Please fill (me) in the missing part of the text!

Here`s how a failsafe works on your model aeroplane.......and that`s how a failsafe works on your model aeroplane!

Well I had a battery fail midflight and the rx never rebooted. I lost all control and the properly trimmed tiger moth made one of its best landings ever.
Just don't try that with out dihedral.

Failsafe is a new plane from the LHS


Thats all I got.

If you have a RC xmtr/rcvr pair that has failsafe mode it works thusly:

You program each channel with a failsafe position - example: Throttle - off, rudder - slight turn, elevator - neutral.... these are the control positions that will occur if radio signal is lost for more than a fraction of a second.

In this example, if radio signal is lost, your plane's reciever would kill throttle, and make a slow, descending turn until signal is regained.

That's how it works... if your system has it.

So is this something one would look for as a separate unit, or are we talking RX-failsafe "systems" here that effects the whole RX? Any recommendations would be nice as i have no chlue what to look for. I`m not flying any really big expensive piece of machinery, but i do find myself in distress from time to time with my flying machines, so i wonder if a failsafe would relieve some of that crash science agony. So we are talking about using a failsafe as a means to glide our models "in" at a certain trim, yes?

Different makes/models of transmitter, different styles of failsafe.

But in general it's intended to prevent flying away if you lose the signal. It will NOT save you from crashing. All the failsafe can do is set the controls to a predetermined state. The chances of that state being what you needed to save the plane are almost zero.

Many people set failsafe to throttle off and flight controls to something like full UP and full left. That way the plane will usually crash relatively slowly. If you set it to something like QuadManiac suggests that only works if the plane was initially flying straight and level....if it was diving into the ground it just carries on doing that right up to the crash.

Steve

Probably the two main definitions of 'failsafe', as already hinted on, are -

It doesn't go out of control if it looses the radio signal, (but you may never see the plane again as it flies away).

It goes into a semi-controlled crash nearby, (so that there is a good chance of you will retrieving the bits).

Some model have an 'Anti Crash Technology', (ACT), system fitted, though many will recommend it is turned off, as it can cause crashes, (allegedly ).

The best 'failsafe', (but you can never stop crashes), is to always fly when the weather is more suitable, always try to fly up-wind, and practice, practice, practice.

Having a model crash just has to be an accepted possible outcome from the hobby, or as some of us more experienced fliers would put it,......'a golden opportunity to build/buy a another model'.

A failsafe is a setting on your receiver (not available on all brands). Look in your manual for details.
Typically, you set the failsafe positions by holding the position you want on the transmitter (powered on), and then power on the receiver.

Other then smart failsafe on my spektrum receivers that move the throttle positions to the lowest point to stop the motor having failsafe on my other models won't help them.

But I would like to have preset failsafe on my glider that would deploy the brakes to prevent it from going farther out BUT not every receiver have this feature.

In the case of spektrum and there receiver line up that do have both types of failsafe, not every uses it AND some don't even know HOW to use it meaning they don't know it requires a different bind step in order to activate preset failsafe.

Just been thinking about it. There was a 'failsafe' method used on free flight models to bring them down quickly but safely, and stop the obvious fly away. They would activate a 'dethermalizer'.

The dethermalizer was usually triggered after a set time delay. One method was to tip the tail plane trailing edge up, (horizontal stab), to an angle of 30-45degrees along with cutting the motor if it was IC powered.
The plane would generally nose up, stall, and eventually drop into a flat stall. This would bring the model down quite quickly and often safely.

Maybe a usable method for lighter RC models.

Instead of neutral or slight up trim of the elevator, full up could be deployed and the motor cut.

If you regained the radio link, no problem. If you didn't, then the model hopefully would continue to descend in a flat stall and at least should be nearby when landed.

De-Thermalizer...
There's a UAV that does the same to end a flight.

For MOST receivers, fail safe mode is the position the servos were in when the xmitter and rcvr were bound.

early on in my FPV flying i was flying a converted 2m thermal glider. it was a full mile away and a cell in the 3s battery completely failed, making the entire battery fail. it was not a normal glider, but an older balsa polyhedral glider with a huge amount of wing area. i had the plane trimmed & failsafe set to "porpoise" hands off. where there is positive elevator to force the plane into a mild stall, which drops the nose, which speeds the plane, which creates more lift, which creates another mild stall & cycles.
altitude was... 500'ish feet when control/video was lost.

luckily, im smart and the plane was up wind. thought the plane was lost after 15 minutes with no visual or video feed. then suddenly within a football field of us there it was. about the tops of the pine trees porpoising on along by us.


as for what should your failsafe be. that's a debated topic. some people believe in holding the last knowing position, some set the controls to neutral with no throttle input.
personally.
for inherently stable airframes (large dihedral trainers, polyhedral gliders, delta wing aircraft) i set 1/3 throttle and slight up elevator.
for non stable aircraft (most sport planes, planes that fly "on rails"), hold last known good position on all servos.


the reason you want slight up elevator on planes that are stable in the roll axis (dihedral & delta wings) is NOT to keep it flying. it's to keep the SPEED of the aircraft from rising too much as it continues flying when it eventually is coaxed into coming back down. however it decides to come down. the last thing you want is something going off-axis and pile driving at terminal velocity like a flichette.

even a 2-3 pound foamy will severely dent a steel car body when the motor hits. we've seen it in the FPV section...












and as always the most important thing is to throw away your junky tx's and rx's from spektrum as you fly faster / larger planes that go farther out.