Just setting up my first plane with Pixhawk Lite/plane 3.5 and I am witnessing some rather strange failsafe behaviour whilst the plane is on the bench and disarmed, with no available GPS signal.
I am using FrSky Taranis X9D+, so have radio failsafe configured for the no-signal method - the same as I would have it on my multi-rotors (I notice this method is not mentioned in the Plane manual, but on testing it does work).
So on the bench, I have my plane disarmed (ARMING_REQUIRE = 1), and the Manual flight mode is configured. As I am indoors, I should mention that I have no GPS signal (dhop = 99.99).
I then switch off my radio and I see the radio failsafe triggered - all good so far! The plane mode switches to Circle mode as I would expect (given I have FS_SHORT_ACTN set for circle), but then 3.5 seconds later it switches to RTL. Now FS_LONG_ACTN = 1, which tells it to switch to RTL at 5 seconds, so this appears correct, but surely given that I have no GPS fix, this should be falling back to maybe circle?
I have attached my parameter file for further settings info.
Replies
Just updated to 3.5.1 but still have same issue. Basically, in a nutshell, when I get a radio failsafe, it switches to RTL even with no satellite fix present (I.e. testing indoors on bench). This issue when following failsafe test so only USB power, no battery power applied. I would have assumed that on this failsafe if no sat fix was available it should maybe fall back to circle mode. Is this a bug or by design?
I have duplicated this on the bench and yep RTL without GPS. Interesting point Paul.
So what will the AP do with the aircraft if it does not know where it is? but chases are of having NO GPS in flight is very slim.