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Panel Layout

N941WR

Legacy Member
I recently flew an RV that was very well built, flew well, etc. However, the builder was more interested in making everything line up than worrying about switch placement and function.

For example, all the switches were standard toggle switches of the same size, lined up in a neat row with the same gap between them. Some did have colored rubber covers on them.

Right next to the master, on the left side of this side-by-side's panel, was the fuel pump switch. I could see someone accidentally turning off the master, powering down the avionics, while on approach when trying to turn on the fuel pump on a bumpy day.

The other gotcha is that hidden in that row of switches was the electric primer. Worse than accidentally turning off the master would be turning on the primer when trying to deploy the flaps because the switches were next to each other, flooding the engine.

When designing your panel, take into account what could happen, if you were to turn something on or off by mistake and don't place commonly used switches next to a flight critical swich.

I grouped my swiches by "phase of flight" and not function. Thus my interior lights are not close to my landing and taxi lights. My swiches are also laid out so for landing or takeoff, you just go down the row, turning them all on, left to right, and then put your hand on the throttle until you land. You can even toggle the flaps up and down without removing your hand from the throttle. (More details are available on my website.)

Remember, someone else may fly your plane and as an aid to them, logical switch placement is critical.
 
Hi Bill,

To each their own I suppose. I'm a control freak so I have a lot of switches. My 20 or so are switches grouped by function and separated from other groups by one switch space (in case I screwed up, there's room to add another switch if needed).

The groups (of function) are located left to right so there is some flow. But flow is never going to be exact. As a result, if I want a light, I will look to the lighting group. You really can't go too far wrong by turning on/off the wrong light.

Groups typically have odd numbers of switches so I can easily memorize their function (left, mid, right), and never more than 5 in a group. The left switch is the first or most commonly used item in the group.

Further, I have any flight critical switches with a red boot on the toggle. They are located directly in front of the left seat pilot so they are part of the left/right flow, always in view and further from the passenger. The red boot indicates caution before movement and my passenger is always instructed not to touch anything especially anything red. Other colors loosely indicate function, ie yellow = lights, blue = fuel pump (100LL is blue) etc.

Always a compromise like everything in aviation.

Bevan
 
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With the current generation of glass panels, there is always a little button-pushing going on. Consider what can happen in turbulence, I have my switch row a hair too close to the bottom of my EFIS screen and twice now in a bump I have had my hand deflect downward to contact those switches.

I'm already planning round two of my panel, that's one of the changes that will be made.
 
Also, my switch panel (which runs the entire length of the bottom of the instrument panel) is recessed about 3/4". This helps to prevent inadvertent switch operation when moving the hand about the instrument panel.

There are a lot of ways to do a panel. I just throw these out as ideas. While I spent a whole winter researching and designing the panel, and it works very well for me, I realize there are about as many ways to configure the panel as there are builders.

Bevan
 
Individual choice.
I chose to lay out the switches left to right in groups for a flow from power through avionics including pitot to lights.
As I have seen on other craft, fuel pump and flaps are near throttle so they can be activated while hand is on throttle.
 
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Although purely preference, I would argue for seeing how it's done on relatively recent production aircraft. The human factors folks there have spent a lot more time thinking about this kind of thing than most of us.
 
Although purely preference, I would argue for seeing how it's done on relatively recent production aircraft. The human factors folks there have spent a lot more time thinking about this kind of thing than most of us.

I had a human factors guy contact me after stumbling upon my website some years back. He was involved with the design of a new jet aircraft that will remain nameless. He had nothing but complements regarding my layout and the reasoning behind it. He wanted to know where I studied and learned so much about human factors and so forth.

As side note, I have seen switches scattered all over the place. Flap switches down between the seats, up on the top of the panel, just under the glair shield, you name it. On a bumpy flight, those locations can make it difficult to reach and take the correct action. Between the seats was an odd one as you will have to do it by feel.

Interior light switches next to taxi and landing lights are not a good thing because if you are coming in to land at night and flip on the interior lights instead of the landing & taxi lights you could ruin your night vision.

While we as builders and fliers learn our panels, rows and rows of intermixed switches aren't always "best practice".

What I did was mocked up my panel and kept moving things around until I was comfortable with the position of everything, including switch spacing for my big hands. On a go-around you can push the levers forward, push the carb heat in, and toggle the flaps up without removing your hand from the throttle quadrant.

The master switch, mag switches, and starter button are all in a row; master on, mags on, press the starter. In an in flight emergency, you just go right down the row, you don't need to hunt for switches or buttons.

Things the passenger can mess with, put on the right side; panel lights (not used very much) are just right of center, interior lights and cabin heat are way over on the right side. Still accessible from the left seat but out of the way.

Remember, you are designing for the worst case, high stress, situation. Not necessarily for sunny day no problem flights. The simpler and more logical you can lay our panel out the better. When in a high stress situation, one of the first things that goes is your fine motor skills. Thus placing switches close to one another that have nothing to do with primary flight situations could become an issue at the worst time.
 
I think the standard row of toggles can be very effective, provided they're not spaced too closely, the control stick doesn't hit them, etc.

To me, color coding is the key: red for master & alternator, yellow for EFIS & avionics; white for lighting functions; and blue for fuel pump. I prefer the "reds" to be a little higher, for less chance of accidental bumping. I like to fly with the the lights on all the time (except cabin lights!).

 
I'm planning to use some switch guards (the U shaped bent rod type) around my master switch and maybe others to get a reference by feel. I believe it will help, especially during night flight.
 
Strangely enough, we just cut a brand new panel for a flying airplane in a rather well known VAF'ers plane (won't post name to protect the innocent), because during some turbulence or wifferdils or something he accidentally managed to trip the ELT remote...imagine his wife's surprise when she got a call about his ELT going off!

Result....he decided to relocate the ELT to an area still accessible but not necessarily in the line of movement of his non flying hand!

As others have said, each person has their own ways of handling things, we often will offer guidance and my own famously blunt opinions, but beyond that we've made them in every imaginable scenario (including the old "load instruments/switches into a shotgun and pull the trigger approach)! :)

Cheers,
Stein
 
I had a human factors guy contact me after stumbling upon my website some years back. He was involved with the design of a new jet aircraft that will remain nameless. He had nothing but complements regarding my layout and the reasoning behind it. He wanted to know where I studied and learned so much about human factors and so forth.

As side note, I have seen switches scattered all over the place. Flap switches down between the seats, up on the top of the panel, just under the glair shield, you name it. On a bumpy flight, those locations can make it difficult to reach and take the correct action. Between the seats was an odd one as you will have to do it by feel.

Interior light switches next to taxi and landing lights are not a good thing because if you are coming in to land at night and flip on the interior lights instead of the landing & taxi lights you could ruin your night vision.

While we as builders and fliers learn our panels, rows and rows of intermixed switches aren't always "best practice".

What I did was mocked up my panel and kept moving things around until I was comfortable with the position of everything, including switch spacing for my big hands. On a go-around you can push the levers forward, push the carb heat in, and toggle the flaps up without removing your hand from the throttle quadrant.

The master switch, mag switches, and starter button are all in a row; master on, mags on, press the starter. In an in flight emergency, you just go right down the row, you don't need to hunt for switches or buttons.

Things the passenger can mess with, put on the right side; panel lights (not used very much) are just right of center, interior lights and cabin heat are way over on the right side. Still accessible from the left seat but out of the way.

Remember, you are designing for the worst case, high stress, situation. Not necessarily for sunny day no problem flights. The simpler and more logical you can lay our panel out the better. When in a high stress situation, one of the first things that goes is your fine motor skills. Thus placing switches close to one another that have nothing to do with primary flight situations could become an issue at the worst time.

Totally agree that this stuff is very important. In a stressful situation, the spatial separation is imporant. Also, for certain mission phases, such as formation flight, certain switches need to come to hand quickly.

I would add that whenever a function is OFF, the switch toggle should be down. This makes visual scanning easy. I have dual function light switches that are OFF-WIGWAG-ON. I see this done where the center is the OFF position, but that is not in keeping with down-OFF. I had to design a special flasher for this, but it was worth it for me.

My ignition switches and master switches are on the side panel, well away from everything else.

One thing I had to do is put a second trim switch on my Throttle. The hat switch on my Infinity grip works fine, but I usually fly formation with my fingertips. Repositioning my hand to activate trim leads to PIO, so hence the second switch.
 
"Down for on" seems equally bizarre to me, as it runs counter to how wall switches are set up in our homes.

When you flip on the house lights in Australia, is it down for on?
 
In many countries light switches are down for on.
As it is in Oz.
Our Boeings are down for on.
See this thread. http://www.airliners.net/aviation-forums/tech_ops/read.main/332593
My RV is down for on.
Up for on is just odd for me.
I guess thats why they should be marked on off. Mine are not . Hmmmm.

Cessna 170's 1952 and earlier had "piano" style switches that were down for on. The later models make more sense to me: push/pull switches that pull for on.
 
"Down for on" seems equally bizarre to me, as it runs counter to how wall switches are set up in our homes.

When you flip on the house lights in Australia, is it down for on?

Yes, also in NZ. Has something to do with being in the southern hemisphere, just like how the toilet cycles the opposite direction to what it does when you flush in the northern hemisphere....:D
 
often will offer guidance and my own famously blunt opinions...

Your blunt opinions end up costing me exponentially more than even those of my wife...But golly I love the warm glow of glass...

Back on track: The problem with people is that they are human; marvelously diverse. Can't make everyone happy. My switches are all tucked into the right hand 'arm' rest/cubby in my -4. It occasionally bugs me in the bumps to change stick hands to hit a switch; but that same annoyance has prevented an inadvertent action from happening. Additionally, if I need everything electronic to knock it off I can shut everything down with my forearm in one fell swoop, give or take a backup battery.

If I was building...I don't think I would change a thing. Well...maybe I'd do something to keep my back seater from stepping on my trim lever, admittedly thats gotten old...
 
A year or two ago I had a chance to glance into the cockpit of an RV8 owned by Ralph Howie of British Columbia. His cockpit featured so many different types of switches that it seemed he had purchased them in a box of "odds and sods". Turns out this was all by design. Switches with similar function were of similar shape and were grouped together. Each functional group had a different shape of switch. Ralph's design goal was to be able to reliably identify and operate each switch while blindfolded. He succeeded brilliantly in achieving his goal.

By contrast, the panel for our current project was originally built by a well-recognized professional panel shop. It uses Honeywell rocker switches, which are terrific switches, but they are all in a row, tightly spaced together. The real kicker was the avionics master was located closest to the throttle, furthest from the split master, and right beside the frequently-used landing/taxi light switches. I found this to be an extremely "user unfriendly" design and spent considerable time re-arranging switches so the boost pump is closest to the throttle, followed by landing and taxi lights, with the avionics master switch now closest to the split master, way over at the other end of the row.

I still find it difficult to believe that a reputable instrument panel builder would have arranged switches so poorly. I could just see me flying an instrument approach, hitting the landing light switch, only to see my avionics blink off as I bumped the avionics master. Dumb, dumb, dumb.
 
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I've never flown blindfolded, but in formation one must be able to locate and operate common switches without looking. In addition, it's better to have these on the grip or throttle quadrant or within a finger's reach.

Now, if I could just get Siri to do all this for me.
 
Down for on...

Down for on is standard for just about every switch on Boeing products...

Although the position and strobe switch is set up with off in the middle...
 
Yes, also in NZ. Has something to do with being in the southern hemisphere, just like how the toilet cycles the opposite direction to what it does when you flush in the northern hemisphere....:D

When I flew a military plane down to Australia, half the crew immediately went to the bathroom to test out this theory. They were completely baffled by the fact that the toilets were going the same way as they would back up north...

One of the Aussie customs guys overheard their conversation and had to set them straight. Toilets have ramps built to cause an artificial swirl... You need to test this on water draining from a resting pool, i.e. a sink.
 
Down for on is standard for just about every switch on Boeing products...

Although the position and strobe switch is set up with off in the middle...

Not to be too curmudgeonly, but I suspect the term "down" in this statement may be subject to some interpretation. If switches are located in the overhead, this denomination of "up" and "down" really gets muddy. Mix that in with a user's perspective (sitting in the pilot's chair, or reaching forward from the FE's chair) and it's amazing to see how many different interpretations one can come up with! :D

The standards document which Boeing provided in the first part of this century as a design guideline to vendors clarified this wording by stating that the preferred ON position is either "up" for a switch mounted on a vertical panel, or "forward" for a switch mounted on a non-vertical panel accessed by the flight crew (ie the overhead panel). There was also similar wording for pushbutton switches; I can't recall the exact statement but it would generally be interpreted to say that a pushbutton is intended to actuate the function when the button is depressed, thus the "pushed in" state is the desired ON state.
 
Intuition is a pretty powerful driving force. Take the flap switch....mine's a pretty standard paddle extension on a toggle switch. Up to retract, down to deploy, mimicking the physical action of the flaps themselves. Agreed, most have ours rigged that way, but you get the point. Push in the throttle for max power, just like you'd push down on a car's accelerator pedal...both move away from you for more speed. Of course, label everything for good measure and DAR satisfaction.

With a lifetime spent flipping light switches up for on, it's hard to argue with that intuition, not to mention habit and muscle memory. As it applies to lights, I also like to think of it as: sun rises (up); sun sets (down).
 
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