flyer338 Posted March 4, 2020 Report Posted March 4, 2020 I have an electronic ignition and I like the idea of the dual switches with the starter push-button pictured above. When (not if) I am in the air again, I foresee a system with a key operated off-on switch in series with the panel. This preserves the need for a key to start the plane, and the key on the glare-shield signal that the ignition is off. 1 Quote
MoonFlyer68 Posted March 4, 2020 Report Posted March 4, 2020 11 hours ago, flyer338 said: I have an electronic ignition and I like the idea of the dual switches with the starter push-button pictured above. When (not if) I am in the air again, I foresee a system with a key operated off-on switch in series with the panel. This preserves the need for a key to start the plane, and the key on the glare-shield signal that the ignition is off. I have also been thinking about the possibility of the Electro-air switch panel wired in with a key that kills the mags. Like many others, I may be old fashioned but I like the security of having the key in my pocket before I touch the prop. As someone already stated before, if there is a broken wire even the key wont protect us from a hot mag. Quote
FloridaMan Posted May 29, 2020 Report Posted May 29, 2020 I’m thinking this might rewrite the rules on restart at altitude as well as the engine manual specifies not attempting a restart above 18,000 IIRC due to potential internal magneto arcing. Quote
carusoam Posted May 29, 2020 Report Posted May 29, 2020 Above 18k’... With reduced CR for the turbo pistons... Without the turbo spinning... Restart will be difficult until MP reaches a critical value... Restart can occur below a certain DA... with a very lean mixture... This is an important thing to be familiar with for turbo ops... Mags not being pressurized could definitely add to the troubles... Don’t fall asleep and let the fuel run-out ... it’s gonna be a long day... or not long enough... PP thoughts only... -a- Quote
FloridaMan Posted May 29, 2020 Report Posted May 29, 2020 Interestingly enough, the manuals for the TSIO520 mention pressurized mags in the restart procedures. Yet the mags aren’t pressurized in the rocket. Quote
tmo Posted May 29, 2020 Report Posted May 29, 2020 I doubt electronic ignition suffers arcing in low pressure environments, as there isn't anything to arc in the magneto itself, it is all solid-state, timed by a spinning magnet most likely - if 1980's motorcycle technology is a point of reference. The problem with the turbo not making pressure is valid. Well, one could come up with an electric "boost" for the turbo, but that sounds like a solution in search of a problem. Quote
jlunseth Posted May 29, 2020 Report Posted May 29, 2020 “High altitude miss” is a real problem with unpressurized mags in a turbo. Lacking resistance from air, the spark crosses the cap whenever it wants to, to fire a wrong cylinder at the wrong time. Had it happen twice, years ago. Reducing power and getting lower fixed it, but then if you are flying over the Rockies that is not really an option. Whether the Surefly needs to be pressurized would depend on how it is designed, if no way for a spark to follow the wrong path inside the Surefly, then there would be no high altitude miss. I don’t know what the minimum altitude is to have it happen, the times it happened to me I was above 20k. Quote
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.