The instrument panel

As with so many parts of building my RV airplane, I wasn't sure I was up to the task of designing, cutting, and wiring my instrument panel. Wiring, as I've written many times, was particularly scary to me.

Last night, I finished the instrument panel.

Hard as it is to believe, I started the process two-and-a-half years ago, but that's the nature of (a) going slowly while learning what I'm doing and (b) paying as I go and (c) making changes along the way.

Here's was my final design at that time:



When you're designing a panel, it's really easy to forget a lot of the little details, so it was important to remember some of the initial advice I had received, especially in the area of not designing a panel that would preclude changes.

As it is, I sectioned the panel off into clusters. A systems cluster on the left -- the electronic flight information display, engine monitor, backup altimeter and backup airspeed indicator -- a "switch cluster" in the center -- the Vertical Power system, mag and electronic ignition switches as well as switches for flaps, boost pump and master switch -- and a "communications cluster" on the right, all within an arm's reach. This section includes the GPS, transponder, and communications radio, as well as an input under the panel for an iPod.

The wing-leveler (autopilot) and fuel gauge are tucked under the Vertical Power system.

On the far right is a "nice to have but not-necessary-to-keep-the-shiny-side up" section which includes a remote switch to activate the emergency locator beacon, a power adapter (which I'll use to power a traffic avoidance system of some sort) and a compass.

A lot of people install a map box here but I couldn't -- or at least, didn't -- because it would have meant cutting into the subpanel behind it and I would've lost this...




...the story of which you can read about here.

Oh, and way over on the left is the "keep it away from the passengers" cluster which is the starter button (actually, I put it there to (a) keep it out of the way from being accidentally hit and (b) allow me to keep my right hand on the throttle when starting) and the cable to allow the "emergency air" into the air intake of the fuel servo in the highly unlikely event the snorkel on the cowling gets plugged up in flight.

The two switches under the Vertical Power unit are for the left mag and the right electronic ignition (Lightspeed). The switches just above the throttle knob are (left to right) master switch, engine monitor power (I really didn't need this switch but it was simpler to wire it this way in order to include the red warning light),  flaps, and fuel boost pump.  The boost pump switch is powered by the Vertical Power system when flipped "up," and powered off a separate bus if I flip it down.

I like this panel a lot, partly because we've come to know each other over two years. It's the nature of the beast now that it's probably outdated even though it's never flown, but it is a functional and affordable panel.

I know a lot of people think, "an airplane you built yourself? How can that be safe?" But take a look at what one is able to do building one's own airplane? Compared to renting the factory-built Warrior II at the local airport, I'll have a traffic alert and avoidance system, better displays of airspeed and situation, an autopilot wing-leveler, immediate engine information that will alert me to problems with an engine before the big fan in the front stops turning, and a system that monitors my electrical infrastructure. That's a lot of safety right there.

I'm a VFR pilot and a lot of the big bells and whistles stuff  I don't need. Most of the information I need to fly an airplane, I actually get from looking out the window and listening at the same time.

Flying is fun like that.

Bright lights, little airplane

If nothing else, any time you can get a full instrument installed, wired, and powered up in one session of work, I think you've done OK.

Today I checked off another item on the big dry-ink board in the hangar: Install fuel level indicator.

The Electronics International fuel level indicator has two separate power wires -- one to power the instrument and one to to power the backlight, and a wire for each ground, then you run wires out to the fuel tanks.

I ended up following the headset wires to the left and right, then tie-wrapped to the fuel vent line to the floor and then out the fuselage. Because the fuselage is double-walled, the snap bushing doesn't extend out of the fuselage. I'll put a dab of RTV in to cushion things.

Here's one side at the fuel tank:



And here's the other:



To keep vibration to a minimum, I ran the wire through a couple of inches of static tubing, which is a very hard plastic, and secured the line to the fuel line.

After checking everything, I powered it up. My family, which occasionally recalls when I was kid, my riding my bicycle five or so miles to watch traffic lights in Newburyport, Mass, will understand why I like this instrument so much.



I actually don't remember that much of the installation process, which took about three hours; I was thinking of my niece, Jennifer, and my twin brother, Bill. Jennifer's in the hospital and isn't doing well. I called Bill who was on his way to the hospital to let him know I'm thinking about them both and hoping for the best. If I could trade this damned plane in to make it so, I would in a second.

There a lot more items on that list on the dry-ink board. But I think for now I'll pull up a chair by the hangar door, and watch it rain for awhile.

A new instrument

I can't say I was particularly thrilled about cutting a new hole for an instrument in a panel I'd already painted -- there's really no way to avoid some scuffing in an operation like that -- but on the other hand, I've always really liked the Electronics International fuel level gauge, which has a descending series of LED lights to indicate fuel level in each tank. I've always liked pretty colored lights.

And, as it turned out, the Grand Rapids EIS (engine monitoring system) is better for the fuel flow indicator than the fuel level, so I wanted two data references in the panel to track this sort-of important thing. Plus, the EIS seemed kind of lame in the wiring, requiring a resistor to be connected between the wiring and the fuel level sender in the tank.

So today I punched through a new hole, and installed the EI fuel level sender. That's it just above the red knob (the mixture regulates the fuel and air mixture). Glad I left a little expansion space in my panel design.

I should be able to get it wired up pretty quickly. It's very simple, from what I can tell. Even I can't screw it up.

Next to it is the TruTrak autopilot. I have a wing leveler system but haven't been able to wiring it up fully yet because of some questions I have about how it's tied in to the GPS.

I sent a note to Stein at SteinAir but haven't had a chance to get together with him yet, but maybe you can help in the meantime. Here's the questions:


On the the transponder, there were two wires remaining with no apparent home:
SERIAL OUT 1
SERIAL IN 2

My setup is the Trutrak single-axis and the Dynon D100. The only GPS I have is a Garmin 296 in an Air Gizmo, although I'll probably upgrade to a 496 before I'm flying. Do these two wires have significance with my equipment and if so, where and with whom do they mate?

I'm also looking at the TRUTRAK harness kit with these 6 loose colored wires:

RED WIRE -- Power (I know what to do with that)
BLACK WIRE - Ground (I know what to do with that)
BLUE WIRE - Serial input from GPS (I bought the GPS Garmin cable, I assume this attaches to "Blue: Port one out" or "Violet: Port 2 Out". Is this correct? If so, does it matter which?
YELLOW - Dimmer (I know what do do with that. I think)
GREEN - To Altrak Pin 9. Since I don't have Altrak, I assume I just insulate it and wait for the lottery to do its thing.
WHITE/BLACK - To control wheel switch (from pin 2). I have on idea what this refers to. What control wheel switch?

Meanwhile, I have about three or four instruments with wires to a dimmer. Anyone want to guide me on how I would wire several instruments to one dimmer switch?

The first cut

There was no real reason to wait to start cutting the panel, plus the temperature pushed 60 out at the hangar today so the door went up for the first time.

I bought a Greenly punch (sp?) to cut the two holes for the backup airspeed indicator and altitude. I'm going with the 3 1/4" because, well, my eyes are old.

I had thought about getting the panel designed and then sending it out to be cut but between the cost of reducing the plan to CAD and then the cost of the jet cutter, plus shipping, I figured I'd be pushing $400. Airplane builders have been doing this by hand for generations and I'm really more interested in following them than the grand champs at Oshkosh.

Of course, the punch for the two round holes cost $140 so I'm not sure how much sense doing it myself makes. I only have one other circular hole that it can be used for (the autopilot), and then I suppose I can sell it.

Here's the original design:



I'm extremely mindful of what's behind the panel and as you can probably tell, I've already moved the Dynon down a bit. It's a tight squeeze between the backup instruments (I have a hunch I'll use the airspeed indicator as my primary) and the subpanel rib, which I moved a bit. There's not much clearance, but so far enough.

I'll have to check again to see whether the Grand Rapids EIS can fit under the Dynon still.

I also have to settle on what I want to use for a master and start switch. The "key" switch is a little pricey and it would take about 10 seconds to hotwire the engine to start (there'll be a lock on the canopy), so I may just go with a standard old throw switch and a momentary push-button for the starter.

I didn't leave myself a heck of a lot of room over the left for that. But we'll see. So far, so good.

Update Sunday 3/22 - Filing is fun:



Yeah, I know what you're thinking. Our little Bobby is growing up.

I've also played around some more with the design:



There's really less room in the panel than the Whiskey Victor panel builder suggests. I doubt there's room over on the left for the master switch (key) so I may create a row of switches where everybody else does. I moved the audio stack away from the far right rib and put the PS Engineering intercom back over there on the right, out of the way.

I'm not all that thrilled with all the space under the GPS. But I think it'll fly.

Update Sunday 3/22 6:28 p.m. The Air Gizmo instructions make reference to the radio tray so now I'm rethinking maybe putting it over there on top of the radio stack. That way when I win the lottery, I can buy a Garmin 900 and replace it.

I also measured off the location of the Grand Rapids engine monitor, centered beneath the Dynon D100, but it, filed the hole, and fit it.

Hangar flying the instrument panel design

I'm going flying today, but I'm not going to leave the ground. I've been working on the layout of the instruments in the panel, and now I have to go put it in the plane, sit in the seats and fly some "fake" flights to get the "human action" part of it down. Are all the instruments in a logical spot for the most efficient usefulness for the way I fly? We'll see

I did make some changes from the last revision I made using ePanel Builder on WhiskeyVictor.com. For one thing, that program doesn't consider the aluminum angle that is installed on the backside of the panel, all along the side and top.
I also realized the Grand Rapids Technology EIS 4000 engine monitor was in a dumb spot for me -- above the radio stack. I use the RPM indicator a lot when I fly, so I movedit over so it would be in the critical flight instruments grouping, just under the Dynon 100.

I also moved the PS Engineering 1000 over, closer to where it is on the Piper Warriors I fly. There's no reas difference, I suppose, than if I'd left it way over there on the right side. But it's something I'm used to.

I'm not sure I'm particularly thrilled with where I have the TruTrak autopilot control panel, but I'll lave it there for now.

I was mindful of some things I read in the article I wrote a few years ago -- Principles and Myths of Instrument Panel Design. Stein Bruch, Doug Weiler, Tom Berge, Tom Irlbeck had some good advice. One that was worth remembering is Tom's observation that for people who don't have much in their instrument panels -- and I certainly don't have much -- they tend to space things out, which prevents adding spiffy new things one might find at Oshkosh.

As you can see, I've left a lot of room to add things.

Update:


I took the panel out to the plane and did some mock flights and made some changes. The TruTrak autopilot is now just below the Garmin portable GPS. I've set up three groups, basically. Flight instruments, navigation, and radios. I moved the intercome to above the radio stack (I can expand the radio stack later and use the hole. I moved the ELT switch next to the transponder.

Here's my reasoning. I can now run an emergency situation and am the width of a hand from everything I need, ELT, switch transponder, shed load, communicate the emergency in this configuration.

I'm not particularly thrilled with where the TruTrak is, but it's grouped with the GPS -- navigation.

I've also got everything is withing a 'half-reach,' so that no matter how tightly I'm strapped in, I can reach everything with a minimum of effort.

Suggestions?