Tired Old Man

My Feedback: (1)

I guess I'm one of those "foolhardy" people. I use only the throttle and trim or the manually operated switch on the side of the plane. Have since the beginnng a very long time ago. I did have linkage come apart once but I charged my batteies before I flew and simply flew the plane until the engine died and landed it. 25 minutes and having a battery die says something about the owner of a plane. The plane should not have been flying if the battery could not outlast a tank of gas. Don't blame a crashed plane on an engine running longer than the battery could fly the plane. Blame that on a stupid owner. If an ignition battery dies the plane becomes a glider. Gliders fly without engines every day. If you choose to do low hovers and other types of flight where you can't trade airspeed for altitude you simply assumed a much greater risk of loss. Accept it and live with the decision.

I've killed the engine of a plane in flight having a choke servo twice. Both times it was the same plane. A 2.6m Compy belonging to a friend. He uses Futaba, I use JR, so the switch assignments are different. So are trim functions if left in the original manufacturer assignments. The second time the choke control had been moved to a different switch, one I don't normally use, so when I bumped the switch it killed the engine. Both times the plane was successfully dead sticked in for a landing. I've never accidentally killed an engine using throttle control. I do not like to fly his planes because he uses optional engine kills. I'm always nervous when doing so because of the choke servo.

If a situation becomes dire enough I can crash a plane. One should be prepared to do that at any time should the most severe situations occur. I can hit down elevator on a take off or landing roll to kill a prop and engine. Same applies to a low power situation. If you don't know how to fly a plane to a landing under power and maintain control you should still be flying a basic trainer. The condition is nothing more complicated than the basic touch and go. A working or dead engine does not steer the plane, so having it running or off does not protect a crowd. Flight surface controls, restraining the plane during the starting sequence, and safe taxi procedures do that. Toss in range checks, battery checks, equipment pre-flight, and other standard safety procedures and 99.9% of problems are eliminated before an engine is started.

If one elects to use multiple means of stopping an engine in flight that's all well and good, but to state that someone is "foolhardy" if they do not is both arrogant and single minded imo. I'll decide for myself the quantity of redundant systems (if any) I'll install on an aircraft. I will not permit the paranoia of others to effect my decisions.

flaminheli

I opted to not use a servo on the choke. So it cannot be used as a kill device, but it easy to reach thru the front of the cowl to start the engine. I have mine setup so that I can either kill it with the throttle cut or I can use the dial knob that controls the Smart-Fly Opti Kill.

Bob Pastorello

My Feedback: (198)

T.O.M. - no problem!!! I've been told I am far worse things than arrogant and single-minded.
Doesn't change my view on redundant safety devices.
No sweat!

Tired Old Man

My Feedback: (1)

Bob,

Different people have different methods. That does not mean that one is better than the other. Each has their own comfort level based upon their experiences, equipment used, and knowledge. Everything is personal choice, within reason, and each has to make their own call. Is one better than the other? Good question but I don't believe that to be so and will not criticize those at choose a different path. Just I hope those on different paths have the self restraint not to condemn others because they do something differently. As one ages some acquire the wisdom to recognize that one way does not work for all, and if the end result is the same the goals were achieved.

I tend to agree that there a lot of newbies to gas that need all the help they can get, especially where safety and set up is concerned. Many elect to use second and third grade equipment because it's less expensive, while many others fail to research various means of installing and securing items. For them failure will always be imminent until their knowledge and ability levels improve. Some that will always take short cuts and hurry through everything will always have problems. Others, with much more knowledge and experience are likely to rarely, if ever, have a throttle issue. For them lesser quantities of equipment are generally needed. Plus they have the ability to deal with situations as they occur.

The sky is not falling and to have fear for the sake of fear is not healthy, as is having no fear.

Charley

My Feedback: (2)

I don't always agree with Bob but this time I'm in complete accord. I've always had a ignition cutoff switch on my gassers; usually a servo-operated micro switch to disconnect the battery on a CDI or to ground the mag coil on a magneto-equipped engine. My latest project is a Lanier Extra 300L 120-size with a ST 3000 on ignition, which I'm going to try on E85 fuel just for the hellluvvit. It'll have an ignition cutoff for sure. I may try that RCATS relay setup. Looks pretty neat.

CR

Jake Ruddy

My Feedback: (40)

Personally I am a big fan of optical kills. I am not a fan of flying around for 25+ mins at 1/2 throttle because I lost a throttle servo or because a muffler came loose and I couldn't get the idle down far enough. Things happen and being able to kill your engine any time you want is just handy. Required? No, but I would rather spend money on that then a manual switch, I think it's more useful. Let's not forget with a radio or battery problem it kills your engine automatically, a manual switch doesnt.

As far as flipping a switch, well that's your own fault. If your radio has dials put it on a dial. If you don't have dials put it on a switch you don't use very often and that is out of the way. Always show anyone who flies your plane where the kill is so it's not hit by mistake, if they hit it, they didn't listen but if you are letting someone fly your plane I would hope they fly as good or better than you.

Rcpilot

My Feedback: (78)

I don't have that problem because I don't let anyone fly my planes. Fly your own or go sit in the pits with the peanut gallery!! [sm=lol.gif]

Doesn't IMAA have a rule requiring a remotely operated kill switch on giant scale planes? I might be wrong. Maybe it's just a requirement that you have a switch on the side of the plane? Too lazy to look it up.

Flyfast1

My Feedback: (1)

I do like using optical kill switches, even though they add something else that can fail into the plane. I will give one example of a situation where an optical kill switch was very helpful to me. I was flying a 1/4 scale ME109G (about 34 lbs) when I noticed the engine would not go below around 4000 rpm, even when the throttle stick was at the idle position. It otherwise acted normally and I had full throttle control above 4000 rpm.

I flew around for a while at different throttle positions thinking about what to do and actuating the throttle to see if I could free it up and the problem persisted. To land the plane I put the gear down, with no flaps and brought the plane in over the runway. I did one trial pass to check the speed. On the second pass I used my optical kill to kill the engine just after the plane had passed over the end of the runway with the plane about six feet off the deck moving at good speed. I was able to successfully deadstick the plane from that position. Had I not had any type of remote kill, I would have had to fly high and wait for the plane to run out of gas and then deadstick it from there. For me, this approach is fine for many planes, but with this particular warbird, I much prefer to land under power. They can be hard enough to land when everything is working perfectly!

I found out after the plane had landed that the vent line had worked forward into the cowl from vibration and was behind the throttle arm preventing it from moving to idle. A very rare situation that will probably never occur again, but at the time I was glad I had a remote kill method so that I could kill the engine at just the right time on landing.

As for the original question about whether to use an optical kill or a choke servo, I think it depends on the plane. On a plane where the choke is hard to reach, I'd probably use a choke servo for the convenience of using it during starting. If the choke is easy to reach by hand, then perhaps an optical kill switch. I usually program my optical kill switches to the spring loaded trainer switch, which works well for me. It's easily accessible if needed quickly, but doesn't tend to get hit accidentally.

-Ed B.

Rcpilot

My Feedback: (78)

Just add to that, having the optical kill on the trainer switch allows you to sorta pulse the engine if you need too. I've seen a guy land like this. He also had a stuck throttle. It was running about 1/2 throttle and was stuck there. He lined up and used the spring loaded trainer switch to cut power to the engine, and then he would release the switch......... engine would catch and deliver power.......... then he would toggle the switch again and it would slow down the engine........... and he would let go and it would throttle up........ and then he'd toggle it again........... and so on.

He landed successfully without a scratch on the plane.

Tired Old Man

My Feedback: (1)

The IMAA only requires that you have a secondary means of cutting the engine. If it's mad equipped a simple idle cut off meets the qualification as long as their is a standard switch controlling the mag. For electronic ignitions a combination of manually operated switch and idle cut off meet the requirements. Adding another one or two ways of doing the job is up to the owner but in no way required. I do believe that one or two other SIGs have rules requiring a third method such as a choke servo or remote electrical cut.

I've only had a throttle linkage problem on one plane in 40 years so I'm reasonably confidant there's little need to add anything more than I already use. Then again, I triple check all installations and equipment before the first flight and periodically check them again as time progresses. Now if an engine was extremely difficult to access I might add a choke servo, but only then.

cjcyclesrc

My Feedback: (10)

+1 for the optical kill

I prefer to run them and no other ignition switch.

rotccapt

well i think i am starting to lean more toward the optical kill thanks for the insite this will be on wild hare extra

804

My Feedback: (1)

I like the optical kill, I use the Smart-Fly.


Post edited because some people feel they have to pass judgement on every situation presented in this forum.

Tired Old Man

My Feedback: (1)

Sounds like Dawghouse. Without going yea or nay on the optikill, the original problem still likely fell back on an original installation failure (securing connectors) or lack of battery maintenance, such as charging. Either of them a failure on the owners part, not the equipment itself.

flaminheli

I guess one way to look at the opti kill is that it might someday protect a innocent bystandard from an ignorant or just plum lazy pilot .

Tired Old Man

My Feedback: (1)

Nothing will ever protect the innocent from the ignorant or stupid. History has repeated itself too many times for that to be debated.

Bob Pastorello

My Feedback: (198)

Now, Pat, THAT message is one to post as a "universal truth" someplace.
Man, truer words I have NEVER read.... no kidding.

mrbigg

My Feedback: (21)

Just like they had to do in WWI. Cool.[sm=shades_smile.gif]

goirish

Here is a really dumb question from a new gas owner. What is a optical kill (switch?)

flaminheli

[link]http://www.smart-fly.com/Products/Ignition/ignition.htm[/link]

Bob Pastorello

My Feedback: (198)

Generic info - http://www.rcuniverse.com/forum/fb.asp?m=8695728

goirish

I am using a DX-7. Does it mean that I have to have two rx to operate this?

Bob Pastorello

My Feedback: (198)

If you are using all the channels, yes. An optical kill, or a choke servo, either require a dedicated channel available. You have to have individual on/off control like a gear switch, or something like that.

If you have a 50cc gasser, one servo per surface, that's 5 plus throttle is 6, so "kill (or choke)" could be the seventh channel.

I think many DX 7 users probably put the kill on the Gear channel; that's what I did when I was using the DX 7 way back.

goirish

I have at present the choke servo on the gear switch. Should I also have the optical switch? I have a 26cc RCGF on my clipped wing cub. Have not flown or started it yet. Just about finished. Setting the electronics now.

JEFFRO503

My Feedback: (9)

I haven't had the chance to read all the way through this thread yet , but wanted to give my input as well. I have a little 50cc yak i just built and maidened last week , and i could not set up a choke servo on that airplane/motor combo. It just would not work given where the choke is located and how the airplane itself is built.

I do have my throttle set up so if the trim is all the way down , it will kill the motor. I also have 'fail-safe" set up so she goes to idle if i we're to have some kind of a radio issue. I also chose to use a smart-fly optical kill. I had never set one of these up and it was extremely easy , and i honestly feel safer when i'm flying now. Just that little extra safety factor helps the confidence a lot.