I'd like to arducopter to limit airspeed so as to maintain altitude

Id like to to be able to pitch forward for max speed, but have the flight controller automatically limit the speed so as to maintain altitude.

In other words, I want the flight controller to absolutely maintain altitude no matter how far I push the stick forward. I know I can limit the deck angle manually with the stick or in the parameters, but it seems it should be easy for the flight controller to do that automatically?

Is this possible?


See the exact same topic over here:

Thanks for that.

Honestly I find it quite strange that the flight controller can’t be programmed to maintain altitude by slowing down.

Of course I’m no programmer. :slight_smile:

And this is a safety issue as well…why does the programming allow the copter to enter an uncommanded descent? With all the capabilities to do so much math inside the flight controller, it’s really not possible to add the line:

IF alt = descent, THEN slow down?

This function is already included. See Wiki:
ATC_ANG_LIM_TC: Angle Limit (to maintain altitude) , Time Constant
Range: 0.5 - 10.0s

You can set the time in s, after the Controller is limiting pitch if copter can not keep the altitude. So exactly what you want.

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Harald…thanks for that. I’ll give it a try.

Harald…I’ve searched and searched for that parameter…ATC_ANG_LIM_TC doesn’t exist in my full parameter list (Copter 3.7)



If you are in a guided mode that is the default.

I have increased performance in Loiter to the point where thrust exceeds lift and the copter pitch’s back when it sees the altitude decaying.

You haven’t said what flight mode you want this in.

Mike…thanks for the reply.

Well… I guess I’d like the quadcopter to maintain altitude in any mode that uses altitude hold.

I’d rather not have to worry that the airframe might be descending because I pushed roll/pitch stick too far.

I have limited my bank angle to 30 degrees, but I’d like to pitch over further (if possible) if Pixhawk would automatically limit the bank angle so as to maintain altitude.


ATC_ANG_LIM_TC should be there too, default is 1, maybe try 0.5 and see what difference it makes.

Please post a link to a recent log file (.bin) plus some technical specs: batteries, motors, prop size, all up take off weight and so on.