Digital Terrain Systems for Helicopters

This paper discusses how the application of Digital Terrain Systems to helicopters can lead to significant improvements in pilot situation awareness, survivability and mission effectiveness. The GEC Avionics Total Terrain Avionics (TTA) concept is introduced and specific elements are described in detail. The terrain database required to support the various TTA functions is discussed in terms of the data requirements and the storage technology. Most of the TTA functions require a precision navigation input and a description is given of how this is achieved. A tactical routing function calculates the optimum route for the aircraft taking into account the threat situation, terrain screening, fuel and time. A weapon aiming function calculates targeting information using the precision navigation and terrain data. The enhanced situation awareness is achieved through a number of advanced display options which are described. Finally, some recent flight testing of TTA concepts is discussed.