BigBadFun said:
Previous and current firmware (v3.04) it justs lands. New firmware about to be released (v3.05) it returns to home point and auto lands.
I don't know if this guy is joking or what but for a Phantom 2 this is not accurate. FYI - the terms "failsafe" and "return to home" (RTH) mean the same thing in the Phantom world.
When you power up the Phantom2 it tries to establish a GPS home-point. This also establishes "ground level" - 0m altitude.
When the lights flash rapid green as described in all the documentation, the Phantom has established that home-point... you can fly before that but any smart pilot will wait for that home-lock before flying. If failsafe is triggered... either by losing contact with the RC or manually via the toggle switch... then one of 2 things will happen:
-if the Phantom is BELOW 20m altitude (from the ground-level @ home point) it will ascend to 20m, fly back over it's home-point, and then descend.
-if the Phantom is ABOVE 20m altitude it will simply fly over it's home point and descend.
I would recommend testing this system so you can see for yourself. There 2 ways you can trigger failsafe:
1) turn the RC off. I do not prefer this method because #2 is so simple.
2) configure the right toggle on your RC to trigger failsafe. details below:
if you have not changed the flight computer out of the default mode (Phantom mode) you may have noticed that the 2 toggle switches at the top of the RC don't really do anything. It is possible via the Phantom Assistant software to set the right toggle to trigger failsafe (or back to NormalFly). In Phantom Assistant, go to the Basic / RC tab. at the bottom is a setting "control mode switch". Notice the only thing you can change is on the right there's a dropdown box where the options are NormalFly and Failsafe. Since the default setting is NormalFly, that's why switching that toggle doesn't do anything. If you change that option to Failsafe, now when you flip the right toggle all the way down, Failsafe / Return to Home will be triggered... but unlike option #1 above (turning the RC off) you're still in live contact with the Phantom and can recover control at any time by flipping the toggle back up to NormalFly.
Sure with option #1 you can just turn the RC back on, but I'd prefer to maintain contact the entire time.
You can test this before you even take off. With the Phanton on the ground with the props off... wait for the indicator lights to turn green.... now flip the S1 toggle all the way down. The green lights should start blinking yellow indicating Failsafe mode. Flip it back up and the lights will go green indicating NormalFly.
Now you can easily and comfortably test failsafe feature at short range... fly off a bit at below 20m and flip the switch. the lights will go yellow, and you should notice the phantom ascend then fly over it's home point and descend. you don't even need to wait for it to fully land, just flip the toggle back to NormalFly and resume control. Fly a little farther away and make sure you're above 20m high and then trigger failsafe again. You should notice it fly overhead then begin descending.
After testing this whole process several times and further and further distances I became comfortable with the fact that failsafe worked properly, and I even started using it as a "come home autopilot" from several hundred meters away or if I was high up in the air (150-250m) letting the failsafe feature descend the craft for me so that I didn't have to just sit there holding the throttle down.
I believe there is a point at which the battery is so low that the craft will just try to land, period. perhaps this is where the confusion comes from? My advice is to fly conservatively... just get additional battery or 2 and rather than risk running 1 battery all the way down, when it gets low (25-30%) just come home and swap batteries. much safer