# Airworthiness Directives; Short Brothers Model SD3-60 Series Airplanes > Briefs, arguments, decisions, and more. URL: https://www.frixlaw.com/law-library/documents/fr%3A94-20159 ## Record - **Collection:** Federal Register - **Document type:** Uncategorized Document - **Published:** August 17, 1994 ## Text DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. 94-NM-96-AD] Airworthiness Directives; Short Brothers Model SD3-60 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 Short Brothers Model SD3- 60 series airplanes. This proposal would require installation of a certain time delay relay and associated wiring into a circuit of the rudder gust lock. This proposal is prompted by reports of inadvertent engagements of the rudder gust lock on in-service Model SD3-60 series airplanes. The actions specified by the proposed AD are intended to prevent premature locking of the rudder gust lock, which could result in reduced controllability of the airplane in flight and during landing roll. DATES: Comments must be received by September 26, 1994. ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-103, Attention: Rules Docket No. 94-NM-96-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 Short Brothers, PLC, 2011 Crystal Drive, Suite 713, Arlington, Virginia 22202-3719. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. FOR FURTHER INFORMATION CONTACT: Sam Grober, Aerospace Engineer, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 227-1187; fax (206) 227-1320. 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-96-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-96-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Discussion The Civil Aviation Authority (CAA), which is the airworthiness authority for United Kingdom, recently notified the FAA that an unsafe condition may exist on certain Short Brothers Model SD3-60 series airplanes. The CAA advises that it has received reports of inadvertent engagements of the rudder gust lock on in-service Model SD3-60 series airplanes. Investigation revealed that these inadvertent engagements were caused by premature locking of the rudder gust lock system. Premature locking of the rudder gust lock, if not corrected, could result in reduced controllability of the airplane in flight and during landing roll. Short Brothers has issued Shorts Service Bulletin SD360-27-23, Revision 1, dated April 15, 1994, which describes procedures for installation of a 10-second time delay relay, having part number TDD- AYOF-1002, and associated wiring into a circuit of the rudder gust lock. Such an installation safeguards against inadvertent locking of the rudder gust lock until the airplane can reach a ground speed at which the nose wheel steering can be used. The CAA classified this service bulletin as mandatory and issued CAA Airworthiness Directive 013-02-94, dated March 24, 1994, in order to assure the continued airworthiness of these airplanes in the United Kingdom. This airplane model is manufactured in the United Kingdom 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, the CAA has kept the FAA informed of the situation described above. The FAA has examined the findings of the CAA, 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 installation of a certain 10-second time delay relay and associated wiring into a circuit of the rudder gust lock. The actions would be required to be accomplished in accordance with the service bulletin described previously. The FAA estimates that 88 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 29 work hours per airplane to accomplish the proposed actions, and that the average labor rate is $55 per work hour. Required parts would be supplied by the manufacturer at no cost to the operators. Based on these figures, the total cost impact of the proposed AD on U.S. operators is estimated to be $140,360, or $1,595 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: Short Brothers, PLC: Docket 94-NM-96-AD Applicability: Model SD3-60 series airplanes on which Modification 8112 (reference Shorts Service Bulletin SD360-27-16) has been installed, certificated in any category. Compliance: Required as indicated, unless accomplished previously. - To prevent reduced controllability of the airplane in flight and during landing roll, accomplish the following: (a) Within 90 days after the effective date of this AD, install a 10-second time delay relay, having part number TDD-AYOF-1002, and associated wiring into a circuit of the rudder gust lock, in accordance with Shorts Service Bulletin SD360-27-23, Revision 1, dated April 15, 1994. (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, 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. (c) 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 August 11, 1994. Darrell M. Pederson, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 94-20159 Filed 8-16-94; 8:45 am] BILLING CODE 4910-13-P --- Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A94-20159. Public record. Not legal advice.