Meaning: high, medium and low intensity runway lights. These lights have three intensity settings: HIRL, MIRL and LIRL. The runway thresholds are either green or red. Edge lights are white except for instrument runways where the last 2000 feet is yellow. They can be omni or uni-directional and are mainly used in circumstances of reduced visibility. REIL (Runway End Identifier Lights) are a pair of synchronized flashing lights positively indicating the approach end of the runway. The runway itself is also marked with lights, predominantly with end identifier, edge, centerline and taxi lights as discussed below. These glideslope angles may vary due to obstacle clearance requirements. The glide slope indicated by a two bar VASI is 3В°, the three bar VASI have two glideslopes: 3В° and for high cockpit aircraft a glideslope at 3.25В°. The installation of a VASI (Visual Approach Slope Indicator) consists from 2 up to 16 light units arranged in bars (near, middle and far). Descend should not start until the aircraft is aligned with the runway centerline. They are visible from 3 to 5 miles during the day and up to 20 miles at night these lights provide the pilot a safe obstruction clearance within 10 degrees from the extended runway centerline to 4 NM from the threshold. For this visual glideslope indicators were developed. The aircraft needs to stay clear of any obstacles in the approach area.

Glideslope indicatorsД«ut seeing the runway on final approach is not the complete picture. Some systems have a ball of light (strobe) running and pointing towards the runway. They start out from the threshold to a distance from 2400 to 3000 feet for precision and to 1500 feet for non-precision runways. Having intimate knowledge of these airport and runway lights and familiarity with the layout will increase the safety of your night flight operations.ДЄLS or approach light systems are designed to transition from IFR to VFR and help the pilot keeping the aircraft aligned with the runway centerline for landing. After completing the landing, the pilot is guided to his parking position by blue taxiway edge lights. To help the pilot fly a safe approach on finals to the runway a system of lights are used to indicate the correct glide-path and alignment on the center line, these lights are located left or right to the runway and are visible some distance away. They are sometimes switched on, even on request, for VFR pilots in reduced visibility conditions with a low sun angle when the runway aligns in the direction of the sun. There are also light configurations for non-precision approach runways. The image shows the precision approach lights. Runway lights provide the means for the pilot to transition from IFR to VFR flight just before landing.