I have actually seen the snap-roll fail-safe work very well.. in fact it was several years ago while our flight demonstration team was flying the noon show at a full scale Airshow. My airplane luckily was not involved and because of that fact, I got a good look at how it all came out.

At the time of the lockup we had three airplanes doing circuit fly-bys and mixed septate aerobatic maneuvers. All of a sudden one of them did in fact began a continous snap-roll while climbing out turning downwind. We knew imediately the pilot had lost control! Within no more than 7 or 8 seconds the airplane screwed itself in out in the grass/dirt. We never did find out what caused the fail-safe condition.. but clearly we all became convinced this was the safest way to configure airplanes flying in flight demo's. Mind you this had to of been 12 years ago if it's been a day!

Today I am convinced this is still the safest possible configuration...state of our technology being what it is...the only problem.... and it's a BIG PROBLEM is that at least 75 to 80% of the radios flying today can't be set safely to fly with the snap-roll configuration!

A requirement of the radio is that it's software will allow a 1 second delay or HOLD condition before going to the snap-roll condition. JR's earlier 10 channel radios had a fail-safe feature that would allow the user to set the time delay before surface activation. The later 10X radio transmitting to an S-mode receiver does not have a delay feature. In fact there is NO time delay before activation. Can you see why no one with this type radio wants to hear anything about fail-safe settings other than HOLD...

In fact my two turbine aircraft are controlled using Futaba radios just for this reason! Futaba has for years built-in a 1 second time delay before activation. This means the interference has to last 1 second or more! In providing this delay feature Futaba has thoughtfully allowed the use and setting of a full snap-roll safety system.... or for that matter the safe setting of virtually any fail-safe seting. Caution: do not set fail-safe surface deflection if your radio does not have the time delay feature!

As I have mentioned several times before the reason the turbine manufactures have a time delay feature within the ECU is to allow a shutdown fail-safe setting required by AMA for turbine use! Yep, the most widely used radio the JR 10X would not be usable.... in the turbine world if the turbine ECU did not have the time delay feature included within it's software.
Lee H. DeMary
AMA 36099