How to ensure Pixhawk reaches a waypoint's altitude before flying on?

Hi guys...

I fly in mountainous terrain in New Mexico.

I'd like to ensure that my F550 reaches a waypoint altitude before moving on to the next waypoint (more important of course flying UP along rising terrain than the other way around).

Couple questions:

1) Does the Pixhawk do this by default? Perhaps adjusting horizontal speed between waypoints so as to reach the next waypoint's altitude at the same time that next waypoint is reached horizontally? (Seems to be a reasonable safety precaution.)

2) If not, how can I program a flight plan so as to guarantee reaching the next waypoint altitude before moving on?




P.S.  I have been searching high and low for a "complete feature list" of Pixhawk...I find "complete parameter list", and "release notes", but can't find a document that actually says what Pixhawk does in this or that scenario.  Does a document like that exist?  Thanks...

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Copter will reach the altitude you set relative to the home waypoint location. If you need to takeoff at a certain altitude the alt can be set in the take-off command.


I understand the copter may eventually reach an altitude in the flight plan...but will it reach that altitude AT the defined waypoint?

Or will it "fly underneath" the waypoint, trying as hard as it can to make it, and then move on to the next waypoint before that previous waypoint's altitude was reached?




I replied to your post on the APM forums as well....

but here is a parameter list for Arducopter

I believe your question is will the copter fly in 3 dimensions to the waypoint and if the copter is under powered will it just move on if it can not get high enough.  In my experience the copter does fly in 3 dimensions and will get within range of the way point before moving on.  It will slow the copter and then just climb up to the way point before moving on.

The only time I seen that it did not do that is when using Spline waypoints.

Climbing adds a little issue with going over the high altitude mark of 100 meters which will cause the copter to RTL.

Also thinner air means less thrust available.


I think the "Verify height" option in the flight plan tab is supposed to use google earth topography to ensure your however many feet above the terrain, versus feet above launch site.

Here's the page

Mario...thanks for the reply (again)....but didn't we agree over at the APM forums that copter (unlike plane) does NOT have a parameter to guarantee the Pixhawk will reach a waypoint's altitude before flying on to the next waypoint?




Yes indeed, "verify height" does add Google Earth terrain elevations to the altitude of the armed/takeoff spot.

But what I want to know is will the copter adjust it's horizontal speed so as to actually REACH that waypoint's altitude?

And if not, how can I create a flight plan that will not let the copter go past, say, waypoint 1, without first attaining waypoint 1's altitude.





Can you explain this statement further?

"In my experience the copter does fly in 3 dimensions and will get within range of the waypoint before moving on."

What do you mean by "within range"...I don't see a VERTICAL copter parameter that defines to the Pixhawk when it has attained "in range" vertically.

And are also saying that spline waypoints don't work (in the sense of course of the Pixhawk reaching the waypoint's altitude).

And I'm sorry, but I don't understand your comment about "100 meters"....your copter does an RTL if you plan a flight at or above 100 meters?





I exactly know what you mean.
Pls download PC Ground Station from

PDF file format.

If you set waypoints, flight parameters, flight times, mission should be verified first by Pixhawk to know if the mission is possible and can be executed.

Manual comes from DJI but generally problem is alike since
you can plan impossible mission, setting times, flight speed, waypoints, to fool your drone, so mission impossible should be rejected before take off.

.but will it reach that altitude AT the defined waypoint?


plane is different as the default behaviour is that if it cannot ascend or descend fast enough it doesn't try. Copter always reaches the ALT specified 

Bill, I can only give you and educated guess from observation.  From my experience, I also flew in NM, Jemez Mountains (6600' to 9000' alt), NW of Albuquerque.  I now live in Florida.  It always appeared to me that my quad would reach the altitude at or before the waypoint was reached.  I never verified this with logs.  I also never made huge altitude changes between waypoints, especially when going up terrain.  It would suggest setting a mission in a wide open area and simulate what you would do in the mountainous terrain and then look at the logs to see if and when the the altitude and waypoints were reached.  One would need to read the code to find out what happens to the next WP if altitude is not reached for current WP.  I would hope it would not continue unless next WP is at or below current altitude.  A developer may be reading and can answer without us needing to read the code.  I haven't found an answer in several searches

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