Rescue¶
Rescue is a panic button. Flip the RESCUE switch and the flight controller levels the helicopter -- flipping it upright first if it's inverted -- pulls up, climbs, and then holds a hover until you take over.
It needs the accelerometer calibrated and turned on.
Setting it up¶
- On the Modes tab, put RESCUE on a switch -- a momentary or spring-loaded switch works well, so it ends when you let go.
- On the Profiles tab, turn on Enable Rescue in each profile you want it in.
- Choose Flip to upright: Flip (the default) rights an inverted helicopter; No-Flip recovers in whatever orientation it's in.
The flight controller won't arm while the rescue switch is on.
What happens¶
| Phase | Lasts | Collective |
|---|---|---|
| Pull-up | Pull-up Time (0.3 s) | Pull-up Collective (65%) |
| Flip (if inverted and Flip is on) | Until upright, or Flip Fail Time (2 s) | -- |
| Climb | Climb Time (1 s) | Climb Collective (45%) |
| Hover | Until you release the switch | Hover Collective (35%) |
| Exit | Exit Time (0.5 s) | Collective changes smoothed, so a sudden negative stick can't drive it into the ground |
With a barometer, Enable Altitude Hold makes the hover hold a set altitude, using the altitude PID settings.
Setting the collective values¶
The defaults are percentages of your collective range, for a typical sport setup. Check them for your helicopter:
- Hover Collective -- set it to what your helicopter actually needs to hover. Too low and it sinks during rescue; too high and it climbs away.
- Climb Collective -- enough for a firm climb.
- Pull-up Collective -- a strong initial pull to arrest a descent.
Leveling Gain, Flip-to-Upright Gain and the Max Levelling Rate and Acceleration set how aggressively it rights itself. Larger helicopters may need slower rates.
Test it¶
Test at a safe height, with plenty of room, starting the right way up:
- Climb high, put the helicopter in a gentle bank, and flip the switch. It should level, climb and settle into a hover.
- Adjust the hover collective until the hover holds height.
- Only then try it from steeper attitudes, and inverted.
Warning
Rescue needs height. From low down, inverted, a flip and pull-up may not finish before the ground arrives.