I had some great flight time today with the new quadcopter w/apm 2.0.. but if you loose radio link.. trouble! (didn't happen in flight, I removed props and tested on my workbench)

I had a great flight today!  The quad soared to over 500ft high.  I select land flight mode and she came down with not problem.  My radio is limited, I've only got a 2 position toggle on channel 5 I figured land was safer than RTL while I am getting used to flying it.   My 2200 3c LiPO only last 5 minutes LMAO.

I've got to save up for a bigger battery now that I know this puppy can carry it and a gopro with no problem at all!   

When I got in the house tonight I decided to remove the props and test to see what would happen if I lost the radio link to my transmitter.     I got the idea to test because I know if I soared too high, too fast I would have been out of range.   Well... I fired up the quad, armed it (with props off of course!) and proceeded to give 50% throttle.    I shut my radio off.  My quadcopter went to full throttle!!!!  If this was during flight she would have ascended until out of power!.. so how can I fix this ?

Is it better to drop to LAND or RTL mode ?  RTL under the worse conditions could fail,   but if you are flying along the surf of a beach or in the mountains LAND flight mode would certainly mean trouble.

How are you programming Failsafe mode ?

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what radio do you have?

A Spektrum DX5e.  I tried to get a Turnigy 9channel mode 2 but hobbyking is always sold out.

Is your throttle still reversed in both the Radio and APM?

I'm no expert on the DX5e, but check what it does for Failsafe.  If it drops the Throttle to zero, and you've got that reversed in the APM, then you'll get full throttle.  You either need to change the Failsafe settings in the DX5e, or (preferably) get rid of that double reversal of the Throttle.

BTW, if you change the reversals, I'd recommend re-calibrating the Radio in Mission Planner too.

Jerry - here is what I posted when you suggested this same question on the other discussion:


Before flying, you should test and find out what happens when you lose TX signal, or you turn off your TX. 

There are several different things that can happen, depending on if you run ArduCopter and ArduPlane, and depending on what your TX & RX models are, and how you have them configured, and this is before you even look at how the APM is configured. 

Many TX/RX systems have their own failsafe settings, and some have default configurations, while others do nothing. Some RX simply hold the same PWM values they had when the TX signal was heard. Others drop all the values to low. Some default to reducing the throttle and push the roll over a bit. Consider that you set up your mode switch, for quads on channel 5. Now, what happens if your RX failsafe standard configuration is to reduce all channels to low? You expect the throttle to go low, right? OK, but what mode do you have configured if CH5 goes low? If it is not stabilize or position hold, then it might be something like Auto, alt_hold, or loiter, so what will your aircraft do? Depending on what mission script you have, it might try to gain altitude quickly, for example.

It is easy to lose your TX/RX link, so you should take the props off, and run some tests, like you said, to find out what it is doing. But I would test inside, using Mission Planner, on the radio configuration page, so you can see what the RX channels do when you turn off your TX, and so you can tell from the HUD which mode your quad goes into.

Does that not make sense? Failsafe climbs then rtl. without props, it was trying to climb but never arrived. 

Thanks for the info. I have throttle reverse on the DX5e, and no reverse on the APM 2.0

I had to because double reverse does not work.  If I double reverese you still need to go to the upper right corder to arm, next position down on throttle stick is full throttle, next from there is low throttle.  I couldn't fly like that so I removed reverse throttle on the APM.      The only configuration you can do to a DX5e is select normal or reverse mode for each channel .  No  failsafe adjustment.

What parameter do I need to adjust in APM ?

You could try reversing the APM and not the DX5e to see if it changes anything. If it does, it possibly means the Failsafe setting (if there is one) is reversed.

According to the manual, if you have the matching receiver (AR600), then when you bind the receiver to the DX5e, the DX5e Throttle setting at that time becomes the Failsafe setting.


The only failsafe feature my radio has is it the reciever remembers your stick and switch positions at binding.

That's the first thing I did when I set up the reciever.  Well... It took 3 attempts for it to program correctly!  Maybe it's due to the Orange receiver I used (Spektrum clone, I had it in my parts box).    I tested failsafe on my bench with a usb connectoin to Mission Planner in the radio calibration menu, and the quad powered with the props off.   I armed the quad,  went to mid throttle, shut the radio, motors shut down and my mode 5 selection (land) was selected.

What parameter do I need to change to get the APM to select land instead of the motors shutting down ?

Do I need to rebind to low throttle and autoland selected ?

Well it time to mow the lawn.

What radio combo should I get for better range ? Now that I know how fast and high this puppy will climb I'd like to

update my radio gear and buy the Turnigy 8000ma 3C Lipo!

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