Pmerems

Pmerems

Well Known Member
Advertiser
Gents,

I am laying out my instrument panel and plan on having a switch sub-panel beneath the panel. I am also using center mounted engine controls.

I don't know the sub-panel is really is the best location for the mag switch because the key will be on key chain and my knees will most likely hit it during flight ( I have long legs). I have seen other layouts where the mag switch is mounted to the far left side high on the instrument panel. This location also seems a bit award.

My instrument panel space (right side) is limited by the 3 1/8" Altimeter and Airspeed indicator mounted next to the Dynon 180.

For those who are already airborne (IE flying their dream) I would appreciated input as to your recommended location. I don't want to find out after I flying that I wished I had relocated the switch.

Paul
RV-7A (finishing kit)
 
Drop the key switch and just go with two toggles, one for left and one for right. A key switch won't make the airplane any more secure from theft.
 
As I understand the rules, an aircraft must be double locked.

For example, a keyed mag switch and a canopy lock counts as two locks, while a locked gate at an airport or a hangar counts as one lock.

Tying down at an unsecured airport would imply two locks on the aircraft itself.

An obscure regulation brought on by you-know-what.

Vern
 
osxuser said:
Drop the key switch and just go with two toggles, one for left and one for right. A key switch won't make the airplane any more secure from theft.
Click to expand...
Last year at SnF I was 100 feet from a "keyless" plane on display that started and took off full throttle jumped a ditch, crossed a busy road, and hit two parked cars. The "pilot" was uninjured, but clearly shaken up. After sitting the in cockpit a would be buyer pushed the starter button. Well, guess what, it worked. :eek: :eek: :eek:
 
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Geico266 said:
Last year at SnF I was 100 feet from a "keyless" plane on display that started and took off full throttle jumped a ditch and hit two parked cars. The "pilot" was uninjured, but clearly shaken up. After sitting the in cockpit a would be buyer pushed the starter button. Well, guess what, it worked. :eek: :eek: :eek:
Click to expand...

What do you think about that, OS10???????
 
vlittle said:
As I understand the rules, an aircraft must be double locked.

For example, a keyed mag switch and a canopy lock counts as two locks, while a locked gate at an airport or a hangar counts as one lock.

Tying down at an unsecured airport would imply two locks on the aircraft itself.

An obscure regulation brought on by you-know-what.

Vern
Click to expand...

Hmmmm.. That would put just about any plane larger that a piston single in non-compliance.
 
Vern is correct, isn't he? From what I've understood there must be two locks. One on the door/canopy and a keyed ignition would work. Almost all certificated single-engine piston aircraft thus meet the requirement (but perhaps not the larger a/c as Ron suggests?). If you don't have one of those two you'd need to use a prop lock or a throttle lock, no?

I've been planning on putting a keyed ignition in as well, not only because it requires one less switch hole but especially because it would satisfythe letter of the regs, even if it wouldn't really make the plane THAT much more secure. I really do not want to carry around a prop lock or install a thottle lock every time I park outside the hangar, though I probably would if parked overnight.

To get to your original question Paul, it probably depends on how close your legs are to the panel, but there shouldn't be much on your keyring anyway to hang down and bump into your legs. Having something heavy and flapping around isn't a good idea. Mine has been just a key and the smallest keyring I can find, just to help me keep from losing it.
 
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vlittle said:
As I understand the rules, an aircraft must be double locked.

For example, a keyed mag switch and a canopy lock counts as two locks, while a locked gate at an airport or a hangar counts as one lock.

Tying down at an unsecured airport would imply two locks on the aircraft itself.

An obscure regulation brought on by you-know-what.

Vern
Click to expand...
Vern:

I use two toggle switches for ignition. I have a canopy lock and a Throttle lock that slips over my center mounted throttle in my RV-6.

I have been in and out of this county (USA) several times since 9-11 with out any problems or hassle from TSA. The only thing that TSA asked me in one of the forms that I filled out before I left is was the airplane SECURE. I answered yes and they sent me the waiver I needed to get back in the country.

What is the regulation that requires TWO locks? Where is it referenced?
 
From a reliability standpoint I'd recommend the simple, toggle and momentary switch arrangement. I went with a key switch on my current plane but would not do it again. Other secondary safeties and/or locks could be easily designed into the system which wouldn't reduce reliability.

But if you want the key switch, go for it. Probably somewhere (laterally)opposite the throttle and mixture.
 
Double Locks

I too would be interested in the Regulation "Chapter and Verse" on the double lock regulation. The regs are always open to interpretation and if you look far enough you can find another regulation that will be contradictory.
There are a number of planes with switches that have been started and plowed into cars also. Probably more have run away with keys than without keys making for an argument that keyed planes are less safe than ones with switches. :) As my old boss use to say "you can't fight dumb!" If you have a person that is unfamiliar with the plane don't leave him or her alone with the key or the switches.
 
Back to the original question...

Anywhere that you can have one hand on the engine controls and the other on the switch. In my -8 it is the reverse of yours, engine controls on the left and the switch on the right. You don't want to be doing some strange contortion to get to the throttle on start.

On the toggle/key switch discussion, I am in favor of the keyswitch because it offers some indication the the switch is, indeed, off and lowers the risk of someone inadvertantly throwing a few switches. My practice is to leave the key on top of the panel when I am working around the plane. That way I know that the mags are off. The security angle of a keyswitch by itself is very small, a proplock is probably a much better defense.

John Clark
RV8 N18U
KSBA
 
That's strange. As far as I know, brand new aircraft coming out of American Champion (Citabrias, Decathalons at least) have the same over the shoulder mag switches and the same starter button as they've had since...well...forever. Someone correct me here. The only lock I know of is the door lock.

The "security" of those cheap keyswitches is so awful to begin with (the door locks are even worse) it makes be wonder if the keyswitch wasn't just a convenient way to save panel space and also let the impulse coupled mag do it's thing?
 
Pmerems said:
...I would appreciated input as to your recommended location.
Click to expand...

I don't have an opinion on where to put your key switch. I will mention, though, that just because it says "Start" on it doesn't mean you can't have a seperate starter button. You could put the keyswitch where you wanted, out of the way somewhere and then stick the starter button in wherever is convenient. :)

A keyed switch in some corner of the panel is significantly less awkward if you don't have to reach over to hit the starter.

my $.02
 
RV6_flyer said:
Vern:

The only thing that TSA asked me in one of the forms that I filled out before I left is was the airplane SECURE. I answered yes and they sent me the waiver I needed to get back in the country.

What is the regulation that requires TWO locks? Where is it referenced?
Click to expand...
Maybe "gust lock" counts as a lock.
 
Paul,
I also used the sub-panel for all switches and controls on my -6A.

I located the starter switch on the far left end of the subpanel next to the fresh air vent. That way, the right hand was free for throttle, etc.

The switch has been trouble free for six years and 700+ hours. Of course, it could die tomorrow! ;)

Wes Hays
Winters, TX
RV-6A 700 + hrs
RV-7A Finishing Wings
 
jcoloccia said:
I don't have an opinion on where to put your key switch. I will mention, though, that just because it says "Start" on it doesn't mean you can't have a seperate starter button. You could put the keyswitch where you wanted, out of the way somewhere and then stick the starter button in wherever is convenient. :)

A keyed switch in some corner of the panel is significantly less awkward if you don't have to reach over to hit the starter.

my $.02
Click to expand...
They also make keyswitch that do mags only. I think those are greared toward the pull type started/handprop airplanes, but will certainly work in our airplanes.
 
Starter's the key?

To help with starting, its useful to be able to operate the throttle and/or mixture at the same time as the starter - so one should fall easily to each hand. Position of the mag switches is probably not important except they should be accessible in emergency to shut down the engine.

I think some states tried to introduce legislation concerning double locks, but were put back in their boxes by the FAA who reminded them that only the Feds could require aircraft to be modified. I think the link Vern provided refers only to DOI aircraft. I agree that although it might appear sensible, in reality two locks provide very little in the way of additional security, except for opportunists.

Pete
 
Paul Thomas said:
They also make keyswitch that do mags only. I think those are greared toward the pull type started/handprop airplanes, but will certainly work in our airplanes.
Click to expand...

I didn't know that. Neat. Any idea where to buy one of those?
 
John Clark said:
Anywhere that you can have one hand on the engine controls and the other on the switch. In my -8 it is the reverse of yours, engine controls on the left and the switch on the right. You don't want to be doing some strange contortion to get to the throttle on start.

On the toggle/key switch discussion, I am in favor of the keyswitch because it offers some indication the the switch is, indeed, off and lowers the risk of someone inadvertantly throwing a few switches. My practice is to leave the key on top of the panel when I am working around the plane. That way I know that the mags are off. The security angle of a keyswitch by itself is very small, a proplock is probably a much better defense.

John Clark
RV8 N18U
KSBA
Click to expand...
John,
Don't depend on the ignition being off just because the key is "out". I have seen key switches that were either worn or defective that the key would come out in the "left" position.
Another reason I don't like key switches is that they fail regularly, and if you kill the engine with the mixture, the mags can still be hot and you wouldn't know it. With toggle switches you "check" the off position of each switch each time you do a mag check. To properly check the "off" position on a key switch you must turn off the switch with the engine running.
 
Paul, You might want to rethink the subpanel. Try and get everything in the panel. Using the Dynon system you shouldn't have any trouble. That extra couple of inches below the panel takes away a lot of legroom. I fly a couple of 6s that have subpanels and I can't move my feet back off the pedals and put them flat on the floor when the other guy is flying because the subpanel hits the top of my legs. In my 7 I can do this with room to spare. It is also easier to get in and out. I have the Dynon 100and 120 in mine and had plenty of panel space. Don
 
jcoloccia said:
I didn't know that. Neat. Any idea where to buy one of those?
Click to expand...

I got mine from ACS - I prefer having a separate starter switch. I'm neutral on the key versus switch debate, but I put in a key since it might keep the honest people from fiddling with stuff....

Paul
 
HOTAS

On a tail wheel airplane, it is advisable to hold the stick full back when starting the engine. Although it may be possible to hold the stick between your legs, a more elegant solution would allow you to have one hand on the throttle and one on the stick, aka HOTAS. This would require a starter button either on the stick or throttle.
 
Paul,

Faced with limited panel space when I built the 6A, I discovered that Van's sold an oversize instrument panel. It is 2.2" deeper than the stock panel and was just the ticket to avoid fabricating a subpanel. As for keyed mag switch placement...put it wherever you feel comfortable with it. My 150 had it centered at the top of the instrument panel...I placed it low and to the extreme left on the 6A where a subpanel would be. Just sit in your cockpit, make airplane noises, think about ergonomics, and then trust your inner voice.

This time around I just might follow Mel's (always sage) advice and forego the keyed system altogether.
 
Dave Cole said:
On a tail wheel airplane, it is advisable to hold the stick full back when starting the engine. Although it may be possible to hold the stick between your legs, a more elegant solution would allow you to have one hand on the throttle and one on the stick, aka HOTAS. This would require a starter button either on the stick or throttle.
Click to expand...

As an FYI, SOP in Citabrias is:

1) Right arm across the stick (holding the stick back) and hand on the throttle.
2) Left hand runs the starter and the mixutre (on the injected models).

I wonder if Left arm across the stick and on the throttle, right hand on the starter, would work in the side-by-sides. I had meant to check this when Paul Rosales gave me ride but completely forgot.
 
Mel said:
John,
Don't depend on the ignition being off just because the key is "out". I have seen key switches that were either worn or defective that the key would come out in the "left" position.
Another reason I don't like key switches is that they fail regularly, and if you kill the engine with the mixture, the mags can still be hot and you wouldn't know it. With toggle switches you "check" the off position of each switch each time you do a mag check. To properly check the "off" position on a key switch you must turn off the switch with the engine running.
Click to expand...


OK, I know that any switch can fail and when the lock cylinder in mine gets a little sloppy I will replace it. I'm confused by the statement "To properly check the "off" position on a key switch you must turn off the switch with the engine running" Yes, just the same thing you are going to have to do to a pair of toggle switches to assure that they are grounding the mags. What is the difference?? Anyway, it is good practice to shut the engine down by turning the ignition off once and a while (at idle) to see if the switch or switches are working. There have been enough small kids and "non-swimmers" sitting in my airplane that a simple way of "locking" the mags and starter makes me feel a little safer.

John Clark ATP/CFI
RV8 N18U
KSBA
 
The difference is that every time you do a mag check with toggle switches, you are testing the off position of each one. Not so with the key switch.
 
I work in IT and a big part of my job is security. The number of 1 rule of security is that you'll never secure something 100% -- you can only discourage people.

I don't think the average pilot knows how a mag key switch works. To start the plane they would have to cut and splice some wires or take a screwdriver to the switch. For a while there was a spat of aircraft thefts around the country where teenagers stole airplanes and went for joyrides (including the 15-year old in Tampa who crashed into the Bank of America building). I believe in all of these cases they stole the keys.

Therefore, I added a key switch. Yeah, a knowledgeable person can get around it but the casual thief and the overwhelming majority of licensed pilots would be clueless. I also decided to not label the keyswitch wires to further hinder a would-be theif. If I ever have a problem I'll just have to chase them down.

A friend of mine builds hot-rods and he always has hidden kill switches on them to keep people from driving off in them. I don't think this would be a hard thing to add to RVs. You could keep the switch in the 'on' position all the time unless you were parking at an airport you weren't so sure about.

Just my 2 cents.
 
Mel said:
The difference is that every time you do a mag check with toggle switches, you are testing the off position of each one. Not so with the key switch.
Click to expand...
I think I get what you're saying Mel...with the keyswitch you're not certain that the key switch is shutting off the right mag when the left is selected and vice versa?

This actually happened with a local -7 builder (name withheld to protect the guilty). He flew his Phase I on one mag because his key switch was wired improperly. Both...left....right....both...nothing changed at all. He just thought his mags were that good.
 
Bob Nuckolls posted an excellent idea on the Aeroelectric list. Padlock one of those super duper "cutproof" chains around the propellor. That plane is going NOWHERE. You could destroy the aircraft by running the starter, I suppose, but you could also do the same thing with a hammer, a match, a handful of sand, etc, if that's their intent.
 
Actually Jamie, what I meant was that you are not checking the "off position" when you do a mag check with the key switch.
 
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Jamie said:
I think I get what you're saying Mel...with the keyswitch you're not certain that the key switch is shutting off the right mag when the left is selected and vice versa?

This actually happened with a local -7 builder (name withheld to protect the guilty). He flew his Phase I on one mag because his key switch was wired improperly. Both...left....right....both...nothing changed at all. He just thought his mags were that good.
Click to expand...

Guess I'm still missing something here. While doing a mag check with a key switch, two toggles or twisting wires together, you are going to get a drop in RPM when one mag is eliminated. If I don't get a drop in RPM I'm not going any further until I figure out why. Switch configuration has nothing to do with the test.

John Clark ATP/CFI
RV8 N18U
KSBA
 
Jamie said:
....A friend of mine builds hot-rods and he always has hidden kill switches on them to keep people from driving off in them. I don't think this would be a hard thing to add to RVs. You could keep the switch in the 'on' position all the time unless you were parking at an airport you weren't so sure about.

Just my 2 cents.
Click to expand...
As long as it failed safe (operable) I'd sure think about it. Also could use a hidden starter disable switch. Maybe a button on the floor to push with your foot!! ;)
 
John Clark said:
Guess I'm still missing something here. While doing a mag check with a key switch, two toggles or twisting wires together, you are going to get a drop in RPM when one mag is eliminated. If I don't get a drop in RPM I'm not going any further until I figure out why. Switch configuration has nothing to do with the test.

John Clark ATP/CFI
RV8 N18U
KSBA
Click to expand...
John,
When you do a mag check with toggle switches you turn off each toggle switch one at a time. Your mag drop indicates that the toggle switch actually turned off. When you do a mag check with a key switch, you never turn the key switch off, you turn it to left or right position. You are not checking the off position of the switch. This is a common position for key switches to fail.
 
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Put it down low

Back to the original question --

As already mentioned, you want the switch where it's easy to turn while you work the throttle.

But if you're thinking about putting it high on the panel, I would advise against it. Anything with lots of electrical connections -- switches, breakers, bus bars, ect -- needs to go towards the bottom. You'll understand why the first time you have to replace one while lying on your back peering through your bifocals.
 
Huh?

Mel said:
John,
When you do a mag check with toggle switches you turn off each toggle switch one at a time. Your mag drop indicates that the toggle switch actually turned off. When you do a mag check with a key switch, you never turn the key switch off, you turn it to left or right position. You are not checking the off position of the switch. This is a common position for key switches to fail.
Click to expand...

The "key switch" is just (electrically) a group of switches with a rotary selector. Two SPST and a momentary contact for the starter. You are indeed "turning the individual switch "off" (actually "on" to ground the mag) when you do a mag test. I will grant you that the switch is more complex but the current flow is the same as having a set of toggle switches. I'll say it again, if you don't get a drop with the a "off" (grounded) something isn't working properly. I really don't care if one uses a key switch or toggles the current flow is the same.

John Clark ATP/CFI
RV8 N18U (flying 200+ hrs)
KSBA
 
jcoloccia said:
I didn't know that. Neat. Any idea where to buy one of those?
Click to expand...
Try these:
http://aircraftspruce.com/catalog/elpages/igswitches.php

geico266 said:
Last year at SnF I was 100 feet from a "keyless" plane on display that started and took off full throttle jumped a ditch, crossed a busy road, and hit two parked cars. The "pilot" was uninjured, but clearly shaken up. After sitting the in cockpit a would be buyer pushed the starter button. Well, guess what, it worked.
Click to expand...
I have a push button starter on my current airplane. After building it and flying for a while I realized that if any inquisitive dufus at a fly-in so desired they could reach up to my panel and push that starter button at any time. Since it was always live even if the ignition switch was turned off it would still turn over the starter which in turn would turn the prop. This would be bad if some unsuspecting soul were looking over the engine while Mr. Dufus was reaching over to push that starter button in the cockpit. So I wired a toggle switch up with a military style switch guard over it to control the power to the starter button. If the switch guard was up the switch could be turned on and the starter button activated. If down and covered by the switch guard there would be no power to the starter button.

Again you can find these switch guards at the link below or at any other of the standard aviation parts stores:
http://aircraftspruce.com/catalog/elpages/mtllevswitches.php
 
John Clark said:
The "key switch" is just (electrically) a group of switches with a rotary selector. Two SPST and a momentary contact for the starter. You are indeed "turning the individual switch "off" (actually "on" to ground the mag) when you do a mag test. I will grant you that the switch is more complex but the current flow is the same as having a set of toggle switches. I'll say it again, if you don't get a drop with the a "off" (grounded) something isn't working properly. I really don't care if one uses a key switch or toggles the current flow is the same.

John Clark ATP/CFI
RV8 N18U (flying 200+ hrs)
KSBA
Click to expand...
OK John,
One more time then you can have it. When you do a mag check, do you turn the switch to "OFF"? If not you are NOT checking the "OFF POSITION" of the switch. Yes, you are checking the left and right positions, but not the "OFF POSITION"!
I have seen ,many key switches fail ONLY in the OFF POSITION!
 
John Clark said:
By the way, on the "double lock" issue, here is a link to the proposed legislation on the subject. It appears to be a State law in New Jersey also.

http://www.govtrack.us/congress/bill.xpd?bill=h109-3397
Click to expand...

"H.R. 3397 [109th]: General Aviation Security Act of 2005
Final Status: Introduced
This bill was proposed in a previous session of Congress. Sessions of Congress last two years, and at the end of each session all proposed bills and resolutions that haven't passed are cleared from the books. This bill never became law."

New Jersey does have a two-lock order, but it appears the order is directed to the managers of airports (Aeronatical Facility Licensees), not aircraft owners per se. Likely a way for N.J. to avoid a sword fight with the FAA, since a state can't regulate aircraft, but they can regulate airport licenses.

=============================================

The nice thing about aircraft key locks is you can open them with pretty much any key that will fit. I've used my office file cabinet key to open the door (but not start) our club Musketeer.

I was told about an incident years ago where a Cessna pilot who kept his aircraft keys on his key ring with his car, house, work, etc. keys. While flying in turbulence, he had a sudden engine failure. The weight of the keys bouncing around had switched the ignition to off. :eek:

It will be toggle switches for me.
 
long legs

Regarding legroom, my neighbor has an RV7 with a dropped panel (about 1.5", I think) to give him enough room for the snazzy glass panel goodies. When I fly with him I have to put the seat all the way back and angle my legs to get them under the panel and keep them from contacting. I'm only 6 feet, but I have long legs. After an hour in the plane I want out. I'm going to do what ever it takes to keep my panel the standard depth. The starter switch will have to find a home up higher somewhere.
 
Got it

Mel said:
OK John,
One more time then you can have it. When you do a mag check, do you turn the switch to "OFF"? If not you are NOT checking the "OFF POSITION" of the switch. Yes, you are checking the left and right positions, but not the "OFF POSITION"!
I have seen ,many key switches fail ONLY in the OFF POSITION!
Click to expand...

Mel, I do see your point now, but I thought I covered that back in post #28 with Anyway, it is good practice to shut the engine down by turning the ignition off once and a while (at idle) to see if the switch or switches are working.

"What we have here is... failure to communicate" :) (Cool Hand Luke, 1967)

Cheers,
John Clark ATP/CFI
RV8 N18U
KSBA
 
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