GULFSTREAM PLANS to demonstrate an enhanced-vision system (EVS) on a Gulfstream IV business jet later this year, to meet customer demand for a reduced-visibility landing capability. Flights will involve a GIV-SP demonstrator equipped with a Mitsubishi infra-red (IR) sensor, imagery from which will be projected on to a Honeywell/GEC head-up display (HUD).
The US manufacturer wants to demonstrate the EVS-equipped GIV at the Farnborough air show in September, which HUD programme-manager Bob Morris admits to be a "tight schedule". Flight-testing of the HUD is already under way, aiming for Category II certification in the third quarter of 1996 on the GIV, with GV approval following in 1997.
Morris says that Gulfstream customers want lower minima at Cat I-equipped airfields, to avoid being limited to Cat III-capable airports when visibility is reduced. In particular, those who will operate the long-range GV are concerned by the greater potential for weather to deteriorate at the destination airport during longer flights.
"Operators do not want to be circling their destination airport while their competitors - the airlines - are getting in," Morris says.
Gulfstream is evaluating EVS sensors, including IR and both passive and active millimetre-wave (MMW). In the near term, the company is likely to use an existing 3-5µm-wavelength IR sensor modified to detect runway lights, which lie in the 1-2µm waveband, he says.
Morris says that passive-MMW radiometry looks promising, but is not advancing "...as quickly as hoped". Active-MMW radar, meanwhile, is expected to available "in the next couple of years". GIV demonstration flights will concentrate on data collection, with sensor-certification test-flying to be conducted using a lower-cost aircraft, he says.
The company is now leading EVS development, since airline programmes have slowed or stopped altogether. "It looks like Gulfstream is in pole position, although we would prefer to be second," Morris admits.
Source: Flight International
