FLC that fails the operationaltest is required to be repaired or replaced in accordance with a method approved by the FAA.

The AD also prohibits operation of any airplane with an inoperative pitch feel system or inoperative pitch feel fault lights.

Since it was found that immediate corrective action was required, notice and opportunity for prior public comment thereon were impracticable and contrary to the public interest, and good cause existed to make the AD effective immediately by individual telegrams issued on December 1, 1993, to all known U.S. owners and operators of all Airbus Model A310 and A300-600 series airplanes. These conditions still exist, and the AD is hereby published in the Federal Register as an amendment to Section 39.13 of part 39 of the Federal Aviation Regulations (FAR) to make it effective as to all persons.

This is considered to be interim action. The manufacturer has advised that it currently is developing a modification that will positively address the unsafe condition addressed by this AD. Once this modification is developed, approved, and available, the FAA may consider additional rulemaking.

Comments Invited

Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this 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 under the caption "ADDRESSES." All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the 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 that summarizes each FAA-public contact concerned with the substance of this AD 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 93-NM-208-AD." The postcard will be date stamped and returned to the commenter.

The regulations adopted herein will 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 thevarious levels of government. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and is not a "significant regulatory action" under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES."

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.

Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends 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.

39.13 - [Amended]
2. Section 39.13 is amended by adding the following new airworthiness directive:

Submit comments in triplicate to the Federal Aviation Administration (FAA),
Transport Airplane Directorate, ANM-103, Attention: Rules Docket No. 93-NM-208-AD, 1601 Lind
Avenue, SW., Renton, Washington 98055-4056.
The applicable service information may be obtained from Airbus Industrie, 1 Rond Point
Maurice Bellonte, 31707 Blagnac Cedex, France. This information may be examined at the FAA,
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the
Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

Stephen Slotte, Aerospace Engineer, Standardization
Branch, ANM-113, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton,
Washington 98055-4056; telephone (206) 227-2797; fax (206) 227-1320.