key or keyless

[FlyFastJP]

I got a pretty good deal when I bought my RV-4 because the panel was original to '92 and in desperate need of fixing and updating. Not long after, the key switch started acting up. I wasn't quite ready for a whole panel, so I just cut out the section with the old plastic toggles, removed the key switch, wired in some B&C toggles on a small piece of aluminum, and riveted it back on. Works great for now. I'll get more elaborate with safeties when I actually build a new GRT panel.

I went with toggles because I think it is easier, safer, and more reliable than a keyed set up. I've built a few hot rod cars and always used toggles and buttons. Much simpler to source if one goes bad. And, I know a couple of folks that have lost keys...myself included.

[Robert Anglin]

Originally Posted by Mel

Personally I don't like "key" ignitions. They do fail and the problem is that unless you test the "Off" position periodically, you won't know it's failed. By killing the engine with the mixture, the "Off" position does not get checked regularly. When you do a mag check, you check the left, right, and both positions, but not the "Off" position.

I am now in the process of changing out the key switch on my Legend Cub to toggles and push-to-start switches.

I agree with Mell on this one. But it is what you like and want in your aircraft that matters here. We have a keyed aircraft PMA switch with both Mag's as is standard on most factory production aircraft. Never have had one fail on anything we have had if it was a good make switch that was TSO'ed. We did learn a trick many years ago that we have adopted in our POHB and on any aircraft we fly set up with a standard key switch. We do a run-up then bring the power back down to an RPM just over idle, say 900-1,000. Then I turn the key to off for a spit second for three cycles. This checks the "P" leads for ground on both Mag's as the engine will stop firing on both sides if the grounds are working and helps clean the contacts in the switch just before flight. If the engine does not try to stop firing, we know to go back to the hangar tell we get it sorted-out. Hope this helps someone.
Yours, R.E.A. III # 80888

P.S. We also have a Key on the inside of some panel. I want tell you witch on the aircraft somewhere. That can be gotten at with a simple tool. Also a good idea on road trips to have a Hide-A-Key kind of deal, on board.

[ShortSnorter]

Originally Posted by Robert Anglin

... We do a run-up then bring the power back down to an RPM just over idle, say 900-1,000. Then I turn the key to off for a spit second for three cycles. This checks the "P" leads for ground on both Mag's as the engine will stop firing on both sides if the grounds are working and helps clean the contacts in the switch just before flight. If the engine does not try to stop firing, we know to go back to the hangar tell we get it sorted-out. ...

This was standard operating procedure at the 135 seaplane I operator I worked for.

[Paddy]

Originally Posted by Taltruda

What do you mean "when the engine stops" What triggers the light? A rpm limit value? Or does it need to be at zero rpm to reactivate? How do you wire that it pick up zero rpm?

The engine doesn't need to be completely stopped to engage the starter, if it's windmilling at something less than the preset 600 RPM limit, the starter can be engaged.

The VPX includes a starter protection feature such that the voltage output to the starter switch is inhibited above 600 RPM. This feature makes it possible to have an easily accessible push button that needs no protection from inadvertent activation while the engine is running. I just wired the light on the starter button to show when the starter is enabled (under 600 RPM - light on) vs inhibited (over 600 RPM - light off).

[Snowflake]

I agree with the "keep it simple" doctrine as well, so I have three toggle switches side by side: Left, Right, and Start. Left and Right are ON-OFF toggles, Start is (ON)-OFF (ie. momentary ON). For safety I have one of the military-style red flip-covers on the Start switch, that I have to flip up in order to use the starter. Flipped down it holds the switch in the OFF position.

To protect from the "liability" issue people have, I suppose I could wire a second switch in-line to the Start switch but located out-of-sight on the sub-panel. I'd want to be sure that it was well clear of anything that might move in the cockpit during flight, as I wouldn't want it disengaged by accident and preventing an in-air re-start if needed. I haven't installed one of these yet.

When I bought the plane already flying, it had a Cessna-style keyswitch. I found I didn't like the keyfob swinging around in circles all the time while I was attitude testing.

[gasman]

Originally Posted by Robert Anglin

I agree with Mell on this one. But it is what you like and want in your aircraft that matters here. We have a keyed aircraft PMA switch with both Mag's as is standard on most factory production aircraft. Never have had one fail on anything we have had if it was a good make switch that was TSO'ed. We did learn a trick many years ago that we have adopted in our POHB and on any aircraft we fly set up with a standard key switch. We do a run-up then bring the power back down to an RPM just over idle, say 900-1,000. Then I turn the key to off for a spit second for three cycles. This checks the "P" leads for ground on both Mag's as the engine will stop firing on both sides if the grounds are working and helps clean the contacts in the switch just before flight. If the engine does not try to stop firing, we know to go back to the hangar tell we get it sorted-out. Hope this helps someone.
Yours, R.E.A. III # 80888

P.S. We also have a Key on the inside of some panel. I want tell you witch on the aircraft somewhere. That can be gotten at with a simple tool. Also a good idea on road trips to have a Hide-A-Key kind of deal, on board.

In my past Warrior, the problem was not in the off position, it was that the switch was worn and would go PAST the off position to the left, and everything was HOT again even if you remove the key.

[cajunwings]

To take this a step further: I check key switches as described above but wiggle the key around while the engine is spooling down in the off position. If the switch is a little worn sometimes this will cause the ground to be lost and you can get a mag to fire. If this happens I consider it a failed test and would replace the switch. RV9 will have toggles and starter button.

Don Broussard
RV9 Rebuild in Progress
57 Pacer

[RV7A Flyer]

Just to throw into the mix:

I have a keyswitch (industrial grade from McMaster) to enable the mag switches and starter pushbutton. Key out -> mags remain grounded and starter cannot engage. Key in -> mag toggle switches enabled, starter pushbutton enabled. (The pushbutton is DPDT and simultaneously grounds the right, non-impulse-coupled mag during start).

With the key out, no amount of button pushing or toggle switching will allow the starter to engage, and no amount of dumb-@ssery by kids or spectators messing with the prop will let it accidentally kick over with a hot mag.

Key goes in my pocket at shutdown *every time* for safety.

FWIW, I think a "hidden safety switch" is more likely to be forgotten at some point...out of sight, out of mind, as they say.

[Mel]

Originally Posted by RV7A Flyer

Just to throw into the mix:
With the key out, no amount of button pushing or toggle switching will allow the starter to engage, and no amount of dumb-@ssery by kids or spectators messing with the prop will let it accidentally kick over with a hot mag.
Key goes in my pocket at shutdown *every time* for safety.

But again since you normally kill the engine with the mixture, you still need to periodically "test" the off position of the switch. The typical "mag check" does not test the off position.

[RV-14E]

Originally Posted by Robert Anglin

We did learn a trick many years ago that we have adopted in our POHB and on any aircraft we fly set up with a standard key switch. We do a run-up then bring the power back down to an RPM just over idle, say 900-1,000. Then I turn the key to off for a spit second for three cycles.

Curious...wouldn't that cause a back/after-fire?