Hi, I've made the same post on apm, however no one thought it was interesting enough to read, but I badly need some answers from knowledgeable people so doubling it here:
Last Sunday crash-finished my 50+ flight with the current setup. Unfortunately didn't have telemetry as it was a quick FPV fun flight w/o gimbal/gopro so no tlogs. Only APM logs wich I'll be attaching.
Here is the relevant info:
Tricopter 120*, 380kv/4s apm 2.6 w/ external GPS MAG 3DR combo.
running AC3.1.3. (after autotune completed was rock stable, loiter was excellent)
1.2ghz lawmate vTx at 1080mhz channel with a lowpass filter (proven no issues with frsky x8r at 1km)
was flying nearby for 14+ min, flipped RTL just to test -> works awesome, copter comes home, I take over the control and continue in alt hold, switch to loiter, decide to test it again, copter shoots full throttle in the opposite direction it was supposed to go, flipping back to alt hold-> no reaction, continues full throttle "south", flipping to stab, throttle down starts falling, trying to recover unsuccessfully. resulting in 2 broken props (only)
logs show: GPS Err2 right after RTL engaged. (now I know why it shoot "south") but what I do not understand is Err Fligh Mode-5 message right after GPS Err-2, why would a copter fail to enter a flight mode?
also, if anyone has an idea why GPS can throw an error with 11 satellites and HDop1.6 at the time of error rapidly going to 9sats and HDop 1.8 ? could it indicate a bad GPS? (usually I have 11 sats in the first 60 seconds at that very same spot, this time it was only 6 and than 9 later in flight and than 11sats after 10+min)