GENERAL DESCRIPTION

The unit is battery powered and can be controlled either manually or

by radio control. It emits infra-red light at a fixed intensity so providing

complete compatibility with generation 2 and 3 Night Vision

Goggles (NVG).

CONSTRUCTION & FINISH

The projector base is manufactured from a honeycomb sandwich,

composite material which provides a flat, lightweight but extremely rigid

platform upon which the optical system is mounted. The optical system

comprises two parabolic reflectors, two beam splitters, two doublet lens

assemblies and two infra-red absorption filters. The battery, inclinometer

and spirit level are also mounted on the projector base. Three threaded

adjusting legs, fitted with coil springs, support the projector base which

is protected from the elements by a weatherproof enclosure which is

secured in position by the attitude adjusting knobs. The enclosure

incorporates viewing windows for both the inclinometer and the spirit

level. A hinged panel gives access to the inclinometer to enable the

operator to set the desired approach angle. A window in the forward face

of the unit protects the optical system from stone damage that may be

caused by jet efflux. The radio antenna, control switches and battery

charging connector are mounted on the enclosure.

All fittings are fully corrosion protected.

PHOTOMETRIC PERFORMANCE

The NVG-PAPI is a two lamp unit which produces a single intensity

infra-red signal, half of which is steady light and half of which is occulting

light. As it is not possible to see colour in the infra-red spectrum the usual

red signal seen in PAPI systems is replaced by the occulting signal.

No visual spectrum light is emitted from the unit. A full four unit PAPI

system is provided with MOSKIT and the information presented to the

pilot is as follows:

4 x Steady Lights - WELL ABOVE THE GLIDE SLOPE

3 x Steady 1 x Flashing - SLIGHTLY ABOVE

2 x Steady 2 x Flashing - ON SLOPE

3 x Flashing 1 x Steady - SLIGHTLY BELOW

4 x Flashing - WELL BELOW THE GLIDE SLOPE

Approach angles of between 2 and 8 can be achieved and the unit is

accurate to within one minute of arc.

POWER SUPPLY & ENDURANCE

Power is supplied from a single 12v 7.0Ah rechargeable, maintenance free,

sealed lead acid battery (SLAB) giving eight hours continuous performance.

The battery is fixed in the unit and need only be taken out when

replacement is required. Battery charging is accomplished via a sealed

battery charging connector.