This International Standard specifies the structure, performance, inspection and testing of heading control systems to be installed on board craft operating under the following conditions: a) speed exceeding 30 kn and up to 70 kn; b) maximum rate of turn 20°/s; c) normal range of operation between 70°N and 70°S should, as required by chapter 13 of the HSC Code, comply with the minimum performance requirements specified in these standards. This International Standard applies to the heading control systems which enable a craft to keep a preset heading with minimum operation of the craft's steering gear, within limits related to the craft's manoeuvrability in conjunction with their sources of heading information. This International Standard assumes the use of a conventional arrangement. Where other arrangements are provided, the requirements of this standard should apply insofar as they are applicable, and appropriate justification provided where deviation from the requirements is necessary. The heading control systems should, within a speed range of up to 30 knots, comply with resolution A.342(IX), and within a speed range of 30 knots to 70 knots should comply with the requirements of this resolution. NOTE 1 All requirements that are extracted from the recommendations of IMO Resolutions [Resolution A.822(19) on performance standards for automatic steering aids for high-speed craft, A.694(17) and A.342(IX)] are printed in italics. NOTE 2 The heading control system was previously called "automatic steering aids (automatic pilot)". NOTE 3 Resolution A.342(IX) represents Resolution A.342(IX) as amended by MSC.64(67), Annex 3.