Figure 4-14 -- Improved Fresnel Lens Optical Landing System (IFLOLS).
The wheels-up lights are a bar of lights located in the approach area for illuminating the
underside of aircraft preparing for landing. This light bar consists of 20 white lights in a
line perpendicular to the extended runway centerline. The light beams project upward
and toward the runway threshold. The light bar is on the same side of the extended
runway centerline as the air traffic control tower.
Runway Wave-Off Lights
The runway wave-off lights consist of six lights: three along each side of the runway in
the touchdown area. These lights present a high-intensity red flashing signal to inform
the approaching pilot to execute an emergency wave-off or missed approach procedure.
The lights are in pairs outboard of the runway edges (see Figure 4-15). The runway
wave-off lights are activated by either the control tower operators or wheels watch.
The red strobe lights are used for new installations and as replacements for existing
installations. The three-lamp cluster, flashing, red incandescent lights are obsolete.