Position mode and Altitude mode are the two primary assisted flight modes for multicopters. Both stabilize the vehicle so it holds a fixed altitude or 3D position when you release the sticks — removing the need to constantly correct for wind and IMU drift. They differ in one critical way: Position mode requires GPS and holds horizontal position, while Altitude mode works without GPS and only holds altitude, leaving you responsible for countering horizontal drift. These are the recommended modes for pilots learning to fly PX4 vehicles. Position mode in particular is the safest manual mode available — releasing all sticks actively brakes the vehicle to a stop and locks it to its current coordinates in 3D space.Documentation Index
Fetch the complete documentation index at: https://mintlify.com/PX4/PX4-Autopilot/llms.txt
Use this file to discover all available pages before exploring further.
Position mode
Position mode provides the highest level of assisted flight short of a fully autonomous mode. When your sticks are centered (within theMAN_DEADZONE threshold), the autopilot holds the vehicle’s current latitude, longitude, and altitude against wind and other disturbances. When you move the sticks, you command acceleration over ground — not angle and not velocity directly.
How stick inputs work
This acceleration-based mapping (controlled byMPC_POS_MODE) makes the vehicle behave like a car accelerator pedal:
- Roll/Pitch sticks centered → vehicle holds horizontal position; actively brakes if it was moving
- Roll/Pitch sticks deflected → vehicle accelerates in the commanded direction; the further you push, the more acceleration up to
MPC_ACC_HOR_MAX; speed ramps up until reaching the limit set byMPC_VEL_MANUAL - Throttle stick centered → vehicle holds current altitude
- Throttle stick up → vehicle ascends at a rate up to
MPC_Z_VEL_MAX_UP(default: 3 m/s) - Throttle stick down → vehicle descends at a rate up to
MPC_Z_VEL_MAX_DN(default: 1 m/s) - Yaw stick → commands yaw rotation rate; autopilot stabilizes the rate
Landing in Position mode
Position over the landing spot
Use the roll and pitch sticks to move the vehicle directly above your intended landing location. Release the sticks and wait for the vehicle to come to a complete stop.
Descend slowly
Gently lower the throttle stick to begin descent. Keep descent rate slow enough to confirm you are over the correct spot.
Continue descent through touchdown
Continue lowering the throttle stick. The vehicle will slow automatically as it approaches the ground due to the
MPC_LAND_ALT1 and MPC_LAND_ALT2 altitude-based descent limiting.Position loss behavior
Position mode depends on a valid global position estimate. If GPS quality degrades below the threshold (e.g., due to signal loss or too few satellites), PX4 triggers the Position Loss Failsafe. Depending on your failsafe configuration and whether RC control and altitude estimates are available, PX4 may switch to Altitude mode, Manual/Stabilized mode, Land mode, or terminate.Altitude mode
Altitude mode stabilizes the vehicle’s altitude using the barometer (and rangefinder if available) while leaving horizontal position control entirely to you. When you center the throttle stick, the autopilot holds the current altitude. The roll and pitch sticks still control vehicle tilt angle (like Stabilized mode), so the vehicle will drift horizontally if wind is present.How stick inputs work
- Roll/Pitch sticks centered → vehicle levels to horizontal; altitude is held; horizontal position drifts with wind
- Roll/Pitch sticks deflected → vehicle tilts and moves in the commanded direction
- Throttle stick at ~50% → vehicle holds current altitude
- Throttle stick above 50% → vehicle ascends at a rate up to
MPC_Z_VEL_MAX_UP - Throttle stick below 50% → vehicle descends at a rate up to
MPC_Z_VEL_MAX_DN - Yaw stick → commands yaw rotation rate
Comparing Position mode and Altitude mode
| Behavior | Position mode | Altitude mode |
|---|---|---|
| GPS required | Yes | No |
| Altitude held when sticks centered | Yes | Yes |
| Altitude sensor | GPS + barometer | Barometer (or rangefinder) |
| Horizontal position held when sticks centered | Yes | No |
| Actively brakes horizontal motion | Yes | No |
| Wind drift compensation | Automatic | Pilot must correct manually |
| Stick-to-motion mapping | Acceleration (default) | Tilt angle |
| Recommended for beginners | Yes (with GPS) | Yes (without GPS) |
Key parameters
| Parameter | Description | Default |
|---|---|---|
MPC_XY_VEL_MAX | Maximum horizontal velocity the position controller will command | 12 m/s |
MPC_VEL_MANUAL | Maximum horizontal velocity in Position mode at full stick deflection | 10 m/s |
MPC_ACC_HOR_MAX | Maximum horizontal acceleration | 5 m/s² |
MPC_Z_VEL_MAX_UP | Maximum vertical ascent velocity | 3 m/s |
MPC_Z_VEL_MAX_DN | Maximum vertical descent velocity | 1 m/s |
MPC_TILTMAX_AIR | Maximum tilt angle allowed in flight (all assisted/auto modes) | 45° |
MAN_DEADZONE | Stick deadzone within which position or altitude hold activates | 10% |
MPC_POS_MODE | Stick-to-motion mapping strategy: acceleration-based (default) or direct velocity | Acceleration |
MPC_LAND_ALT1 | Altitude below which descent speed is limited during landing approach | 10 m |
MPC_LAND_ALT2 | Altitude below which descent is limited to MPC_LAND_SPEED | 5 m |
MPC_LAND_SPEED | Final landing descent rate | 0.7 m/s |
First Position mode flight
Verify GPS lock
Confirm that QGroundControl shows a solid GPS fix with at least 6 satellites and HDOP below 2.0. The status bar icon should be solid, not flashing.
Check sensor calibration
Ensure your accelerometer, gyroscope, magnetometer, and barometer are calibrated. Review QGroundControl’s pre-flight check indicators — all should be green.
Arm and take off in Position mode
With the flight mode switch set to Position, arm the vehicle and raise the throttle above 62.5% of its full range. The vehicle will take off vertically and stabilize at a low hover altitude. Release all sticks and confirm the vehicle holds its position.
Test stick response
Gently deflect the roll stick to one side and observe the vehicle accelerate slowly in that direction. Release the stick and confirm the vehicle brakes and returns to holding position. Repeat for pitch, yaw, and throttle.
If you switch to Position mode and the vehicle immediately drifts or oscillates, check for GPS multipath issues (flying near large structures) or magnetometer interference (flying near power lines or metal structures). Poor position estimates cause the position controller to overcorrect.