Three Channel Projection

With short throw lenses and the correct alignment, projected systems can produce an almost wrap round field of view. There are both advantages and disadvantages of projection. A darkened room or complete enclosure from the front of the cockpit windows to the screen itself is required. Projected systems can then take up considerable space in front of the simulator cab. Even with the use of short through lenses space becomes a consideration. The screen can be made from a continues curve, or more commonly x3 square (1:133) screens placed at respective angles to the projectors allowing for small image overlaps to give the impression of a continues image. With lower cost projectors, resolution and the lack of getting a true black can in some situations become a limitation. Low visibility operations or dusk/night these type of limitations are quite noticable where blacks are grey, and the runway lighting is not of sufficient resolution to give pin points of light. Depending on what type of training (or use) and level of training the simulator is planned for, when clear approach light patterns are a necessary requirement the only solution may be to use much higher resolution projectors. 

Three Channel TFT

Whilst the initial cost of the screens is high (no more than higher end video projectors) the TFT screens offer a easier way to set-up a three channel display. Resolution and true blacks can be maintained and there is no need for light traps or a dark environment. It is not possible to get a seamless transition from one image to another, but it is easy to add further channels. A lot of fixed based flight training devices that wish to employ visual systems are switching the the TFT method.

Collimated Display

The modern day projected collimated display offers the best solution for visual systems. These are able to achieve complete emersion and give depth perception. Most projected collimated display systems are cost prohibitive and generally not a requirement for any type of low level training.

We have decided to use the older type of collimated display which still gives a totally immersive visual with depth to the pilots. They use high resolution CRT monitors which reflect into the beam splitters / concave mirrors, this in turn reflects the greatly enlarged image back to the pilot. We are using a recently decommissioned full motion collimated display. It has two 21" monitor at 1280x1024 resolution which produces very high resolution images. The mirrors are 50 inches / 207cm across and fill the pilots forward field of view. Generally these systems are best used either at night or dusk but can also be used for daylight flying. They require very limited space in front of the simulator cab and the light traps are designed to fit against the forward flight deck windows.