Some will attest this is an area that is a pet peeve of mine.

The IMAA was the organization that came up with the dual ignition kill requirement for gas engines. The IMAA is an AMA SIG so those rules were accepted by the AMA a long time ago. Bear in mind that when the requirement was developed the vast majority of gas engines were using magnetos, which remain hot all the time unless an electrical interrupt is incorporated. Improperly adjusted carb linkages did not always cut the engine, and a hot magneto kept it running. So the regulation simply added the inclusion of a user operated ignition interrupt switch in addition to idle cut off. That switch was intended to be a manually operated switch on the exterior of the aircraft that was manually/physically activated after landing. IMAC may now have some rule forcing use of an electronic kill but if you like being able to always have fun you might not like IMAC.

There is no formal AMA rule that insists a remote operated choke or remotely operated electronic kill be incorporated on the plane. A lot of people that have never read any regulations at all have listened to people that know only marginally more than themselves and come up with the concept that kill devices are mandatory or make flying gas engines safer. Essentially "tribal knowledge" has been used to develop products to generate greater profits. Then fear of the unknown was promoted to embed the concept even further. Clubs that incorporated an electronic ignition kill rule did so out of ignorance.

An electronic kill is not a bad thing but not a requirement. They should not be "forced" on people because of someone elses fear, unsupported allegations of enhanced safety, or unfounded claims of an equipment requirement. Any enhanced level of safety is 100% dependant on the person using the radio, especially where a plane might become uncontrolled on the ground. If the user isn't extremely fast it won't do a bit of good. How many times have you seen someone on the flight line freeze at the controls because they didn't know what to do? How many times were gound incidents the fault of a glow flyer versus a gas flyer? For the most part there is only the idle cut off available for use with glow engines and those are generally considered safe and acceptable for propellers spinning at higher RPM than a gasser. There are some fuel cut off devices for glow engines used in specific competition fields but they are not generally found on sport planes.

If enhanced safety is truly the goal, people would be setting up their failsafes at the radio to send the plane into a terminal flight path in the event of radio failure. That same failsafe could set the throttle to idle or idle cut off, killing the engine, thus reducing the amount of energy during impact. A great many people only use the factory default for their failsafe, which typically holds servos at their last commanded position. Not very smart or safe at all. As far as linkage failures are concerned, if people quit removing the idle return springs on carbs the carb would automatically go to the cut off position and kill the engine if the linkage fell off. This is guaranteed if the idle stop screw was removed from the carb. Been there, done that. We're not flying a weedeater so that screw is uneccessary. Mathmatically, the odds of needing an electronic cut off in an emergency are astronomically high if everything else was done close to correctly. I know that some people are still using less advanced radios that do not have a failsafe function but those people have become few and far between with the advent of 2.4 technology.

If people are truly concerned about safety they would take the time to learn the various functions and how to use their radios, learn how to inspect, install components correctly, and apply that knowledge. They would range test their equipment at minimum before the first flight of every flying day. They would not fly alone at any time, and they would not fly solo unless they were truly qualified. They would also not be flying aircraft or equipment they were not qualified to use. They would not reach around propellers from the front of the aircraft to adjust needles or remove glow drivers. They would ALWAYS have a second person restraining a plane when starting it. They would read and at least acknowlege the AMA safety rules and not fly over or behind the pits. I used to be a club safety officer and have seen all the above and more every flying day. It was a full time endeavor to "enlighten" modelers about protecting themselves from themselves. An endeavor that was often not received favorably by the guilty parties.

On any given day at the field, how many times have you seen one or more of the above violated? How many times was it done by a glow flyer? How many times was it done by a gas flyer? How many times was it done by those with a lot of knowledge and experience? I think you"ll recognize where I'm coming from after those considerations and make the same determinations. Gas flyers are not more dangerous than anyone else. Since they are a smaller percentage of the enthuasists present, by numbers alone they are a lessor risk. The glow flyers are the majority of the people involved in modeling accidents so if there is a need for specific engine safety equipment that's where the focus should be directed.

So that's my story and I'm stickin' to it. It's a hot button topic for a lot of people (especially me) and disagreement is assured. That's OK because it promotes deeper thought and contemplation where model operation safety is concerned.