An electronic lateral acceleration indicator is provided that gives improved visual performance over previous electronic indicators. In a first embodiment, the lateral acceleration indicator includes a fine tuning element and a high level lateral acceleration element. The fine tuning element provides a precise reading of low level lateral acceleration. This allows a pilot to make small corrections to eliminate small amounts of lateral acceleration. The high level lateral acceleration element provides a strong visual indication when relatively high lateral acceleration is present. The strong visual indication provided by the high level lateral acceleration element increases the probability that the pilot will be made aware of the lateral acceleration. Thus, the lateral acceleration indicator of the present invention provides both fine tuning capability and a strong visual warning of large lateral acceleration to the pilot. In a second embodiment, the lateral acceleration indicator includes a lateral acceleration element that expands as lateral acceleration increases. This allows the pilot to quickly determine if lateral acceleration is occurring. Additionally, the rate of expansion in the lateral acceleration element relative to the increase in lateral mistrim can be tailored to provide improved visual scaling to the pilot.

A method for landing an aircraft includes determining the aircraft's deviation from its approach path so as to define a first point of the aircraft's heading. A first straight line passing through the first point and through a second point defining the ground orientation of the approach path is displayed, by a head-up display, on a horizon line with a heading scale. The first straight line represents a ground plot of the approach path. A first assistance gate is displayed such that the first straight line passes through the first assistance gate when the aircraft is aligned on the approach path. A second straight line, parallel with the horizon line and passing through the first point, is displayed and represents a plot on the ground of the origin of the approach path. A second assistance gate is displayed under the horizon line and represents the slope of the approach path.

A meniscus combiner for a head up display (HUD) system. The meniscus combiner includes a meniscus lens; a multi-layer dichroic coating formed on a first surface of the meniscus lens; and, an anti-reflection coating formed on a second, opposite surface of the meniscus lens. The meniscus combiner preferably utilizes a non-symmetric aspheric meniscus lens which simplifies the optical system of the image source (overhead or in-dash unit) minimizing aberrations and minimizing costs. The meniscus combiner may be fabricated utilizing a number of lens sections which may be bonded together and blended. Use of multiple lens sections provides the ability to easily optimize the lens design. Alternatively, the meniscus combiner can be fabricated from a single lens.

The pilot or crew of an aircraft is alerted to the danger presented by wires in the vicinity of the aircraft by a flight instrument which includes a plurality of wire detected display elements, advantageously arranged as bars on the face of the flight instrument, and which display elements are color coded according to the level of danger presented to the aircraft by the detected wires.

A head up display system for a vehicle that includes a compact image source for projecting an image. The compact image source may be foldable up toward or into a cockpit ceiling of the vehicle, be positioned within a dashboard of the vehicle, or located at another suitable position. A combiner reflects the projected image with optical power toward an observer for observation. The combiner is positioned so that the observer, in a line of sight, may see a visual exterior view of an outside scene through the combiner and the projected image in the combiner. In a preferred embodiment, the image source includes an illumination system that includes a high power light emitting diode (LED) array assembly. A Fresnel lens array is operatively associated with the LED array assembly for receiving light produced by the LED and providing a nearly collimated light output. A spatial light modulator receives the nearly collimated light output. The preferred combiner is a meniscus combiner that includes a meniscus lens; a multi-layer dichroic coating formed on a first surface of the meniscus lens; and, an anti-reflection coating formed on a second, opposite surface of the meniscus lens. The meniscus combiner preferably utilizes a non-symmetric aspheric meniscus lens.