Abstract: A precision approach path indicator (PAPI) employs an LED light source with first and second arrays of LEDs or other efficient light sources, disposed one above the other and emitting their respective color lights along an optic axis to a collimating lens of focal length f. First and (optional) second aperture plates positioned along the optic axis, each being a respective frame with a cut-out defining a horizontally elongated aperture for light passing along the optic axis. Intermediate aperture plate(s) can be positioned between the first and second aperture plates. The first frame is positioned between the light source and the collimating lens at the focal distance f from the lens. The optional second aperture plate is positioned at the collimating lens and covers top, bottom, and side edge portions of the lens.

Abstract: A precision approach path indicator (PAPI) employs an LED light source with first and second arrays of LEDs or other efficient light sources, disposed one above the other and emitting their respective color lights along an optic axis to a collimating lens of focal length f. First and (optional) second aperture plates positioned along the optic axis, each being a respective frame with a cut-out defining a horizontally elongated aperture for light passing along the optic axis. Intermediate aperture plate(s) can be positioned between the first and second aperture plates. The first frame is positioned between the light source and the collimating lens at the focal distance f from the lens. The optional second aperture plate is positioned at the collimating lens and covers top, bottom, and side edge portions of the lens.

Abstract: An improved illuminated airfield guidance sign of the type used for marking ground traffic routes on runways and taxiways employs LED-based lamps for even illumination of the legend panels. The lamps each employ an array of white LEDs mounted on a generally cylindrical turret, and oriented with the turret axis horizontal, so that the LEDs aim their beams up, down, or laterally, and not towards the legend panels. The illumination has to bounce at least once on an interior reflective surface before reaching the legend panels. These can receive power from storage batteries that are charged from solar panels or wind turbines, with back-up power coming from the standard runway-taxiway power.

Abstract: An improved illuminated airfield guidance sign of the type used for marking ground traffic routes on runways and taxiways employs LED-based lamps for even illumination of the legend panels. The lamps each employ an array of white LEDs mounted on a generally cylindrical turret, and oriented with the turret axis horizontal, so that the LEDs aim their beams up, down, or laterally, and not towards the legend panels. The illumination has to bounce at least once on an interior reflective surface before reaching the legend panels. These can receive power from storage batteries that are charged from solar panels or wind turbines, with back-up power coming from the standard runway-taxiway power.

Abstract: An improved illuminated airfield guidance sign of the type used for marking ground traffic routes on runways and taxiways has a curved face. The sign is capable of withstanding the prescribed wind load tests and at the same time has even illumination across each of its legend panels. The curved legend panels are preferably formed of sheets of acrylic or equivalent substrate with a thickness of about 0.354 inches except at the edges where the edge portion is about 0.220 inches. The edge portion i.e. peripheral flange fits into the grooves or channels along the base and end panels of the frame.