Tim's Panel Design and Layout Theories

Having read this disclaimer: "For the record let me state that I don't consider myself an "expert" at panel layout.  That said, I did accept a lot of advice from some who are true experts, and through feedback and tips from others I feel I have learned a lot that may be good to share." feel free to continue on, accepting or discarding information as you build your own conclusions...

In trying to come up with a panel layout for the RV-10, I tried to learn and study panel layouts as much as I could, and analyze placement of items for not only good asthetics (symmetry and balance mean very little in panel design) but good, and especially SAFE function.  You will very quickly see that even the panels from panel makers sometimes become completely ineffective designs, some with some very negative safety consequences, and that is because they will build them just how the builder wishes.  When building an airframe, the general airfame kit is very much standardized. You can do a few things to make it unsafe, but in general you've got a solid framework.  When designing a panel, you're given a flat sheet of aluminum or a fancy fiberglass molded part with some aluminum inserts, and you're allowed to go to town and place anything you want, anywhere you want.  Not taking the time to think deeply about what exactly you are doing will have consequences in functionality, safety, and resale.  Here I'll try to provide as many tips as possible to help you at least develop the thinking points, and give some conceptual info that may prove worthy of at least some thought, even if you don't find it agreeable.

Additionally, a general assumption is made on this page, and that is that the builder will be using an EFIS product of some sort, and not just a set of round gauges.  If you're using round steam gauges, I'd start by duplicating one of the old production planes that has worked well for thousands of people for many years.

Choose one EFIS system as the heart of the panel
Multiple EFIS Screen Placement
Backup Gauges
Large, Small, or Medium sized Glass?
Analyze where your hands are when placing switches
The EIS and it's place in the panel
Radio and Avionics Stack Placement
What about the Whiskey Compass?
Breaker Layout Considerations
Trim Switches and Indicators
Avionics Master or not?
What goes on your stick?
Entertainment Devices
Curvy Custom Panels
Get your Ticket!
Integrated Wx to your EFIS, or portable Wx?
Integrated Traffic, and TIS vs. ADS-B vs. Active Traffic


Choose one EFIS system as the heart of the panel
Independent of your choice of actual equipment, which this page is not going to get into directly, is the layout of your EFIS.  Today most EFIS systems can display Attitude, Navigation, and Engine data, on either single screens, or split screens.  I feel it is best to choose ONE EFIS system as the heart of your panel, and distribute it as appropriate for your goals.  What I mean by this is, if you pick a Grand Rapids EFIS, then use that Grand Rapids EFIS as effectively as possible and place it where it is needed.  Don't try to add a 2-screen Grand Rapids system, and then add a Advance Flight Systems 3500 screen, or a Blue Mountain system with an equally large screen and stick that on the panel in prime real-estate too.   The reason?  You may view it as "backup", but backup gauges are secondary to a well-operating EFIS system.  You want to consider your main EFIS as reliable enough for all of your use, yet plan for backup in the event of a failure.  This is hard to describe without a scenario, so here goes:

You take a 2-screen Chelton system, and decide that you shouldn't trust your EFIS so you also buy a 1 or 2 screen Grand Rapids System.   Yeah, that's a great backup system, with it's own AHRS, but...    Now when you enter waypoints on the Chelton, your expensive Grand Rapids system is sitting over there stupid about the fact that there's a loaded flight plan.  To effectively use it as backup, you'll need to load your waypoints there too.  Then, you've got one set of engine probes (really, nobody in their right mind would try to duplicate engine probes), and so you have an EIS.  In this example, we'll use the GRT EIS, since that would be a natural and inexpensive integration to a Chelton or GRT system. So you wire your EIS into your Chelton to feed it's engine info, and to the Grand Rapids to feed it's engine info.  But now, you're still one single wire away from an entire loss of engine data.  The only thing keeping it workable is the fact that you hopefully mounted that ugly EIS on your panel somewhere, and you could flip through the barely legible pages of data and read that if you had to.  So you're EIS may be a "backup" on it's own, but feeding it to 2 systems gives you nothing special.  Also, now that you have your 2 brands of EFIS mounted in the plane, you're going to want your favorite one near the pilot...and that means both screens, or the main screen (depends on what you bought).  So you've just stuck your co-pilot with a glass panel that doesn't do much of anything constructively, as it doesn't show them your flight plan until you or they load it, and it just acts as a plain attitude indicator.  Even the map just shows the plane's orientation until someone takes the time to enter the waypoints there.
Additionally, although 2 EFIS's could feed your autopilot with a switched input, it still relies on identical flight plan data being entered, and if flying "direct-to" from some airborne random start, you may find the courses aren't even synchronized.  Also, think ALTIMETER setting...you're flying along x/c and ATC hands you off and gives you a new altimeter setting...so you enter it on your EFIS, and your autopilot adjusts the altitude of flight.....but, what about your secondary system....that system, in use by the co-pilot perhaps, now has the old altimeter and as far as they're concerned you're now off target altitude.  Can you say "Possible altitude violation coming??"  Remember, you would have to keep ALL altimeter devices in sync for them to be accurate...even your TruTrak Sorcerer which has it's own altimeter.   In this scenario you're far better off giving yourself or your co-pilot a 3rd screen from your primary system, and keeping all of that data in sync.  It doesn't matter which brand of EFIS you're talking about, because most of them have a data bus that allows them to share data, and you'll find it much more useful to have that data passed between screens for everyone.

I'll interject my own experience here with my Chelton system...  With 3 screens, it allows any information to be displayed on any screen and it all passes to the other screen.  You enter the altimeter, or a waypoint, and my PFD, my Co-Pilots PFD or MFD, and my center MFD all carry the same data set.  Now THAT makes for an effective HEART of the system.  So pick a main system of whatever brand, and use it to the best of your layout and financial capabilities, because it is THAT system that you'll be spending a majority of your time with. You deal with your backup issues with your electrical distribution system, not by mounting a whole separate redundant EFIS system with all the similar features. Personally, that's why I went with a 3rd Chelton screen instead of spending a little less and getting the absolutely beautiful AFS Engine monitors.  If I had done that, it would have been great for engines, but it wouldn't have allowed me to spread and exchange the data as nicely, and although some can now feed the Chelton with engine data so I could display engine gauges on my closer center screen, it would have restricted my ability to display a completely synchronized MFD or PFD on that box for use by the Co-Pilot.  That, and if it were an EIS only, it takes up a lot of real-estate for just a static EIS.

Regarding split-screening engine data with attitude data, my personal opinion is that this is best left to the large glass systems if you're going to do it.  The PFD (Primary Flight Display) on most systems will be most effective if you let it remain as a full-screen attitude display.  Any engine or other warnings will likely be displayed as flags on the PFD anyway.  You don't find the high end professional gear doing lots of split-screening (with some only minor exceptions), it's something that became popular with the el'cheapo homebuilders who demanded more function in the same box. There's a reason why pro systems keep critical data clean and easy to read without split-screening.  Again, if you have a large glass panel, like 10" screens, this doesn't necessary apply to you, as that's the only way to get all that stuff effectively displayed.  But, you'll notice that the pro systems in those cases will segregate the information from each other well.

One other side note.  Depending on which EFIS you go with, putting in that fancy MX-20 or GMX-200 might prove to be the wrong way to go. They're expensive, and less integrated as above, and systems like Chelton, Grand Rapids, OP Tech, and others will all have many MFD functions. Know WHY you are considering this and research whether your objectives can be met with the primary choice first. This can allow you to get MFD features without buying an expensive stand-alone MFD product.  It was one of the major factors in getting me to choose the EFIS I did, because I actually saved money on the pricey-featured MX-20 and just redirected those feature dollars to my more integrated EFIS choice. With things like XM weather available on the GRT, it can make it more affordably effective.  For me personally I also wanted TIS info on my MFD (and I got it on my PFD too), so consider that in your choice as well as you can find more integrated ways to display TIS with some EFIS's.

Multiple EFIS Screen Placement
So now you thought about the above and decided "Yeah, I'm going to get X number of screens and keep it integrated."  but where do yo place them on the panel?   This may depend on many factors...the system you chose, if you're going to have a co-pilot helper or not, how many screens you decided to go with, and what features you have for your MFD, such as weather and Traffic.

First and foremost you need to choose a PFD location where you will spend a majority of your attention.  You want the PFD mounted as high on the panel as possible.  Any excessive down-looking can add to spatial disorientation in IFR conditions, and it can make it harder for VFR pilots to keep their eyes outside the cockpit.  Yes, the RV-10 has a pair of ribs centered with the pilot and co-pilot that support the glareshield, and yes, they come with a warning not to cut them.  But, you'll need to use your own judgment on what you want to do here.  A very large percentage of RV's flying have these ribs and have shortened them in height and reinforced them, to allow instruments to fit under them.  Once you do that, you'll be able to mount your glass nice and high on the panel, right in front of the pilot....and this I believe is what you would want, regardless of the EFIS you choose.  Consider a variable gradient scale of vision.  100% clarity is only possible straight ahead through the glare screen. Anything that is out of that straight-ahead focus will cause you to lose that ability to sub-conscienciously process that scanned data, and therefore you should avoid placing critical things more than 10 degrees up or down from that central area of vision. Only lesser-scanned or monitored items can afford to be below that eye scan area, such as fuel tank changes, climate control changes, lighting changes, etc.  Keep the more common functions in the sweet spot. When you look at airliners, things like pressurization, fire suppression, emergency lighting, and non-essentials are all relegated to the high overhead location where they are out of normal scan.  Yeah, they have their FIS system between the seats, but that data is loaded before the flight begins.  Everything should be intuitive, and don't waste the white space in your panel layout.  Everything should be well-thought out and have solid reasons for it's placement. Build your panel to keep your eyes out of the cockpit and straight ahead.  If you can't reach for it without stretching and within one second then it should be a secondary or tertiary item, not a primary function. DVD movies and things of that nature should be avoided in the panel to prevent distraction, or at minimum should not be active during IMC flight.

Once you have your PFD located front-top-center on the primary pilots side of the panel, you have to locate your add-on screens.  This will vary from system to system, and from airplane to airplane as to what may be ideal.  If you have a 2-large-screen EFIS, and only one flying pilot, you would want them both very near the pilot, but the large screens become a bit more troublesome if you're someone like me who enjoys letting a co-pilot participate fully in the flight and navigation.   That's one of my reasons for preferring smaller screens to larger...the ability to place them more strategically for multiple flying pilots.  Remember that single-pilot IFR is about as hard as it gets, and if you have people you can trust to help with the task, having them assist and providing them a PFD/MFD type display could be very useful.  If you're using one of the many medium sized EFIS's though you have a lot of flexibility.

Over/Under or Side-by-Side:  Prior to building and flying my current panel, I had thought that over/under was a the way to go.  I had seen airliners with over/under displays, and was used to the old 6-pack T config where you have the attitude display above the DG.  I was scared to break that concept.  I can't say enough though how well a side-by-side configuration works in the RV-10.  Using a side-by-side config, it's easy to fit 3 screens and a radio stack into the RV-10 panel.  Additionally, after having taken a similarly equipped plane that used over/under configuration, I found that it wasn't nearly as comfortable for me to manage as side-by-side was.  The glareshield does indeed shield screens from glare.  If you do an over/under arrangement, the lower screen will be much more affected by sunlight than a high-mounted side-by-side system.  So now I have a clear preference.  The scan is very simple too, and it's much easier to look sideways without affecting your orientation while IFR than it is to look down.  You want as much heads-up time as you can get, for VFR and especially IFR flight.

If you're only going with 1 MFD screen, you need to make some hard decisions.  Placing it right next to the PFD will be an excellent location for in-flight management of your MFD,  You will be using your MFD far more than you will be using your radio stack.  How many times will you change your transponder setting?  RARELY.  Frequency changes are perhaps often, but in the RV-10 a "Right of center" radio stack is very reachable for a pilot.  Your audio panel above a radio stack is also a very easy reach for both a pilot or co-pilot, and it also is rarely touched in our plane....with the exception of the PILOT/CREW/ISOLATE button, which we use constantly to get rid of added squeaky kid noises coming from the rear seats.  A right-of-center radio stack works very well for this.  Additionally, that isolate button is more often pushed by my co-pilot than myself.  But if you have only 1 MFD, you're in a bit of a pinch depending on your goals.  There is probably no more ideal place for it than next to the PFD, but if you have a flying co-pilot, you would do well to give them that flight info too.  Sure, they can use the MFD screen from where they are and it would be reachable just fine.  But it isn't ideal for them to fly by it.  And, you don't want the PFD display there too often, as then it's not in the best of positions for the pilot.  If you're almost always going to hog those controls for yourself, and you have a non-flying partner or co-pilot, then perhaps a total of 2 screens will work fine, hoarded on your side of the panel. Having a 2-screen system though and trying to place one on each panel half, and center the stack, will prove far from ideal.  That far screen, although very readable for the pilot, will be even further Right than the "just barely right-of-center" radio stack concept just mentioned above.  To the pilot, that means that without a bunch of reaching, an EFIS centered on the co-pilot side is just not very functional from a button pushing perspective.  At WORST you would want to consider a remote screen mode switch for that screen, because you aren't going to want to reach over in flight, especially IFR, to play with the screen mode or other buttons.

That's what leads you down the path of a 3rd screen. You get all the benefits.  2 screens side-by-side for the pilot...with the MFD very clearly visible for the co-pilot, and with it's right edge very near panel-center, it's plenty accessible to them.  Your radio stack can be very accessible to the pilot as well, as it's left edge is very near panel-center...the small 3/4" or 1" gap between them is just enough to allow you to ignore that center rib, as well, leaving your windshield support tube and everything that goes with it, fully intact.  You, as the pilot, now have full and easy access to all of the items as far over as the right side of your radio stack.  The 3rd screen gets centered on the Right side of the panel for your co-pilot, and since you were smart enough to buy the same EFIS brand as your other 2 screens, they can participate in navigation, altimeter settings, engine monitoring, weather analysis, traffic analysis, flight plan entry, waypoint entry, and all of those wonderful things.  It gives them both power to help you out when you're task-loaded, and it gives them information to keep them involved in the flight.  That extra set of eyes may just catch something that you didn't.  As far as viewing that 3rd screen goes, you as the pilot will likely have a fine view of that screen...and if there is any complication it would be just when you need to do lots of button pushing on it.  In my plane, I allow the co-pilot to use that screen as needed a large portion of the time, and I have a remote-screen-mode swap button near the throttle quadrant near panel-center that allows me to flip from PFD to MFD to Engine instruments without reaching across the panel.  That's ALL the functionality I personally need, to use that panel effectively. When they're not using it, in flight it sits there idle as an EIS for monitoring engine gauges.  During startup and some takeoffs, the EIS is displayed on the center screen, giving you access to engine data within your scan, on your most critical phase of flight. Once fully airborne, you have more important things to manage, so the center screen can become your MFD.  As far as engine warnings go, any engine warnings will pop a flag up on your PFD and MFD, and in my case they will also activate a voice warning, so you will be fully aware when you have become complacent or distracted and missed seeing that creeping temperature or other engine issue forming.

If you have 4 screens, you're pretty much limited to an over/under over/under arrangement, which becomes a very large space hog, and also has the drawbacks that are involved in having that lower screen too low....washout, head-down ops, and etc...

There are a lot of things that could be done differently if you're going to treat the layout as a sole-pilot design, but from an information display point of view, having that 3rd screen is a very nice option if you can swing it.

Backup Gauges
Backup gauges are important in the all-electric EFIS panel, but you want to approach them carefully.  All manufacturers are leaving steam gauges for all-electric and EFIS panel designs, so consider the impact on resale of a certified aircraft today.

First, remember, they're BACKUP gauges.  That doesn't mean you want to invest in a whole additional system that doesn't tie in to the rest of your panel, and it doesn't mean they deserve the same high-value real estate as your primaries.  Old planes didn't have backup gauges, they had independent instruments, so if one failed you had to know how to recognize it and use the remaining ones.  "Partial Panel".  Your goal with backup gauges is NOT to duplicate the entire system, even if the concept sounds tempting.  Your goal is to give yourself as much critically useful information as possible in an effective way to back-up an all-electric, computerized, software-or-hardware-failure-prone system.  Trying to put in a "Backup" large EFIS will just waste your precious space and retract from how functional that extra system will be.

Next, you need to purchase a system that you trust, and install it using a well-thought out electrical design, so you don't HAVE as much of a chance of failure in the first plane.  If you do that, you will find that you will rarely, if ever, have the opportunity to actually NEED your backup gauges.  People sometimes get so very wrapped up in their backups that they eat away at how effective their panel as a whole becomes.

My preference is for as much non-electrics for backups as possible, such as the mini-sized round gauges.  You don't need to waste the space on standard sized rounds for backups.  Panel space is hard to come by when you place things where they really should be.  Backups (with some exceptions) should be in full easy view of the pilot, because if you need them, you REALLY need them.  Sticking a set of round gauges on the far side of your panel isn't effective backup.  You also do NOT need to back-up every single function.  A VSI, for instance, is a waste of space as a backup gauge. A handheld, or tablet PC GPS would make a great backup GPS because it runs on it's own battery source.  On a layout note, some may notice I seem to contradict myself in my own compass location for backup.  My compass is about as far opposite on the panel as you can get.  This was intentional.  A panel-mounted compass isn't fantastically accurate in the first place.  It's there for rough heading measurements, and to meet legal requirements for a compass (AND don't forget, a compass card).   If you have a handheld GPS, an ADI with internal battery and track information, or even an autopilot like the DFII that has a built-in heading indication, the compass wil be a rarely used item.  My round gauges are limited to Attitude, Airspeed, and Altimeter, with a compass and GPS backup, and my #2 Nav/Com/GPS has it's own CDI.  If GPS is available, I can fly an entire set of approaches with those backups.  Even with just a #2 Nav/Com, I could fly an ILS if necessary.  But remember, if you are really in the soup and stuff fails, your primary job will to be keeping the airplane level and on-heading while you ASK FOR HELP and get vectors and as much info as possible.

If you decide you want to go electric, that still can be a fine way to go.  A small Dynon or similar system stuck in a good location can be a fine backup.  In fact, it could give you more info than the above round gauges.  Make sure whatever you use, it's got an internal battery backup if possible.  The only drawback to a mini-screen device like this is that it's hard to locate them in an ideal location without sacrificing some placement of your primary EFIS system.  Round gauges fit nicely next to, or underneath a PFD.  A mini-EFIS may need a more involved bit of work trying to come up with a place it fits.   Keep in mind that wherever you locate it, it's a BACKUP and you hope you hardly care to look at it in normal flight.  You want to ensure the PRIMARY gear is quick and effective to use.

Large, Small, or Medium sized Glass?
This question is one that really cannot be answered without some personal preference.  Small, as in very small glass panels like the original Dynon are much smaller than need be considered primary instruments today.  Given the low price of some of the 6-7" size LCD systems, there is no reason not to go to them for primary instrumentation.  The real complication comes with the choice between medium (I'll define it as 6-8") and Large (8" and up) EFIS systems.  Nits and lumens can be important, along with a screens reflective qualities.  Try not to compromise on products with lower quality, brightness, or glare effects if at all possible.

The Large screens give you tons of information, all in 2 screens, and most of them have excellent display qualities.  They make it easy to put all of the flight-necessary information right in front of the pilot in a very tight grouping.  That is a positive.  It also can have negatives depending on your preference or how often you have a co-pilot aboard.  If you have 2 large screens, you will not get as much ease of use out of them if you simply center one on each side of the panel.  That would be the way to make more effective use out of your co-pilot, but it detracts from your ability to have all of the high-button-pushing stuff right in front of you.  It also will require more panel space vertically, which can mean that the screens will be subject to more sunlight glare, and will mean that some of the information you're using as primary information may require that head-down scan to view it.  The other negative is that in turbulence, if you have a tightly clustered system, there large panel systems often put lots of buttons very near each other, especially between the screens.  This can make it easy to bump things inadvertently in flight.  Additionally, if you try to display such a huge amount of data, like attitude data, navigation/map data, frequency data, engine data, and everything else (sometimes even charts) all on one screen, it can make for a very busy display of information. There are also many planes flying successfully with these arrangements, but this is just some of the things to think about.

The Medium sized screens have the positives of things like being able to keep all of your critical attitude/airspeed/heading and such flight data on a single screen for a very focused main scan.  Then on the MFD, you can have a whole separate display of data for navigation...the stuff you look at less often, but use heavily for the actual navigation of your route and viewing of your navaids.  You don't scan this screen nearly as often as a PFD, because your PFD contains all of the critical information that you'd plan to scan, including distance to waypoints and cross track information.  Why do you think they call it a PRIMARY FLIGHT DISPLAY?   Then, you display engine instrumentation on either the same display as your MFD, or on a 3rd display.   Having 2 will mean more screen mode flips. (A single button push will change a display from MFD Map to MFD Engine instruments).  (Keep in mind that engine annunciations will display as flags on the MFD and PFD, and that the engine data is being sourced from another engine computer which probably also has a less pretty, or perhaps only less sizeable, display)  There are many possible modes, like a flight-plan mode where it lists all flight legs with fuel and timing data, a datalink mode for long-range weather analysis and textual information such as TAF's, METAR's, Airmets, and Sigmets, a HSI mode that although can be very nice, is actually not quite as often-used now with the amount of information you can get on your PFD and Map page.   It can be a positive thing from an instrument locating point of view in that now you have an integrated system that allows you to have cleanly readable displays and easily place them on the panel so you have 2 screens near the pilot, and 1 screen somewhere slightly further.  This leaves that screen useable, but since you have all of your most critical information near the pilot you don't have to manipulate that further screen as often.  In no case would you want to locate 2 of the medium sized EFIS screens with one on each side of the panel.  There is too much manipulation you would want to do with 2 screens, and having only one per side will make your workflow very very complicated, even moreso than the large screen systems above.  Your decision to locate a screen on the far side of the panel would be done AFTER ensuring you have 2 displays on your side of the panel.  The 3rd screens are perfect for co-pilot use, and for the information such as constant display of engine info when you don't have a co-pilot...all that stuff that you look at much less often.  The 3rd screen also allows you to save money on a graphical engine monitor, as the Grand Rapids EIS with all probes for a 6-cylinder system is only $1600 and yet can display the info on your EFIS.  It is the savings on things like engine monitors and Autopilots, and separate-box non-integrated MFD's for things like WX that allows you to move that money into a more effective 3rd screen on your panel.  

On the RV-10, a medium or larger sized screen will be pilot-visible anywhere on the panel.  Pilot-manipulate-able is another thing.  That's why you don't want to limit yourself by taking a 2 screen system of any sized screen and just put one on each side of the panel.

Analyze where your hands are when placing switches

When placing switches, always take into account things like how often you use them, or how critical they are when you use them.  I can give a couple of examples to illustrate, using my panel.

Fuel Boost:  Located directly above the throttle quadrant, positioned for an easy thumb-flick to activate it.  Why?  During takeoff or times of flight when you actually need that boost pump, you'll have your hands on or near the throttle.  If you are climbing out, you have your hand on the throttle, and if you get engine surges or power losses, you'll want quick access to that switch.  I also placed an indicator next to it so you don't forget to turn OFF that pump, which is also important.

Flaps:  Again, during go-around or takeoff, you may want to readily retract flaps, so locate them by your throttle quadrant for easy access.  Additionally, your primary use of flaps is during landing and that is also a time when you constantly have your hand on the throttle.

Master/ALT/E-Bus/Aux Bus switches:  These are used only once or twice per flight maximum, so they don't deserve prime real-estate, but they do deserve some stand-out identification.  Making sure these types of switches are easily identifiable is your main concern.

Autopilot On/Off and Source Select:  The On/Off switch should be located right near the autopilot.  If you have any signs of a runaway autopilot, you want this thing able to be disconnected immediately.  The source select (mine selects between the EFIS and the GNS-480) should be located near it as well for logical function.

The other switches (Below) - Most of these you can put in most any location, but for the most part they don't need to be co-pilot easily accessible, just pilot accessible.  They drive non-critical functions, or seldom switched functions.

Pitot Heat:  This switch is seldom used, and even when going full IFR, it is nothing major to locate your switch and turn it on.

Lighting:  The concern with lighting switches is to make them identifiable so if you need to activate them in darkness you can find them.  Carefully separating them into a section from your other misc. switches can help, as can using different sized or shaped toggles.  Dimmers should be located near light switches.

Other notes on switches:  Breaker/switches can be used on some items if desired, to save on breaker counts.  3-position switches can do some creative things, as can double-pole switches. Mini-toggles can be used for some functions, like Autopilot source select.  Avoid placing any switches directly in front of your stick.  Even the Van's Standard RV-10 panel will have that lower panel brace be hit by the stick.  You don't want broken switches or inadvertently activated switches from a forward moved stick...which happens commonly on the ground.

One special switch: If you have trim available on your sticks, you may have times when you want to disable the co-pilot stick from being able to operate the trim.  That prevents kids or non-pilots or non-careful passengers from inadvertent trim operation.  It's easily done by disconnecting the grounds.  The RV-10 has a very quickly operating trim in high-speed cruise, so this switch is a must for some people.  Locate this switch somewhere on the panel where you can reach it quickly, but you may want to locate it where the co-pilot can also reach it if desired.  As a general rule: never place more than five switches in a row before you break the flow into sub-functions.  Logically locate them where they can be activated/de-activated while you are blind-folded.

Don't forget to add a dimmer or rheostat control to any lighted switches, as it doesn't take much from an LED or light to over-power your night vision.

The EIS and it's place in the panel

First, let me say I'm not discounting the value of engine information.  Quickly idenfiying engine issues is critical to safe flight. With that said, it still isn't the most critical information in the panel, your PFD info is.

The EIS should be displayed or displayable in a readable location that is easy to see when required.  I add "when required" because of a few points.  EIS warnings should annunciate lights, and add flags to your PFD/MFD. On my system, an engine warning will also make a voice callout, and may actually auto switch an MFD screen and highlight and flash the offending engine limit being exceeded.  Additionally, as mentioned above, most EFIS systems are driven by an external EIS.  This being the case, you can easily locate a small box, like either the ugly GRT EIS 6000, or the nicer looking MVP-50 or Advanced Flight Systems mini engine monitor.   Those boxes would serve as your permanent display of engine data, while your screens would be configured either as split screen or EIS screen, as needed.

On an additional note, the ability to constantly display, and move around from screen 2 to screen 3 as needed, was one of my larger selling points for getting a 3rd screen.  In flight, I use the engine instruments on all non-Low-IFR takeoffs on my screen 2, and then move it to screen 3 before I enter IMC.  Also, during cruise after leaning, I allow that 3rd screen to be used for other functions as needed, as once your temps and everything are stabilized you can reduce your scan frequency of those systems....providing you have proper limits set up for alarms.  I'm not saying you stop scanning, but you scan less often.

First, provide for your most critical information, then provide for your engine data.

Radio and Avionics Stack Placement
In the old days, the radio stack was just placed slightly right-of-center on the panel, to allow for the mass of steam gauges.  Many panels had spare space on the Right side with nothing in it.  Then, if the stack was full and you wanted to add something fancy like an ADF or a DME, you could add some holes on the far right side of the panel.  Today it's a whole different ball game in some respects.  You don't have as many items or as much space taken up as in the past, except for in the cases of large radios like the GNS-530.  A 430/480 takes up less or the same space as an old King KX-170B.  This allows many or most builders to have everything you need in one stack.

One thing that is curious that I see sometimes is panels that place radios and transponders all over the panel, perhaps under the EFIS screens, along the lower side of the panel.  While it might seem like you can fill some good wasted space, I'm still much more inclined to stick with the old standard right-of-center stack, and here's why.   You give up real-estate that has much better uses. As discussed above, your backup primary flight instruments deserve some near-prime real estate, such as below your PFD.  Your Autopilot is a device you will want to have very ready access to in the panel also.  Definitely not something to put way off on a panel edge somewhere.  Once you buy in to those types of things, you start to limit yourself as to where you'll actually have available for radios.

The fact is, if you stick your radio stack to the immediate Right of the center rib, your radios will be very visible and very accessible to both the pilot and co-pilot.  Just what you'd want out of your Nav/Com radios.   Center stacks are OK, if you can accomplish the best intended goals of mounting your PFD/MFD for pilot use, but you not only have to try to fit the stack under the windshield support tube bracket near the sub panel, but you may have to make concessions in how you place your PFD and MFD....something that you shouldn't do without serious consideration.

Some of this may also depend on which EFIS you purchase, but I'll point out one thing.  Garmin, in their GNS-480 manual, actually specifies how far from center of your PFD you are allowed to put the GNS-480 in certified installations without adding some sort of external annunciation.  This does illustrate that even for a radio they do care how accessible and visible it is.  Again though, in the RV-10 there isn't any panel space other than the very far Right that would not be visible for an EFIS screen, and a right-of-center radio stack is extremely functional and accessible in the RV-10.

Additionally, for some EFIS systems you will not require a device like a 430/480/530 to be your primary navigator, and therefore you have to weigh that into your placement as well. If you're going to be using a GPS/Nav/Com constantly as your main navigator, you will want it very accessible to the pilot and the co-pilot.

This is a good time to point out the value of printing full-size color cutouts of your panel instrument choices and making a cardboard panel...and then actually sitting behind it and reaching for every knob and switch....all before you purchase any of it.  Paper cutout tests are way cheaper than building a panel and finding out later.

What about the Whiskey Compass?

I've found a panel mounted compass to be largely error prone with electronics and busses nearby.  If you truly want an accurate compass, get some remotely sensed version with a sensor in the wing somewhere, or mount a vertical card compass on the windshield post, even though they don't really count as highly accurate.  Although compass headings are important to have while flying on backup gauges, if you have a reasonably aligned compass and are talking to ATC in a radar environment, they can help you with vectors and you'll be using your compass as more of a rough tool to hold an approximate heading.  A handheld GPS if the GPS system is operational, would do a far better job giving track information. So in my personal opinion, if you're going to relegate something to the far nether regions of your panel, the compass might be a good one to put there.  Just make sure it's readable to the pilot.  Remember that you are required to have a standard compass for IFR flight. I have heard SIRS makes a great panel or free-standing unit.

Breaker Layout Considerations
When installing breakers, location is down the list a ways as to how critical that space is.  Use your good space for your PFD/MFD/Co-pilot as best you can, and use some left-over space for the breakers.  When labeling them, if you have multiple busses, try to outline the breakers with trim lines so you can quickly identify which breakers are on which bus.  As far as breaker use goes, use a breaker on ANYTHING you may want to disconnect power from in flight. This ABSOLUTELY includes any item that has control over your flight controls.  All of the main radios, and those sorts of things, have a breaker in my panel, and especially the trim, and flaps.  

If you run out of space for breakers, switch-breakers are great options for things like pitot heat, landing lights, and such. That gets rid of a breaker and puts the control right on the switch.

Trim Switches and Indicators
I've found that elevator trim is absolutely best done on the stick itself.  You can add a panel switch if you want, but even though I have one, I have only used it about 2 times, and that was just for verification that it worked, and demonstration.  An aileron trim switch works great on the stick. You don't use it often, but when you need it, it's nice to have.  Also, having it on the stick lets you test aileron feel by releasing stick pressure as you trim.  A rudder you trim by looking at the ball, and that would be done more in cruise, so that makes a good switch to locate on the panel...perhaps near the center by the throttle quadrant, so as you finish leaning and setting power for cruise, you can trim out the rudder.

Trim indicators if you use the LED's from Ray Allen, are visible anywhere in the panel you put them, so try to fit them in some good spare space as you complete the panel layout, but don't be concerned if that space is far away from the pilot.  I wouldn't bother putting them in the directly pilot centered area.  You can go a whole flight and never look at the trim indicators any more than to set the initial elevator trim for takeoff.

Avionics Master or not?

This one gets people really charged up on the Aeroelectric-list.  Personally, I chose to have an Avionics master to allow everything (kind of) to be turned off from one switch.  The exception is that I also have an E-Bus so my E-Bus is on during cranking with my aux battery powering my PFD/MFD/NAV1/COM1/Autopilot/EIS.  So I have full access to engine data, and any downlinked weather, and communications to file and activate plans before I crank the engine.  Also, in my arrangement, once the avionics bus is on, my other instruments boot, any my e-bus can be off and feed the e-bus items from the avionics bus.  I can also back-feed the avionics bus from my e-bus, but only when the e-bus switch is off, so I do still have some coverage over a single-point-of-failure and I don't have to worry as much.  In short, depending on what you do with our bus, you may or may not worry so much about that avionics master as a single point of failure.   What you do not need, is a power switch for every EFIS screen.  As long as they're on an aux battery so they don't drop during cranking, you have no concern with powering them on and off during flight.  Breakers do that real well if you really need that functionality on an occasional basis.

Of course, if you're totally against an Avionics Master, just don't use one.  But be sure to thoroughly think through what will happen during different situations like engine cranking, battery failure, alternator failure, e-bus usage, and so on.

What goes on your stick?
This is somewhat open to personal preference, and it's also a topic that highly charges some builders. Personally, I feel you are best excluding from your stick, ANYTHING other than trim that affects flight controls.  I.E. Don't put flaps or speed brakes on your stick because accidentally deployment can have big effects on your flight.  Both speed brakes and flaps have a great place to locate them....right near your throttle, because for times when you would manipulate either of them, you'd probably also be making power changes as well.

Another thing that some people buy into that I really cannot see as being a good idea is a start switch on the stick.  There is no good reason in most airplanes that you can't crank the engine from a panel mounted switch or key, and hold the stick with your knees.  Besides that, do you really want a button that is used only once per flight on your stick?

It comes right down to "valuable real-estate" again, and things that you would do commonly being on the stick.  Aileron/Elevator trim is almost a must. Push-to-talk is a must.  A MUTE switch for EFIS Voice warnings is one that I absolutely see as essential, after over 225 hours of flying with it.  An AUTOPILOT DISCONNECT is a 100% requirement for your stick, and that one I would not back down from in any fight.  Now, even on the well-equipped infinity stick grip, you're left with 2 more locations and THAT'S IT.   If you fly Left-hand on the stick, don't place any switch used in flight where the hands must change the stick or reach over it to activate/de-activate a switch.  Make it logical. So, here is where I look for those last 2 items:

Com Flip-Flop:  You can either tie this to a Nav/Com (or two), or to the audio panel.  I chose to tie it to my COM1 and my COM2.  I used a 3 position momentary switch, and if you push it up,  you flip-flop Com1, and down will flip-flop Com2.  This makes this scenario possible:  Doing an approach you get cleared for the approach and frequency change to the local Unicom.  Hit INFO on the EFIS, an hit ENTER as it has your airport fix in it already.  A list of items comes up for scrolling where you can get runway lengths, current winds and weather, and all frequencies.  Just scroll down to the Unicom, hit "TO COM" and it will load that frequency in the radio's standby location.  You're doing this with your Right hand.  Your Left is still on the stick.  With it loaded in standby, a flick of the thumb and you've got it activated, even without touching your radio.  For COM2, you can't perhaps auto-tune, but you can still get the benefits of flip-flop if you preload your frequencies.

EFIS Screen Mode Change: With almost any EFIS system...at least the ones with lots of MFD capability, you will have way more screen modes than you can make use of simultaneously.  A mode change button on my system allows me to keep my hand on the stick and cycle my center screen between PFD display, Map page (or HSI), and Engine instruments.  It makes for a very convenient way to check things like power settings, on the spur of the moment, even when your co-pilot is busy looking at a big datalink weather picture for instance, and then you can return back to your map page and keep monitoring your progress.

There are other useful things you could consider putting on your stick, but consider the limited value of some items, like IDENT, that you do perhaps one or two times on an IFR flight, and lights of any type, that are perhaps best just left on the panel.  A good stick plan starts with putting the things that are critical for your system on the stick, and then making the best possible use out of that last button or two.

Entertainment Devices
I almost hate to make this statement as I'm sure it will disagree with some, but...  Entertainment devices (read DVD screens) have no place in the panel on an IFR panel, or at my most generous side, I would state that only in some very specific, single-pilot (no co-pilot) panels should it even be considered.  The prime real estate is far too valuable to place critical flight data, and you should plan to use it to the fullest extent possible given your equipment list.  If you end up with everything you can possibly think you'll need for safe IFR flight, and have no plans to ever have a co-pilot flying, then sure, stick it over on the far side of the panel after testing to make sure it has absolutely no interference with your avionics...but if you plan to have a co-pilot, let them be entertained by either handheld portables, or by the sheer enjoyment and learning experience of flight and navigation.   If you're building a VFR-only plane you may get more leeway in that statement.

Curvy Custom Panels
I have found the Van's standard aluminum panel to be a very workable system for instrument placement.  There are a large variety of great looking and also functional fiberglass panels out there.  Remember to think about all of the placement issues that any panel choice will cause, before you actually order one of the non-standard panels.  This doesn't mean you shouldn't get them, as many are very nice.  Just make sure that all of your placement goals are NUMBER 1 in your decision process and make sure you get a panel that allows you to meet your goals. Also, regarding canted panels that are more ergonomic for the pilot:  Remember that canting a center stack or a right-side radio stack will also make it less useable to a co-pilot.  Always take into account the amount of time you may have with a co-pilot.  A spouse who's willing to help with some tasks can be a great help, and if you have the opportunity to have a true co-pilot you can find yourself far better off than flying the old "single pilot IFR".  Canting of the outer edges of the panel, to make a more rounded or visible panel may also have some positive benefits, but again, don't let that disrupt proper EFIS and instrument layout.  In some cases, canting a panel corner would cause instruments that stick out the back side too far to contact the aircraft fuselage...so lots of pre-planning is required for anything with angles in it.

Get your Ticket!
This I just can't say enough.  GET YOUR INSTRUMENT RATING A.S.A.P. if you're building an RV-10.  The insurance companies in some cases are requiring an instrument rating for some pilots, having the rating will help lower premiums, and even if you never intend to fly IFR in your life, the skills you learn will be absolutely valuable.  Additionally, you really will not have a clue as to exactly how critical some placement issues would be, and what instruments you may want, unless you have some instrument training and experience before you design your panel. If you absolutely have to build a panel without any instrument training, leave it to the pros and tell them you want them to do the best designed panel they can do for safe IFR flight. The simple mistakes you make in layout and equipment choice will have a profound impact on your resale value, and accident mistakes have an effect on all other RV-10 builders.  Choose wisely, and seek competent advice.

Integrated Wx to your EFIS, or portable Wx?
So you want to know why you would want to buy a more expensive, but integrated Wx system for your panel, instead of just buying a portable like a 396/496 and calling that good. Those units are excellent options for some people, and they do a great job, but, there is LOTS more to consider when purchasing such a system.  Here is an example, and I think that although I'm using my system as an example, it would be the same for systems such as GRT EFIS, and some others:

If you have it integrated, you're flying along, there's storm cells ahead scattered around.  You're VFR (or IFR) and you want to avoid any of them.  Your COURSE to the next waypoint is on-screen,and you can see that the pink line goes right into the area of the cell.  On the Chelton at least, your actual TRACK is also displayed on screen, and therefore you know your HEADING, your TRACK, and your COURSE...all on that same screen.  To avoid the storm, you put the EFIS, which is commanding your Autopilot into HEADING mode to avoid the cell, spin the proper heading in, and watch your TRACK change.  Nope, that didn't quite take you clear enough for comfort, so you turn your heading bug some more.  Now your track looks like it'll take you well clear.  The feedback in flight given by it's integration was very valuable. Your COURSE is still set right through the storm, and you'll adjust that later by re-initiating your position to that next waypoint, but that's done once you're around the side of the cell.  For now, you clearly can see that your current track avoids any danger.

The weather on the portable is fantastic stuff, but, if you have the opportunity to integrate it into your EFIS, you won't have to estimate and interopolate where you are tracking towards, and where the weather is, and enter courses and waypoints and keep the handheld programmed with all deviations, and things like that.  You only have one system to manage and it's much tighter in integration and less work to keep on top of it...especially nice if you're flying IFR.

Integrated Traffic, and TIS vs. ADS-B vs. Active Traffic
For the same reasons as above with integrated Wx, I think that if you have the opportunity to integrate traffic display to your EFIS, you will find it beneficial.  On the Chelton this is particularly true, because I not only get traffic with distance, climbing/descending, relative altitude, and bearing, but I get the same thing on the PFD display, which is very cool in itself.  Here are 1 and 2 screenshots.  So integrate it if you can, but HAVE it in some form if at all possible.

What about the forms, there's TIS using Mode S transponders, that's being pulled from places around the country, there's ADS-B which is growing, although slowly, and there's Active Traffic with systems like what's available from Avidyne.  Personally, I have TIS with the Garmin GTX-330.  It works in a lot of the airspace I've flown around the country, but usually only in the more traffic-concentrated areas. This hasn't been a huge limitation, as I've had coverage where it mattered most, but it's too bad that the philosophically-challenged FAA can't keep up with what they started and leave these radar stations intact and add to the amount of Mode S coverage areas.  The phase-out is a very slow process, and is projected at taking 10 years or more.  This means that as an affordable option, consisting only of adding a little more pricey transponder, you can have a pretty good system for many years. In my first 1.5 years of having it, I've found I wouldn't want to be without, and it's saved me a few potential problems already.

Moving on to ADS-B, I can't knock it a bit for value, because that's the way the FAA at least THINKS they're going, although they aren't proving it with any agressive implementation.  The problem is, the coverage areas are limited right now, and the receivers are many thousands more money than doing it with Mode S TIS.  If you have the cash, and the receivers are cheap enough, great...add ADS-B today.  Hopefully though as more ADS-B stations become installed, more manufacturers will build equipment, and at that time it will have more value.

Ideally, if you have the resources, an active system that does not rely on any of the FAA's politics to implement would be the best option.  The only downside is the price, and the ugly pair of antennas required.  The upside is, with active systems such as the Avidyne TAS600, you get great traffic coverage EVERYWHERE.  So this is a system that would be great if you have the added funds.