Optical Landing System

As an Optical Landing System, an optical system to support the landing approach is called on aircraft carriers and military airfields. The system is also known by the nickname Meatball (German meat ball).

Development

The introduction of the approaching aircraft on aircraft carriers was originally taken from the landing signal officers, were teaching the machine by means of gestures to the correct Landeweg. When, after the Second World War progressed the development of the aircraft carrier and the machines became faster and faster, the previous system was too vague and too slow. Therefore A British officer developed in the early 1950s, a system based on mirrors optical system that had the pilot of the aircraft approaching the proper landing angle. The Optical Landing System was invented as a Mirror Landing Aid by British Lieutenant Commander HCN Goodhart ( Royal Navy ).

Design and function

Mirror -based system

A strong spotlight dimmed to a cross-shaped slit irradiated from a distance horizontally a mirror of sufficient size, which is inclined at half the angle of the displayed trace path from the vertical. To each side of the mirror each is a horizontal line from rows of green lights. A pilot, in sufficient detail looks at gliding in for a landing - as if through a window - in the mirror of the virtual image of cross of light aperture. The sighted position of the cross in the gap of the two green lines provides the pilot the position of the aircraft with respect to the desired glide path is: Is about the pilot too high and too far to the right appear the cross, because even at a distance " behind the window ", higher than that of the gap center line and on the right of the lines. Finally, the pilot must, however, more closely geared to the slopes next to the mirror back and Fillet the glide angle in the direction of horizontal position. The mirror can be adjusted for different angle of approach and somewhat convex at its edges for ease of "capturing" the flier (only ). The mirror system is suspended gyroscopically to compensate for the rolling and pitching of the ship.

Lens -based system

Since the mirror-based system proved to be unreliable in some situations, tested the United States Navy in the 1960s, a system in which Fresnel projection of light took over. Opposite the mirror system here was the change that the pilot also saw a red light at an extremely low approach, which prompts him to cancel.