I recently have problems with my fixed wing.
The Altitude in RTL being too low so I risk smack in to trees. Tried different things but finally tried to set the RTL_ALTITUDE = -1
I was expecting the altitude would stay the same as whatever altitude the plane had before it entered RTL (plus whatever RTL_CLIMB_MIN=50). Document is clear about this. But to my surprise RTL still initiate a Descend command and getting close to hit trees.
There must be something I have missed here.
Or Arduplane is revolting on us all?
I have the bin log file and will upload in minutes.
This is a quad plane, so things get messy. Q_RTL_MODE is 2 (RETURN FIXED WING, LOITER TO ALT, SWITCH TO QRTL, LAND)
In that mode, the plane will travel towards the home point and then loiter around it while descending to the Q_RTL_ALT (set to 0). Then exit into the wind and switch to quad mode to finish the landing.
I’m not clear how the RTL_ALTITUTDE, -1 and Q_RTL_ALT,0 will mix, but my first suggestion would be to set the Q_RTL_ALT to a safer height (40m?) and try it again.
It’s late here so it will have to be tomorrow, but this might be a good one to play with in the sim to work out the details. I use Q_RTL_MODE,3 because I find that loiter circle in mode 2 too risky for some of the places I fly.
Absolutely brilliant Allister.
Yes this is a quadplane and I did not think any Q- settings would apply when flying non vtol.
You got me unstuck in less than an hour. I have been discussing this with ChatGPT the last 4 days
I dont have a SIM set up so I will do things in the field.
Starting with setting Q_RTL_MODE,0
I expect to see no descend in altitude.
The reason I do not have that set to 0 is because I had some very bad experience when flying with 4G LTE modem and it lost connection at some 2 m and started to convert to fly mode from Q mode. Just got away with it barely.
Enjoy your evening and thanks again
Thank you Allister.
I see the benefit learning SIM in mission planner.
This script looks very interesting. I will look into it, if these new settings do not work for my case.
Yesterday I did two test flights. The first with all held equal only changed Q_RTL_MODE from 2 to 0.
Initially it climbs 50m from the current altitude, when close to home it descends to the original altitude, this case 60m and circles. Thats not really safe since I can fly low like 10m and going back to that altitude will smack trees at home. So changed RTL_ALTITUTDE from -1 to 80m.
Now it climbs 50m initially and then start circling at 80m when close to home.
This will work fine I think.
Happy to hear it’s working. That’s a challenge with Q-planes: there’s so many choices for RTL/QRTL that it can get tough to decide what’s going to work best for you. The sim can really help.
