Part 5: Circuit Position Calls

PAPI — Precision Approach Path Indicator:

Most controlled aerodromes and many uncontrolled aerodromes are equipped with a visual approach slope indicator called PAPI (Precision Approach Path Indicator). PAPI consists of four light units installed beside the runway, usually on the left side, near the touchdown zone. Each unit shows either red or white depending on whether you are above or below the correct glidepath.

The PAPI indications are:

4 white lights = Too high. You are significantly above the glidepath.
3 white, 1 red = Slightly high. Increase your rate of descent slightly.
2 white, 2 red = On glidepath. This is the correct indication. Maintain your descent rate.
1 white, 3 red = Slightly low. Reduce your rate of descent or add power.
4 red lights = Too low. You are dangerously below the glidepath. Add power immediately and climb back to the correct approach path.

PAPI provides continuous visual guidance and is especially useful on clear days when there is no ILS available. The standard glidepath indicated by PAPI is typically 3 degrees, which matches a standard visual approach slope.

While PAPI itself is not referenced in standard ATC phraseology (the controller will not say "check your PAPI"), ATC may report the approach lighting status during ATIS or in response to a request: "Approach lighting and PAPI runway one-five available." As a pilot, your use of PAPI is visual and does not require radio communication.