SonexBuilders.net

Light IFR Panel Design (Planning to fly in Southern California where there is typically an overnight/morning cloud layer)

Left to Right
Left sub-panel
Ignition Switch, Coil, Fuel Injector, and ECU circuit breakers
Panel/Interior lighting dimmer switch, Alternator warning light, Warning/Caution Light, G5 Standby Instrument
PFD
GDU460 PFT
Avionics Stack
GMC 507, GNX375, GMA 245
Avionics Power Switches and Circuit Breakers
Alt/Bus1, Avionics, Pitot Heat (Regulated Gap 26), Nav, Strobe, Landing/WigWag, Fuel Pump 1, Fuel Pump 2
MFD
GDU 470
Radio Stack
MGL Vega Radio Heads attached to V16/N16 Set to GNC 355 Protocol x2
Right Sub Panel
ELT, Bus 2 Power, Cockpit Lighting, Aux Power Switch(USB Charging ports)

Rear Stack
Not Pictured but plan to do something similar to another builder with Circuit Breakers for the Servos and powered Bose Audio plugs + non powered standard plugs.

The plan is to do a vertical extension in the center.

Or instead of going up, you can go down with the extra needed space. That is what I did. I'm 5'7" so I have the space to fit my legs under the panel with no issue. Then there is no reduction in viewing out the windscreen straight ahead.



Rick Caldwell
Xenos 0057

Sonex isn't really an IFR platform, but I appreciate the cloud layers you want to bust through quickly to get on top.

My thoughts (all $0.02 worth)
The G5 is a great backup with the HSI capability, having the 2 G3X screens and a G5 is more for heavy IMC flying. Unless you have a Lycoming stuffed in that thing, I wouldn't recommend heavy IMC.Therefore, I'd:

- Remove the 2nd G3X screen, drop the MGL radios (they are meh at best) and go with Garmin remote comms. They are awesome with the G3X and the removal of the G3X will cover the costs.
- Center the 10" to minimize view issues out the front edges of the panel (approach view point), even consider going lower than higher
- Rearrange switches and other items to keep the radio stack from extending up
- Move the remote ELT switch to behind pax head for easy pilot access

My original panel design was a single gdu 460 but I am a bit concerned about engine sensors if I lose the PFD, Down is a consideration but I am 6ft and have read a few complaints about extending down instead of up. and there is the structural consideration of the bottom lip although I saw a pretty nice solution using aluminum angle that solves that concern.

Cost wise the straight comms from garmin are cheaper but the nav/comms are half the price of the Garmin equivalent and they still interface with the g3x. If I go single panel I would def want a radio interface so I can still communicate in a single panel setup.

And I agree I would not want to fly hard IMC in one of these little planes due to the stability design but for a thin 500- 1000 foot stable marine layer I don't think its an inherently dangerous platform but every persons risk tolerance is different. I would def not shoot an approach to minimums or fly convective or event heavy IMC in this plane YMMV.

That being said I guess I have more to think about now.

Makes sense on the going up vs down if you’re taller. Re the second EMS onscreen, I’d say that if you lost the GDU and its battery backup, I’d go full rich and get down right away because something went really wrong.

Yeah I am thinking in terms of just loosing the screen not necessarily a full power failure but I am planning to go dual bus anyways with a secondary battery on bus 2. engine is fully electronic so it would just be a matter of get on the ground now, but that would always be the case with any kind of electrical fault given the fact the motor is electrically dependent. I was thinking more in terms of it would be nice to know its still going voltages etc to estimate how much running time I have left. but yeah the more I think about it the more I think a second screen is overkill I already have a 10in ipad so I don't have so much of a need for the moving map. it really was more about engine redundancy. then again aeromomentem has an all in one engine instrument I can piggy back with can so I could with the extra panel space just toss that onto the panel I think I will mess around with that a bit

Updated design for single screen


I guess I have some time to simmer on it this would be less work overall and reduce the amount of panel overhang I would have the G3x is still slightly off center but I anticipate I will do a lot of 2 person flying at least that's my intended mission so the fact its offset left I think is better than being centered. The offset is also small enough that center seating will still be fairly reasonable to execute. the switch guards were used to space the intended USB Charging ports there just is not anything in the database for the panel designer in the right dimensions and those switch guards are slightly larger than the dimentions of the intended charging ports. the grey cutouts are for the air vents originally I was planning to toss them on a top lip like another builder but if I am not going up as far then there it does not make sense to reduce visibility.

The guarded switch is a hard switch to disable the garmin envelope protection for flying light acro

Is there enough room behind the panel for the GNC 355? It extends almost 12" deep.

That's a good question and i am not sure yet, The GNX 375 is about .75 inches shorter than the GNC 355, worst case senario i bite the bullet and go with a GPS 175 which is half the length of both of those other options but honestly i would really like to not have to go with something other than the GNX375 dollar for dollar if you want to throw a navigator in its the best deal compared to having to install a seperate transponder. Might be another reason to go with the vertical extention on the panel.

LakeSpookie,

N43WX's question is valid. I just went outside to measure and indeed there is less space available than required for the GNC355. From the front panel to the fuel tank measures 11.125". Given you will need space for wiring and connectors I do not think this will be a viable option. I personally would go for the 10" screen and use a slim Nav/Com like the GNC255 that way with the thinner height, and mounted low on the panel it will miss the tank. Just my $0.02. Best of luck, and let me know if you need any additional help.

-Tim