AD 94-10-51

This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) T94-10-51 that was sent previously to all known U.S. owners and operators of certain Airbus Model A300, A300-600, and A310 series airplanes by individual telegrams. This AD requires a detailed visual inspection to detect cracks, delamination, or discoloration of the bus bar of certain aft fixed side cockpit windows; and deactivation of the window heating system and repetitive detailed visual inspections, or replacement of the window with a modified window, if necessary. This amendment is prompted by a report of fracture of a fixed cockpit window that led to electrical arcing in the bus bar area of the window heating system on a Model A300 series airplane. The actions specified by this AD are intended to prevent decompression of the fuselage during flight due to failure of a window.

Final rule; request for comments.

94-10-51 AIRBUS INDUSTRIE: Amendment 39-8931. Docket 94-NM-63-AD.

Applicability: Model A300, A300-600, and A310 series airplanes; as listed in Airbus Industrie All Operators Telex (AOT) 56-01, Revision 1, dated April 29, 1994; certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent decompression of the fuselage during flight, accomplish the following:

(a) Within 15 days after the effective date of this AD, perform a detailed visual inspection to detect cracks, delamination, or discoloration (black or brown burnt spots) of the bus bar of the aft fixed windows, in accordance with Airbus Industrie AOT 56-01, Revision 1, dated April 29, 1994.

(b) If any crack or delamination is found during the inspection required by paragraph (a) of this AD, prior to further flight, replace the affected window with a modified window, in accordance with Airbus Industrie AOT 56-01, Revision 1, dated April 29, 1994.

(c)If no cracks, delamination, or discoloration is found during the inspection required by paragraph (a) of this AD, accomplish either paragraph (c)(1) or (c)(2) of this AD in accordance with Airbus Industrie AOT 56-01, Revision 1, dated April 29, 1994.

(1) Within 7 days after accomplishing the inspection required by paragraph (a) of this AD, and thereafter at intervals not to exceed 7 days, repeat the inspection required by paragraph (a) of this AD; or

(2) Prior to further flight, deactivate the side window heating system in accordance with the AOT.

(d) If any discoloration is found during the inspections required by paragraph (a) or (c) of this AD, and that discoloration measures less than 10mm in diameter, accomplish paragraphs (d)(1), (d)(2), and (d)(3) of this AD in accordance with Airbus Industrie AOT 56-01, Revision 1, dated April 29, 1994.

(1) Prior to further flight, deactivate the side window heating system on the affected side, in accordance with the AOT.(2) Seven days after deactivating the window heating system, inspect the affected window to detect cracks or delamination formation around the discolored area, in accordance with the AOT.

(3) If any crack or delamination is found during the repeat inspection required by paragraph (d)(2) of this AD, prior to further flight, replace the window with a modified window, in accordance with the AOT.

(e) If any discoloration is found during the inspection required by paragraph (a) or (c) of this AD, and that discoloration measures 10mm or more in diameter, accomplish paragraphs (e)(1), (e)(2), and (e)(3) of this AD, in accordance with Airbus Industrie AOT 56-01, Revision 1, dated April 29, 1994.
(1) Prior to further flight, deactivate the side window heating system on the affected side, in accordance with the AOT.
(2) Thereafter, at daily intervals, inspect the affected window to detect cracks or delamination formation around the discoloration area, in accordance with theAOT.
(3) If any crack or delamination is found during the inspections required by paragraph (e)(2) of this AD, prior to further flight, replace the window with a modified window in accordance with the AOT.

(f) Replacement of the aft fixed side window in accordance with Airbus Industrie AOT 56-01, Revision 1, dated April 29, 1994, constitutes terminating action for the requirements of this AD.

(g) 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, 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, 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.(h) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.

(i) The inspections, deactivation, and replacement, shall be done in accordance with Airbus Industrie All Operators Telex (AOT) 56-01, Revision 1, dated April 29, 1994. 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.

(j) This amendment becomes effective on June 28, 1994, to all persons except those persons to whom it was made immediately effective by telegraphic AD T94-10-51, issued May 3, 1994, which contained the requirements of this amendment.

On May 3, 1994, the FAA issued telegraphic AD T94-10-51, which is applicable to certain Airbus Industrie Model A300, A300-600, and A310 series airplanes. That action was prompted by a report of fracture of a fixed cockpit window on the right-hand aft side of the cockpit of a Model A300 series airplane. Embrittlement of the fixed cockpit window and simultaneous rupture of the two main plies of the window have been attributed to electrical arcing in the bus bar area of the window heating system. This condition, if not corrected, could result in decompression of the fuselage during flight.

Since the subject windows installed on Model A300-600 and A310 series airplanes are similar in design to those on Model A300 series airplanes, the FAA has determined that these airplanes are also subject to the addressed unsafe condition.

Airbus Industrie has issued All Operators Telex (AOT) 56-01, Revision 1, dated April 29, 1994, that describes procedures for adetailed visual inspection to detect discoloration (black or brown burnt spots) of the bus bar of certain aft fixed side windows; and either deactivation of the window heating system coupled with repetitive detailed visual inspections, or replacement of the window with a modified window, if necessary. 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 N 94-104-160(B), dated April 26, 1994, in order to assure the continued airworthiness of these airplanes in France.

These airplane models are manufactured in France and are type certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) 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 hasexamined 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 T94-10-51 to require a detailed visual inspection to detect cracks, delamination, or discoloration (black or brown burnt spots) of the bus bar of certain aft fixed side windows; and either deactivation of the window heating system and repetitive detailed visual inspections, or replacement of the window with a modified window, if necessary. The actions are required to be accomplished in accordance with the AOT described previously.

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 May 3, 1994, to all known U.S. owners and operators of certain Airbus Model A300, A300-600, and A310 series airplanes. These conditions still exist, and the AD is hereby published in the Federal Register as an amendment to section 39.13 of the Federal Aviation Regulations (14 CFR 39.13) to make it effective as to all persons.
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 94-NM-63-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 the various 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 Policiesand 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 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. 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: