Stewart Penney/PLYMOUTH
British Aerospace Systems and Equipment (BASE) is preparing for flight trials of a helicopter version of its Terprom digital terrain avoidance and navigation system.
Terprom - which recently added US Air Force Boeing C-17 airlifters to its list of applications - will be evaluated on a British Army GKN Westland Lynx next month. Navigation and terrain avoidance capabilities will be on trial.
BASE marketing director-navigation Paul Davies says the system will be embedded in a Honeywell 764G inertial navigation system and linked to a Smiths Industries flat panel colour display and the helicopter's audio system. The set- up removes the need to integrate Terprom with the Lynx. If the trials are successful, BASE aims to undertake proper integration.
Davies says BASE has adapted Terprom to cope with the slow ground speed of helicopters and with hovering: it can handle 20min of hover without requiring a navigation update.
Commands to the pilot have to be less prescriptive than for fast jets, which will always pull up to avoid terrain, rather than stop or skirt around an obstacle.
Helicopter Terprom - a software-based product - will be integrated with a monocular sight or a helmet-mounted display. An audio-based system is being considered.
Helicopter Terprom, says Davies, provides an "intuitive feel" of surrounding terrain by displaying chevrons indicating dangerous terrain. The chevrons become bigger as the obstacle gets nearer and change into crosses once the helicopter is too close.
Monocular displays are becoming cheaper, says Davies. Systems could be fitted to special forces and transport helicopters, which operate nap-of-the-earth flight profiles, as well as combat machines such as the Boeing AH-64 Apache.
Future developments could integrate Terprom with laser wire detectors which pick out obstacles such as electricity transmission cables that do not normally appear in terrain databases.
Source: Flight International
