[Federal Register Volume 59, Number 186 (Tuesday, September 27, 1994)] [Unknown Section] [Page 0] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 94-23813] [[Page Unknown]] [Federal Register: September 27, 1994] ----------------------------------------------------------------------- DEPARTMENT OF TRANSPORTATION 14 CFR Part 39 [Docket No. 94-NM-89-AD] Airworthiness Directives; de Havilland Model DHC-8-100 and -300 Series 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 de Havilland Model DHC-8 series airplanes. This proposal would require inspection to detect corrosion on areas of the airplane structure where black film thermal insulation is used, and repair, if necessary; and replacement of black insulation blankets with certain aluminized (silver) insulation. This proposal is prompted by reports of corrosion forming on areas of the airplane structure where the black film covers the thermal insulation blankets. The actions specified by the proposed AD are intended to prevent degradation of the structural capability of the airplane fuselage and sudden loss of cabin pressure due to corrosion of the airplane fuselage structure. DATES: Comments must be received by November 21, 1994. ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-103, Attention: Rules Docket No. 94-NM-89-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal holidays. The service information referenced in the proposed rule may be obtained from Bombardier, Inc., Garratt Boulevard, Downsview, Ontario M3K 1Y5, Canada. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Engine and Propeller Directorate, New York Aircraft Certification Office, 181 South Franklin Avenue, Room 202, Valley Stream, New York. FOR FURTHER INFORMATION CONTACT: Jon Hjelm, Aerospace Engineer, Airframe Branch, ANE-172, FAA, Engine and Propeller Directorate, New York Aircraft Certification Office, 181 South Franklin Avenue, Room 202, Valley Stream, New York 11581; telephone (516) 791-6220; fax (516) 791-9024. 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-89-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-89-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Discussion Transport Canada Aviation, which is the airworthiness authority for Canada, recently notified the FAA that an unsafe condition may exist on certain de Havilland Model DHC-8-100 and -300 series airplanes. Transport Canada Aviation advises that there have been reports of corrosion forming on areas of the airplane structure where black Orcon film covers the thermal insulation blankets. Investigation revealed that the black Orcon film used to insulate the forward fuselage, passenger compartment, flight compartment, and ventilation ducts contains carbon. The cause of this corrosion has been attributed to the formation of condensation on any aluminum airplane structure when it is in contact with the carbon in the black Orcon film. Such corrosion, if not detected and corrected in a timely manner, could result in degradation of the strength of the airplane fuselage structure and could lead to sudden loss of cabin pressure. Bombardier, Inc. (formerly de Havilland) has issued Service Bulletins S.B. 8-25-89, Revision D; S.B. 8-25-90, Revision B; S.B. 8- 25-91, Revision C; S.B. 8-25-92, Revision D; and S. B. 8-25-93, Revision B; all dated January 19, 1994. These service bulletins describe procedures for one-time visual inspection to detect corrosion on areas of the airplane structure where black film thermal insulation is used, and repaired, if necessary. The service bulletins also describe procedures for replacement of black Orcon film insulation blankets with AN4C aluminized (silver) film thermal insulation blankets in various areas of the airplane structure. Transport Canada Aviation classified these service bulletins as mandatory and issued Canadian Airworthiness Directive CF-94-08, dated April 26, 1994, in order to assure the continued airworthiness of these airplanes in Canada. This airplane model is manufactured in Canada and is 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, Transport Canada Aviation has kept the FAA informed of the situation described above. The FAA has 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 an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design registered in the United States, the proposed AD would require a one-time visual inspection to detect corrosion on areas of the airplane structure where black film thermal insulation is used, and repaired, if necessary. This proposed AD also would require replacement of black Orcon film thermal insulation blankets with AN4C aluminized (silver) film insulation blankets. The actions would be required to be accomplished in accordance with the service bulletins described previously. The FAA estimates that 125 airplanes of U.S. registry would be affected by this proposed AD, that it would require approximately 650 work hours to accomplish the required actions, at an average labor charge of $55 per work hour. The FAA has been advised that the manufacturer plans to provide required parts and to accomplish the required modification at no expense to operators. Therefore, there is no cost impact on U.S. operators that is associated with this proposed rule with regard to labor charges or parts costs. The FAA does recognize, however, that while operators may incur administrative costs associated with compliance to this proposed rule, the one-year compliance time specified in paragraph (a) of this proposed AD should allow ample time for the proposed requirements to be accomplished coincidentally with scheduled major airplane inspection and maintenance activities, thereby minimizing the costs associated with special airplane scheduling. 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 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. Sec. 39.13 [Amended] 2. Section 39.13 is amended by adding the following new airworthiness directive: De Havilland, Inc.: Docket 94-NM-89-AD. -Applicability: Model DHC-8-100 and -300 series airplanes, variants and serial numbers specified in paragraph (a) of this AD, certificated in any category. -Compliance: Required as indicated, unless accomplished previously. To prevent degradation of the structural capability of the fuselage and sudden loss of cabin pressure, accomplish the following: (a) For airplanes listed in the following table: Within one year after the effective date of this AD, accomplish paragraphs (a)(1) and (a)(2) of this AD in accordance with the Bombardier Service Bulletins, all dated January 19, 1994, as listed in the table below, as applicable. ---------------------------------------------------------------------------------------------------------------- Service bulletin Revision DHC-8 models Airplane serial numbers number level ---------------------------------------------------------------------------------------------------------------- 101, 102, 103, and 106.............. 003 through 353 inclusive........... S.B. 8-25-89......... D 101, 102, 103, and 106.............. 003 through 380 inclusive........... S.B. 8-25-90......... B 101, 102, 103, 106, 301, 311, and 003 through 337 inclusive, 339, 341 S.B. 8-25-91......... C 314. through 347 inclusive, 349, 350, 351, 353, and 356. 301, 311, and 314 -................. 100 through 336 inclusive, 342, 350, S.B. 8-25-92-........ D and 356. 301, 311, and 314-.................. 100 through 381 inclusive........... S.B. 8-25-93......... B ---------------------------------------------------------------------------------------------------------------- (1) Perform a visual inspection to detect corrosion of the passenger compartment, flight compartment, forward fuselage, and air conditioning system. If any corrosion is found; prior to further flight, repair damage in accordance with the applicable service bulletin. (2) Replace the black Orcon film insulation blankets with AN4C aluminized (silver) film thermal insulation blankets in accordance with the applicable service bulletin. (b) As of one year after the effective date of this AD, no person shall install black Orcon film insulation, part number AN46B/ AN36B, on any airplane. (c) 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, New York Aircraft Certification Office (ACO), ANE-170, FAA, Engine and Propeller Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, New York ACO. -Note: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the New York ACO. (d) 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. Issued in Renton, Washington, on September 21, 1994. Darrell M. Pederson, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 94-23813 Filed 9-26-94; 8:45 am] BILLING CODE 4910-13-U