Don Godfrey has been writing in his "Prez Sez" column about Kill Switches. They should be mandatory, but A switch is not enough! You can't reach an on board switch if your plane is down the runway or in the air. An R/C switch is not useful if the radio malfunctions.

So, my practice is to cover all bases possible - an on board manual (Master) switch, R/C controllable Kill-switch and set the throttle to kill the engine at low throttle, low trim. Not a 100% answer but the best possible under the circumstances. I've had ground wires break from vibration so an on-board KILL switch was useless and was still covered by throttle cut-off. From safety aspects all are necessary!

All Radio Shack Parts
A. Master (Manual) Switch, Submini Toggle 275-324.
B. R/C Switch...Lever Switch 275-016
C. Servo
I make up my own system as follows: Master Switch - manual, off/on (SPST) toggle. R/C Switch - works only if master switch is OFF of KILL (off) position. (A) Active servo to full throw position. (B) Position lever switch to be depressed (slight 'click' can be felt) but don't bottom against the servo arm with any pressure, make this the 'Off' or Kill position. Lever switch has three prongs, one is common and the others are 'off' and 'on'. Use common and on (prongs are marked). (C) 'Hot Stuff' lever switch in position on top of servo. NOTE: 1. Use very little glue. 2. Check switch-mount so seam cracks are up (so no glue gets into the switch)! Use multi-strand wire, connect to coil of engine and ground the case.

Features - Very low priced! Less than $3.00 master switch always 'Kills' engine (grounds out the coil). R/C switch works only when master switch is 'on' and can be used when manual operation of master switch is impossible. Set low throttle, low trim, Kill for back up safety. Position master switch so it is easily accessible. Store the plane with the master switch 'Off' (Kill position) always.