This is my very simple way to help prevent things from turning my planes off in flight (which is almost always not good):

Billy, eye bolt?

yep and if you need it you can cut two little pieces of wood and squirt some CA on them (to make them tougher), let them dry and screw the eye bolts into them on the interior of the wing. The eye bolts on the Knife are happy just being screwed into the wing.

I use the double switch method so as to have a semi redundant system, one on each side. Since weight can be a factor in some of my planes I use only one battery thus making it semi redundant. The duel battery and switch are more prominent.

Randy

short of running in to a tree what exactly would turn your switch off in flight, streamers wont do it, baloons wont, what are you running in to. curious??? Your not chasin birds are ya billy

There was a whole thread about weeds turning off switches and people hand tossing planes and hitting the switch. I've heard of mufflers coming off and turning off switches. I originally used them because it was all I had at the time but then I decided it was great protection to boot.

I don't know why you folks in Nashvegas want to land in the weeds. Over here in the western part of the state, we land in short grass!

Tim

Well I can better that how about a wide 500' asphalt runway with taxi ways to boot

Blackie

I don't have the movie of this yet but how about doing a dead stick landing in the middle of a 40 acre pasture and somehow landing precisely in the only ditch on the whole place? Well I did it. There is a pic of the plane and then a pic of what it looked like from where I was standing. The plane just seemed to vanish!

And what I saw:

That's spot landing at its best!

Tim

Even on a paved runway, assuming you don't run off into the weeds, a piece of rock or gravel can easily get thrown up and into the switch. Flying at altitude, hitting the switch with a june bug or such could easily flip it off. I agree it's not likely, but it HAS happened and the fix is easy. I always mount mine where off is to the front just for that reason.

Check out this switch. There is no way it can be turned off in flight because there is none of the switch on the outside of the plane when on.

http://www.fromeco.com/products.htm

Glen

Crosswind, true I also position my switches on both side's of the plane so that they are off in the forward position. and on the greatplanes push/pull switch I install it so that the switch is pushed in when on.

KiteGent, any single switch can fail, even the ones that are not supposed to! can fail. Nothing you can do is 100% even my duel switch method is not fool proof. Now if I were to install two of those reliaswitch's then life would be even better.

To have a true redundant system would be to have two fail safe switches and two batteries with switches in the forward position when off. For a kicker lets add another receiver.

Randy

I too have always mounted my switches where forward is off. With a low wing plane it would be easy to accidentally turn the switch off when holding the plane while running up the engine.

As far as the failed switch issue goes, I've never heard of one of these switches failing and causing someone to loose an airplane, though it obviously has happened or we wouldn't be having this discussion. Is this problem really that prevalent?

Keith

Keith, to answer your question be wary of the MPI they are known to fail. This is the only one that I have witnessed so far.

Randy

Ok here's ya another failsafe switch. I haven't built one yet, just cus I haven't got around to it. It is called a phone jack switch. I won't go into detail cus here's enough info to tell ya. I hear good things as well as bad things about these types of switches. So my guess is to use with caution.??.

Here's a couple of threads on rcgroups.com that talk about these types of switches.
Here
Here
More
Last thread


Now here's a site that used to sell the switches but now all they sell are the parts. There's a lot of good pics to give you an understanding of how the switch works too. http://www.hollyday.com/ Under make your own switch jacks.

And lastly here's two links to the products you would need to make your own switch. These could easily be found at an electronics store.
First one
Second one

Josh

Randy,

I'm not familiar with the term MPI. What does that stand for, or is it a brand name?

Thanks,
Keith

Keith, here's the best I can do. I know that out local hobby shop carry's them.

Here is the web site.
http://www.maxxprod.com/mpi-2.htm

Wow! Am I glad we just have big green weeds and not June Bugs.