You’ve probably seen runway approach lights at larger airports many times during your training and when flying at night. These systems take on additional importance when flying IFR since they provide the basic means to transition from instrument to visual flight for landing. 

If an approach lighting system is available for a runway, the symbology will be displayed in both the small airport diagram in line with the runway, and in the briefing strip towards the top of the instrument approach chart. You can then refer to the legend in the digital terminal procedures supplement to determine the specifics of the lighting system.

Approach light systems are a configuration of signal lights starting at the landing threshold and extending into the approach area, at a distance of 2,400 to 3,000 feet for precision instrument runways, and 1,400 to 1,500 feet for non-precision instrument runways. Some systems include sequenced flashing lights which appear to the pilot as a ball of light traveling towards the runway at high speed—nicknamed the rabbit.  

Approach light systems deserve special attention twice during each flight. First is during your preflight preparation, when you can determine which system you’ll see for a particular runway. Here’s the ILS Runway 29R approach at Torrance, California.  Notice the A-5 found in the briefing strip on the approach chart.

Now look in the supplement to find that A-5 represents a medium intensity approach lighting system, or M-A-L-S-R, with runway alignment indicator lights. The inverted dark coloring of the A5 symbol means the approach lights are pilot-controlled.

Approach lighting systems are critical during low ceiling and low visibility conditions when you must decide whether to continue to land or execute a missed approach. If when reaching the minimum descent altitude or decision altitude on the approach and you have the approach lights in sight, you are permitted to descend to 100 feet above the touchdown zone elevation published for the runway. When reaching 100 feet above the touchdown zone, you then must have the runway environment in sight (as specified in § 91.175) and verify the flight visibility is above the published minimums to continue the descent to landing.

If a NOTAM indicates part of the lighting system is out of service, refer to the inoperative components table to make adjustments to the landing minimums. Make it a point to check your destination against the inoperative components table each time you fly IFR to see if the airport has any lighting systems affected.

Remember, these approach lighting systems are an important part of your IFR training. When you arrive at an unfamiliar airport with reduced visibility, let your preflight preparation and knowledge of the various systems lead to quick orientation to the runway. 

Now let’s take a look at the approach lighting systems you are likely to encounter and see what they may look like in a variety of weather conditions.

Approach Light Systems Simulator

Approach Lighting Systems Scenarios