Having RTL problem

Hi All, I hope I am posting in the right area.

I have a TBS discovery Quad with APM 2.5 and latest MP and firmware wanting to do 1-2 range km FPV. Using RCtimer SK30A esc's and rctimer 750KV motors, imrc 5.8ghz 500mw vtx.

The issue I have is using the 9X tx and rx and I have had numerous problems with the APM flicking into RTL - even though it looks like I have turned off all the failsafes. I have a feeling that the issue is the TX or RX running out of range though last RTL was triggered about 100 meters from the quad, close to the ground causing it to crash.

2 questions that I have if I may;

1. Is there a hardcoded RTL when APM loses TX signal?

2. I am thinking of trying open lrs 433 mhz from hobbyking to replace the stock 9X tx and rx, though I see commonly owners of a 9x upgrade to the frsky 2.4 system or use both. Why would you bother though and just choose the longest range system and stick with that? any feedback on both systems and what I should use? 

Thanks in advance,

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  • Update, I think the problem was the turnigy 9x rx/tx . Setup the frsky two way telemetry system today and no more rtl issues even at 600m. Will keep posted on the next week or so of flying.
  • I just found my tlog on my android device - I thought sharing it may help.


  • I have been having a glitch where it would RTL for no reason while just flying about in Stabilize.  Looking at the logs, I think that the RTL was triggered by a perceived low battery (the battery was fine, but the voltage did drop due to control inputs).  I have disabled low battery failsafes, as far as I can tell, but something appears to be triggering RTL and it coincides with measured love voltage.  It's weird.

  • Might you be hitting the geofence?  100m is the default to trigger rtl. Check the apm settings for geofence. 

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