Cheat sheets, parameters and file formats.
PX4 main and ArduPilot Copter 4.6/4.7 parameter references (checked 2026-10-24). Names and defaults change between releases — confirm on your vehicle.
| Setting | PX4 | ArduPilot | DJI Pilot 2 |
|---|---|---|---|
Return altitude On a return the aircraft climbs to this height, then flies straight home. It must clear every obstacle between the aircraft and home. | RTL_RETURN_ALT (m, default 60) | RTL_ALT_M (m, 4.7; default 15) · RTL_ALT (cm, 4.6 and older; 1500) | Pilot 2 › Aircraft settings › RTH altitude |
Return descend altitude PX4 descends to this height over home before landing, so it isn't still high when it arrives. | RTL_DESCEND_ALT (m, default 30) | — | — |
RC loss action What the aircraft does by itself when it stops hearing your transmitter. | NAV_RCL_ACT (1 Hold, 2 Return, 3 Land; default 2) | FS_THR_ENABLE (1 RTL, 2 continue mission in Auto, 3 Land; default 1) | Pilot 2 › Signal lost action (RTH / Hover / Land) and route 'Lost RC' action |
RC loss timeout How long the signal can drop before the failsafe starts. | COM_RC_LOSS_T (s, default 0.5) | — | — |
Data link loss action What happens when the ground station telemetry link drops. Off by default — decide deliberately. | NAV_DLL_ACT (0 Disabled default, 1 Hold, 2 Return, 3 Land) | FS_GCS_ENABLE (0 off default, 1 RTL, 5 Land) | — |
Data link timeout How long telemetry can be lost before the action. | COM_DL_LOSS_T (s, default 10) | FS_GCS_TIMEOUT (s, default 5) | — |
Low battery threshold The first warning. Start heading home. | BAT_LOW_THR (fraction, default 0.15) | BATT_LOW_VOLT (V, default 10.5 on many boards) | Pilot 2 › Low battery warning |
Critical battery threshold At this level the failsafe action happens whether you like it or not. | BAT_CRIT_THR (fraction, default 0.07) | BATT_CRT_VOLT (V) | Pilot 2 › Critical low battery |
Low battery action Warning-only means the pilot must act. Hampton's .02 cents: never fly a mission with warning-only and no plan. | COM_LOW_BAT_ACT (0 Warning default, 2 Land, 3 Return then land) | BATT_FS_LOW_ACT (0 warn default, 1 Land, 2 RTL) | Smart RTH (automatic) |
Geofence action What happens when the aircraft reaches the fence. | GF_ACTION (1 Warning, 2 Hold default, 3 Return, 5 Land) | FENCE_ACTION (default 1 RTL or Land) with FENCE_ENABLE | — |
Fence max distance A circle around home the aircraft must not leave. | GF_MAX_HOR_DIST (m, 0 = off) | FENCE_RADIUS (m, default 300) | — |
Fence max altitude A ceiling. Set it at or under 120 m (≈400 ft) for Part 107 work. | GF_MAX_VER_DIST (m, 0 = off) | FENCE_ALT_MAX (m, default 100) | — |
Takeoff altitude Minimum height a mission takeoff climbs to. | MIS_TAKEOFF_ALT (m, default 2.5) | — | — |
Mission cruise speed Default horizontal speed between waypoints. | MPC_XY_CRUISE (m/s, default 5) | WP_SPD (m/s, 4.7; default 10) · WPNAV_SPEED (cm/s, 4.6; 1000) | — |
Flight mode switch The switch positions must include a mode you can always fall back to (Position/Loiter) and Return. | COM_FLTMODE1..6 on RC_MAP_FLTMODE | FLTMODE1..6 on FLTMODE_CH (default 5) | N / S / F switch on the RC Plus |
PX4 doesn't list CONDITION_YAW for missions, so PX4 headings go on the waypoint (param 4); ArduPilot ignores waypoint yaw, so it gets CONDITION_YAW.
QGroundControl .plan — JSON, fileType "Plan", version 1; mission (plannedHomePosition, firmwareType 12 PX4 / 3 ArduPilot, items), geoFence version 2 (polygon/circle entries version 1, coordinates [lat, lon]), rallyPoints version 2.
DJI WPML .kmz — ZIP with wpmz/template.kml and wpmz/waylines.wpml; namespace http://www.dji.com/wpmz/1.0.2; M30T drone 67/1, payload 53; coordinates longitude,latitude; heights relativeToStartPoint.