Panel Design

The following issues are on the table to design the panel:

1. What I want to go on the panel

For the following instrument I will have to find space on the panel (assuming an analogue panel):

Flying Instruments

• Dynon D100 EFIS
• Backup Airspeed Indicator 
• Backup Altimeter (not legally required)
• Backup Artificial Horizon (not legally required)
• Compass

Avionics

• NAV/COM Garmin GNS430W
• Transponder Garmin GNX 330
• Stereo Intercom PS Engineering PS3000
• GPS Garmin GPSMAP695 
• 406 MHz ELT

Engine Instruments / Fuel Management

• Dynon D120 EMS

Electrics

• Hobbs Meter (not yet decided)
• Trim Position Indicators (elevator and aileron)
• Flap Position Indicator
• Annunciation Lights (Fuel Pressure, ...)
• Magneto Switch
• Switches (Master, Fuel Pump, Strobe, Landing-Lights, Taxi-Lights, Navigation-Lights, Instruments, Instruments-Light, Avionics, Autopilot)
• Fuses (COM, Transponder, GPS, Flaps, Trim, Autopilot, Aux)

The list got significantly shorter after we decided to install a glass panel... 

2. Panel Layout

I initially started on the assumption that I will install an analogue panel. The layout of the analogue panel of the SportCruiser, as proposed by Czech Aircraft Works, looks as follows (click on it to open as PDF):

It follows the standard T-layout, which I consider very important from an ergonomical point of view. I understand that this is not always possible due to space constraints, but sometimes I see panels where you really wonder who did the layout. 

Starting from this, but considering the changes in instruments and avionics, the panel would more have looked as follows:

The result was quite a number of individual units, and some items like the autopilot, fuel flow and CDI were still missing. That made me think a bit. 

My friend and co-builder Rolf then expressed his preference for at least a GPS with a large screen. Together with the missing items list I started looking into the glass version. Dynon had just released some basic information about the upcoming HS34 expansion module, which eliminated one of the main disadvantages of the Dynon, the missing possibility to enter certain data with rotating knobs (e.g. heading bug, air pressure).

The resulting first attempt, based on the Dynon D100/D120 combo and the AvMAP IV GPS then looked as follows:

In an attempt to optimize the layout, as well as to make it potentially IFR capable, I started looking at panels of commercial airplanes (see building log, September 2007). From that resulted the following improved version:

Here I moved the screens up, to arrange the ASI, Horizon, and altimeter in a row below the pilot's screen. In keeping the three screens at the same height I also moved the radio and transponder to below the GPS. That makes sense too, as at least the radio requires regular data entry.

As Dynon finally published new manuals for the D-100/D-120, which include the HS34 features, I realized how much functionality one can add if an SL-30 NAV/COM from Garmin is used. The panel would then have looked as follows:

The major disadvantage of this version was however that radio would not have been 8.33 kHz capable. This is currently no requirement except for IFR above FL195, but it might get a requirement for IFR in general and maybe even for VFR. So I started looking at alternatives. 

Becker announced an 8.33 kHz version of their radio in September 2008, so that was suddenly an alternative again. I produced a plywood version of the panel with cardboard instruments to speed up the search for possible layouts, resulting in the following versions:

When I thought I had finally found the best layout Garmin announced their new GPSMAP 695/696 series, which created an alternative to the AvMAP. I immediately made a cardboard front of the 695, but had to realise that it is not only a bit bigger than the AvMAP, but it also has to be oriented vertically. This did not leave room for the radio and the transponder. After some playing around with my cardboard instruments I came to the conclusion that the radio and transponder have to go into the centre console. The Becker radio and transponder would have fitted nicely into the centre console, but I was already hooked to the Garmin units which required widening the centre console. I did some test sitting and concluded that this would not disturb, so I went for that solutoin. The result looked then as follows:

After sitting for a while in the cockpit to see whether all buttons are conveniently located and all displays easy to read I realised that the EFIS was not straight in front of the pilot. That annoyed me, and some investigation confirmed that most planes, especially all newer ones, do have the basic instruments straight in front of the pilot. Ralf Kuerzi also confirmed that this is an FAA requirement for certificated planes, they typically only allow an offset of 1.5 Inches or 40 mm. I know that for experimentals it is not required that you follow such rules, but from my point of view it makes sense non the less. I therefore rearranged the left side of the panel to correct this, which resulted in moving the backup instruments to the right side of the EFIS. The panel now looks as follows:

 I guess this is what we will finally build.

3. Panel Parts List

The following table contains all items that will be placed on the panel, together with their maximum size (including mounting trays, including space for cables etc.): 

4. Panel Schematic

I will add the schematic of the panel, once it is available. 

© 2006-2007 Bernhard Stamm       last update: 01.02.2009