A-PAPI (Abbreviated Precision Approach Path Indicator) is a two-light visual glide path indicator system installed at airports to help pilots maintain the correct approach angle during landing, especially where space, cost, or operational constraints prevent installation of a full PAPI.
A-PAPI (Abbreviated Precision Approach Path Indicator) is a visual glide path indicator system that uses two light units (instead of four, as found in standard PAPI) to provide pilots with immediate feedback about their approach angle during landing. Typically installed on the left side of the runway, A-PAPI is a solution for locations where installing a full PAPI system is not feasible due to space, cost, or operational constraints.
A-PAPI light units are installed in a straight, horizontal line and set perpendicular to the runway centerline, usually 10 meters (33 feet) from the runway edge. Each unit projects two color sectors—white (seen when above the approach slope) and red (seen when below). The sharp transition between colors allows pilots to quickly determine if they are above, on, or below the optimal glide path:
| A-PAPI Display | Glide Path Position | Pilot Action |
|---|---|---|
| Both lights white | Well above glide path | Increase descent rate |
| One white, one red | On or very close to path | Maintain current approach |
| Both lights red | Below glide path | Decrease descent rate/climb |
Mnemonic:
Modern A-PAPI units use LED technology for reduced power consumption, long operational life, and compatibility with solar or hybrid power sources. This makes them ideal for remote, temporary, or low-infrastructure airfields.
A-PAPI is regulated globally by ICAO Annex 14 and in the US by FAA AC 150/5345-28H . Key requirements include:
A-PAPI may be controlled remotely by air traffic control or by pilots via radio.
| Feature | A-PAPI | PAPI | VASI |
|---|---|---|---|
| Light units | 2 | 4 | 2+ (bars) |
| Glide path indications | 3 (above/on/below) | 5 (finer) | 2 (basic) |
| Typical use | Small/remote | Major runways | Legacy/limited |
| Maintenance | Minimal (LED) | Moderate | Moderate |
A-PAPI is especially favored for secondary runways, general aviation fields, and remote or temporary installations.
A-PAPI systems offer essential, cost-effective visual approach slope guidance for a wide range of airport environments, improving landing safety where full-scale PAPI is impractical. Their simplicity, regulatory acceptance, and adaptability—especially with modern LED and solar options—make them a smart choice for airfield operators worldwide.
Upgrade your airport or airstrip with reliable, energy-efficient A-PAPI systems—offering cost-effective, ICAO-compliant visual guidance for safe landings.
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