I get a lot of enjoyment having the Helicycle back in its nest and preening its feathers. Lately there has been discussions on knowing how much power is available. Several months ago I installed a micro switch that trips a light on in my dash should I ever ask the turbine to max out its fuel control arm, indicating thats all she has. I test the circuitry each pre-flight and the light comes on just before the fuel control arm hits its stop. To date, I havent seen the light so much as flicker, even hovering and taking off aggresively on a 98 degree day.
The switch idea was prompted to existence when I asked my turbine to go above and beyond when I had my flameout. That light would have come on and told me to back off that collective. With this latest power available discussions, I have decided to put another microswitch that will be triggered when the fuel control arm is around 90% or so. It will be adjustable and will give me an indication when I am asking the turbine to do a lot, but still have some reserve. I would like it set so that the other day when I was full on fuel, and 98 degrees, the light would come on , but the max light remain off. This should be some nice data to have and give me some even better indication and early warning that I am approaching max power.
I already have the light wired into my dash, and it just needs a microswitch to ground it out. My plan is to have a small very light flexible leaf spring trigger the very small microswitch at around 90% travel on my fuel control arm, yet not impede the fuel control arms last movement till it hits 100%. Of course i will make absolutely certain the actuator motor can still operate the fuel control arm to its full rearward stop. A very light miniscule leaf spring is being sought. My plan is to be able to adjust it to make the light come on yet still have some throttle arm travel available for reserve power.
Picture 1 shows the two amber lights , one on the left side and one on the right.
Picture 2 shows the right light on right next to my rotor tach when and if my turbines fuel control arm is at max power. The new microswitch will trigger the left light more as an advisory light saying I am approaching max power. I will set this to come on when the temps are in the upper 90's and I am at full fuel.
Picture 3 is the fuel control arm at idle.
Picture 4 is the fuel control arm at roughly 90%. I am estimating that the light will come on around this point...but actual flight testing will overrule my estimates.
When the fuel control arm is all the way to the stop...no picture here...thats when my microswitch triggers the amber light on the right side of my dash.
When I originally wired my instrument panel....I had prewired two red lights for oil pressure warnings from the turbine and the main transmission. The two amber lights were going to be chip lights for the main transmission and tail rotor. I left them deactivated as I havent been convinced the chip lights arent a pain in the butt sometimes. I regularly dump my tail rotor gearbox oil every 10 hours...and check it thoroughly for foreign material. I decided to wire my microswitch a few months ago to the right side amber light for when and if I am asking the turbine to deliver 100% fuel. Now I am using the left light to come on at around 90% , or whatever it takes to come on in when the conditions are in the upper 90's and I am full fuel. My lights were already connected to 12 volts in the panel....and ground wires run inside my wiring harness out to the turbine area. All I have to do is unwrap the spiral wrap, find my labeled wire, and connect it to the new microswitch which will ground it out when activated.
Stan