ADS-B messages often contain information about the aircraft transmitting the message, including an indication of how big that aircraft is.
There are three classes of "vehicle":
- A (for powered vehicles),
- B (for unpowered vehicles)
- C (for ground vehicles and objects).
| Powered Aircraft |
|---|
| Category | Description |
|---|
| A1 | Light (< 15500 lbs.) |
| A2 | Small (15 500 to 75 000 lbs.) |
| A3 | Large (75 000 to 300 000 lbs.) |
| A4 | High Vortex Large (e.g. Boeing 757) |
| A5 | Heavy (> 300 000 lbs.) |
| A6 | High Performance ( >5G acceleration and >400kts) |
| A7 | Rotorcraft (Helicopters etc.) |
| Unpowered Aircraft |
|---|
| Category | Description |
|---|
| B1 | Glider/sailplane |
| B2 | Lighter-than-Air (e.g. hot-air balloon) |
| B3 | Parachutist/Skydiver |
| B4 | Ultralight/hang-glider/paraglider |
| B5 | Reserved |
| B6 | Unmanned Aerial Vehicle (e.g. Drone) |
| B7 | Space/Trans-atmospheric vehicle |
| Ground Vehicles and Objects |
|---|
| Category | Description |
|---|
| C1 | Surface Vehicle - Emergency Vehicle |
| C2 | Surface Vehicle - Service Vehicle |
| C3 | Fixed Ground or Tethered Obstruction (e.g. radio mast) |
| C4 | Cluster Obstacle |
| C5 | Line Obstacle |
