I need a bit of help. Today, after 2 years and 100's of flights, I lost my plane due to low RSSI Failsafe. The problem is, I failed but not safe.
The low RSSI happened without warning. It was not a graceful degradation that usually occurs but a 2 second okay >>> fail.
The issue is the plane went into circle but applied no power to motor and the elevator was at -14 degrees!! The plane lost altitude and crashed into a fence. It was stolen before I could retrieve it. :-((
Why doesn't failsafe result in full power and climb??? Did I set it wrong? This is the first time I've actually had an all out failsafe. Well, it didn't work!!! Very disappointed!!
I thought you must have a .tlog when you said your elevator was -14 degrees. Now I understand that your pitch attitude was 14 degrees nose down.
Perhaps this is the parameter you are seeking:
Return to launch target altitude. This is the altitude the plane will aim for and loiter at when returning home. If this is negative (usually -1) then the plane will use the current altitude at the time of entering RTL. Note that when transiting to a Rally Point the alitude of the Rally Point is used instead of ALT_HOLD_RTL
What was that set at? Were you flying above that altitude? If so, the plane will cut power and descend to reach it. Maybe you made the mistake of thinking this parameter was in meters while its actually in cm Perhaps you entered 100cm altitude for the plane to RTL at.
This is why I have been wanting your parameter settings. I'm sure you saved a copy of them somewhere.
It really would help to have some logs to look at :-)
What mode did the OSD say that the APM was in at the time of the incident? CIRC, RTL?
The failsafe circle mode will keep constant altitude, so stay at whatever altitude you started the failsafe at. If you had TERRAIN_FOLLOW enabled then it will even go up and down while circling based on the terrain below that part of the circle (this assumes it had managed to download the terrain data from the GCS).
Do you have any logs at all? Even from a previous flight? The logs tell us your settings.
It's worth pointing out that if you expect some feature to work, you should at least test that it works in a safe environment before relying on it. This lesson would be from flight testing 101, I'm guessing...