Satellite Navigation for Helicopters

The Department of Defence of the United States is in the process of implementing a satellite‐based navigation system called Navstar GPS (Global Positioning System). This system will have 24 satellites orbiting in three different orbits, with 8 satellites in each. Full implementation is planned for the mid to late 1980s. Partial use of the system should be possible commencing in the early 1980s. GPS can provide many unique features of particular benefit to helicopters, such as highly accurate airborne area navigation (RNAV) capability; accurate approach and landing guidance solely by reference to the airborne RNAV system; ability to function on a worldwide basis without the need for ground based navigation aids; unlimited capacity. Numerous benefits in addition to highly accurate navigation will accrue from civil application of GPS, including capability for automatic position reporting and air‐to‐air separation assurance. Cost benefits make application of GPS to civil aircraft in general, and particularly helicopters, highly attractive.