[Federal Register Volume 59, Number 182 (Wednesday, September 21, 1994)] [Unknown Section] [Page 0] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 94-23327] [[Page Unknown]] [Federal Register: September 21, 1994] VOL. 59, NO. 182 Wednesday, September 21, 1994 DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. 94-NM-127-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- 100 and -300 series airplanes. This proposal would require an inspection to verify the integrity of the shield grounds for the cable harness of the electronic engine control (EEC), and correction of any discrepancy. This proposal also would require measurement of the electrical resistance of certain shield grounds, and repair, if necessary. This proposal is prompted by a report of an engine flameout after a lightning strike, due to several shields for the cable harness of the EEC not being properly grounded to the airframe. The actions specified by the proposed AD are intended to prevent engine flameout due to insufficient protection of the EEC. DATES: Comments must be received by October 31, 1994. ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-103, Attention: Rules Docket No. 94-NM-127-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., Bombardier Regional Aircraft Division, Garratt Boulevard, Downsview, Ontario, Canada M3K 1Y5. 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: Richard Fiesel, Aerospace Engineer, Propulsion Branch, ANE-174, FAA, Engine and Propeller Directorate, New York Aircraft Certification Office, 181 South Franklin Avenue, Room 202, Valley Stream, New York 11581; telephone (516) 791-7421; 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-127-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-127-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Discussion On April 25, 1989, the FAA issued AD 85-14-51 R2, amendment 39-6207 (54 FR 19875, May 9, 1989), which is applicable to certain de Havilland Model DHC-8-100 series airplanes. That AD requires revising the Limitations Section of the FAA-approved Airplane Flight Manual (AFM) to prohibit takeoff, landing, and climb in the vicinity of lightning or thunderstorms; and to require continuous ignition operation during takeoffs, takeoff climb to 1500 feet above ground level, final approach, and landing within 5 nautical miles of lightning and thunderstorms. That AD also requires the installation of four modifications designed to protect the electronic engine control (EEC) from the effects of lightning strike, which, when accomplished, terminates the requirements of that AD and allows for the removal of the AFM limitations. Since issuance of that AD, Transport Canada Aviation, which is the airworthiness authority for Canada, has advised the FAA of a report of an engine flameout after a lightning strike on a Model DHC-8 series airplane. Modifications required by AD 85-14-51 R2 had been accomplished on that airplane. Investigation revealed that the engine flameout occurred because several shields for the cable harness of the EEC were not properly grounded to the airframe. This condition, if not corrected, could result in insufficient protection of the EEC and may lead to an engine flameout following a lightning strike. Bombardier has issued Service Bulletins S.B. 8-73-18 (for Model DHC-8-100 series airplanes) and S.B. 8-73-19 (for Model DHC-8-300 series airplanes), both dated April 29, 1994, which describe procedures for a visual inspection to verify the integrity of the shield grounds for the cable harness of the EEC, and correction of any discrepancy. The service bulletins also describe procedures for measurement of the electrical resistance of certain shield grounds, and repair, if necessary. The repair procedures consist of ensuring that the metal overbraid (which provides lightning protection for the EEC cable harness) is electrically bonded to the connector and the electrical receptacles are electrically bonded to the airframe. Transport Canada Aviation classified these service bulletins as mandatory and issued Canadian Airworthiness Directive CF-94-09, dated May 5, 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 examined the findings of Transport Canada Aviation, 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 visual inspection to verify the integrity of the shield grounds for the cable harness of the EEC, and correction of any discrepancy. This AD also would require measurement of the electrical resistance of certain shield grounds, and repair, if necessary. The actions would be required to be accomplished in accordance with the service bulletins described previously. The FAA estimates that 141 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 16 work hours per airplane to accomplish the proposed actions, and that the average labor rate is $55 per work hour. Based on these figures, the total cost impact of the proposed AD on U.S. operators is estimated to be $124,080, or $880 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 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.: 94-NM-127-AD. Applicability: Model DHC-8-102, -103, and -106 series airplanes, serial numbers 3 through 369 inclusive; and Model DHC-8-301, -311, and -314 series airplanes, serial numbers 100 through 370 inclusive; certificated in any category. Compliance: Required as indicated, unless accomplished previously. To prevent engine flameout following a lightning strike, accomplish the following: (a) Within 45 days after the effective date of this AD, perform a visual inspection of the mounting clamps and ``breakout junctions'' in the metal overbraid to verify the integrity of the shield grounds for the cable harness of the electronic engine control (EEC), in accordance with de Havilland Service Bulletin S.B. 8-73-18 (for Model DHC-8-100 series airplanes), or S.B. 8-73-19 (for Model DHC-8-300 series airplanes), both dated April 29, 1994, as applicable. If any discrepancy is found, prior to further flight, correct the discrepancy in accordance with the applicable service bulletin. (b) Within 45 days after the effective date of this AD, perform an electrical resistance measurement of Class A and Class B shield grounds in accordance with de Havilland Service Bulletin S.B. 8-73- 18 (for Model DHC-8-100 series airplanes), or S.B. 8-73-19 (for Model DHC-8-300 series airplanes), both dated April 29, 1994, as applicable. (1) For Class A shield grounds: If the electrical resistance exceeds the value specified in the service bulletin, within 50 flight hours after performing the resistance measurement repair in accordance with the applicable service bulletin. (2) For Class B shield grounds: If the electrical resistance exceeds the value specified in the service bulletin, within 180 days after performing the resistance measurement repair in accordance with the applicable service bulletin. (c) For Model DHC-8-102, -103, and -106 series airplanes on which an interim shield ground is installed in accordance with paragraphs 19 and 93 of the Accomplishment Instructions of de Havilland Service Bulletin S.B. 8-73-18, dated April 29, 1994: Within one year after the effective date of this AD, restore the airplane to the Post-Modification 8/0772 configuration in accordance with paragraph 161 of the Accomplishment Instructions of that service bulletin. (d) For Model DHC-8-301, -311, and -314 series airplanes on which an interim shield ground is installed in accordance with paragraphs 19 and 112 of the Accomplishment Instructions of de Havilland Service Bulletin S.B. 8-73-19, dated April 29, 1994: Within one year after the effective date of this AD, restore the airplane to the Post-Modification 8/0772 configuration in accordance with paragraph 200 of the Accomplishment Instructions of that service bulletin. (e) 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. (f) 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 15, 1994. Donald L. Riggin, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 94-23327 Filed 9-20-94; 8:45 am] BILLING CODE 4910-13-U