Ring Sight™ LC-40-100-NVG-GSO is a solid glass reflex collimator sight with integral zeroing. It enables a helicopter gunner to aim at both ground and air targets by day and night with Night Vision Goggles (NVG). For low light and in the dark the graticule is lit by an in-built LED array always in place. The LED array is powered by batteries which can be lithium thionyl chloride (giving an excelent temperature range) or others: the brightness is adjusted by the gunner to suit the conditions. This means that low ambient light can be enhanced when needed and that NVG can be used without affecting their control. The LC-40-100-NVG-RN-DTC is the latest design with improved switches to be used on 20 and 30 mm naval cannons.
One advantage of the Ring Sight is its large aperture, 40 x 30 mm, making it the choice for pintle mounted gun where the firer wants the maximum eye freedom as he moves around the pintle, so the gunner does not have to position his eye precisely (up down, sideways and in and out) unlike conventional optical day and night sights which have limited eye freedom in all these directions.
The zeroing system is of a kinematic design, the screws being turned with a 13 mm spanner with approximately half mil clicks. The screws and nuts are manufactured in A4 stainless steel. The range of adjustments are: Horizontal 50 mils. Vertical 320 mils.
The sights are used by various countries on a variety of weapons. The sights are also capable of being fitted with Laser Illuminators and Range Finders. The picture above shows the sight with an illuminator the ILL/SIM/40 fitted to the M134. This sight is also used by GIAT on their 20 & 30mm cannons. Its 1 x magnification makes target acquisition and engagement easy, especially from a boat or ship moving with the waves.
Fig 2 shows the sight fitted to the M3M this time with an Illuminator Range Finder (LRF/P/50) The Range Finder was a new concept and in this configuration was used with great success during the Iraq conflict.
If air targets are to be engaged the graticule has radial lines to assist the gunner in choosing a suitable point of aim as shown in Fig 3. Graticule patterns can be provided to suit the expected engagements and the ballistics for the particular gun. The elevation and lead available on the graticule plate are more than adequate for the ranges and crossing speeds that can be used by the gunner. As the graticule plate is built in production, the pattern must be agreed for any order .