UFC 3-535-01
17 November 2005
3-7.2.1
Each light unit must be frangible mounted. It must contain 2 lamps
minimum, with 3 lamps preferred, and an optical system that produces a horizontally
split, two-color (white over red) light beam.
3-7.2.2
Beginning at the out-board-most units, each unit in a bar is aimed into the
approach at a successively higher angle above the horizontal. When on a proper
approach path, the pilot sees the 2 inboard lights in both bars as red and the 2 outboard
lights as white. As the approaching aircraft settles below the proper path, the pilot sees
an increasing number of red lights in each bar. As the aircraft rises above the path, the
pilot sees an increasing number of white lights. (See Figure 3-12.)
3-7.2.3
The edge of the innermost unit in each bar must be no closer than 15
meters (50 feet) from the runway edge, and the units in a bar must be 9 meters (30 feet)
apart. The beam centers of all light units must be within 0.025 meters (1 inch) of a
horizontal plane. This horizontal plane must be within 0.30 meters (1 foot) of the
elevation of the runway centerline at the intercept point of the visual glidepath with the
runway. The units in a bar must all be within 0.025 meters (1 inch) of a line drawn
perpendicular to the runway centerline. The distance from threshold to the PAPI should
be the shortest distance that will accommodate the criteria contained in paragraph
3-7.4.2.
40
Previous Page
