Engine controls on or below panel?

[Pbruce]

I have throttles on the left of the cockpit, but the mix, prop, and carb heat will go on the left lower corner of the panel, or under it. I see more examples of the former case than the latter. I’m wondering what drove the decision to add the sub-panel below the instrument panel for engine controls? I’m about to lock in my instrument panel and I wonder what I should consider: room on the panel, ergonomics (which is better) ease of construction, or…? Since I don’t know what I don’t know, I thought I would ask those who have gone before. Thanks.

[spinningwrench]

In my case I didn’t want anything taking away leg room so everything went on the sidewall and panel.

[Pbruce]

In my case I didn’t want anything taking away leg room so everything went on the sidewall and panel.

Thanks Bruce. Did you find any particular challenge in doing so which would have been eliminated by hanging them on a small sub-panel below?

I do have access through removable side panels on the boot.

[spinningwrench]

If you mount any vernier type controls on the main panel you need to be very careful where you place them as they have a surprisingly long body that could interfere with the fuselage brace tubes. I built a mock-up of my panel which I could bolt in place and had to shift the location of my mixture and prop pitch controls to make them work. My throttle and carb heat are on the sidewall quadrant.

[podo]

In this version of my panel I have my EFB on a Ram mount taking up the space for engine controls so I'm going with below the panel for mine... until I change my mind again.

[rodsmith]

I mounted my engine controls centered below the panel and cabin heat and headset jacks in the corners. It definitely limits leg room for someone with long legs, not an issue for myself. I can see that in a crash my right leg will most likely contact the center sub panel and cause additional injury. For that reason I almost decided to remove it, probably would have if it hadn't involved cutting off the welded steel angle that the controls mount to. The corner pieces are only about 2" wide and don't present the same issue. I realize Bruce is talking about his Patrol, I would think carefully about leg room, both for getting in and out, and what would happen in a crash.

[Pbruce]

Excellent points, all. Thanks. As usual there are more considerations than I expected, so I’m glad I asked.

[Bcone1381]

Background:
What drove my decision design and create the Engine Control Sub-panel is because I want more space on my panel. (Mark keeps improving Kits so yours may be larger.) So, The sub-panel was created. My left leg has abundant freedom. There are no normal operations where I wished I had that space free to operate the aircraft. Ergonomics are equal I think. Ease of construction played little in my thought.

A design theory:
My panel is shown below in the photo. It's designed with no Circuit Breakers, Intercom, Headset Jacks, or USB ports on the factory panel, but the ELT panel on the far right is a waste. I will have no naviagation display attached to windows via suction cups, viced onto my control stick or velcroed on top of the boot cowl under the windshield.

And Industry Best Practice places two Engine Controls on the left side instead of one. This can be done when quadrant is fitted below AND under the window sill with the levers penetrating the interior fabric. I tried but gave up. Others have succeeded. Creative use Adle clamps may avoid welding as you create your setup. I know Mark has improved this to be a bolt on option now. 2017 era kit builders have to design and fabricate it. New Kits will save a month's time in this area.

The Patrol fits big guys and the sub-panel consumes some space. DO NOT underestimate Seat Cushion thickness. Mine are 4 inches. Three Inches can be shaved off my seat bottom and back would give enormous space. I wont...I love my seats...thanks to Pauls Johnston, Patrol Builder/Upholsterer.

Another area to exercise your creativity are two tubes rising up like the letter "A" with the apex meeting where the bottom windshield/ cross tube at the bottom of the panel/side window sill. My interior fabric ends at one side of the "A". Can you attach the Prop and Throttle there with Adel Cushion Clamps? I see now its possible I might use them instead of my Sub Panel with its dangerous edge. During a crash I could have issues with the lower edge of aluminum below the Prop Knob cutting into my left thigh. I'll investigate.

Always be mindful of the flap handle. I need two inches clearance to keep from skinning my knuckles.

In my photo below You can see what SpinningWrench cautions you about the space constraints of long vernier tube that extend out the back of those controls. These are MacFarlane controls.

Bottom Line:
Patrol Builders should sit in their airplane and understand their space constraints. Be creative, sit on phone books. use poster-board mockups, dream and plan and understand your space. I'm 5'10, 160lbs. Many Patrol builders have a different build than me. I have zero concerns with the sub panel space consumption.

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[Pbruce]

My panel looks to be about the size of yours. It’s exactly 8” high in the center. Unfortunately, that’s a smidgen too low to fit my Garmin 796 vertically, so I’m will probably lay it on its side on the right side of the panel in an Air Gizmo panel-mount.

I am inclined to use a GRT sport EFIS in the center. If I can sell the 796 for a decent price I’ll get the big GRT screen and if I can’t, I’ll get the little one. I mainly want it for the engine management capability and to eliminate all other instruments. I’ll need one radio and a transponder head. I like those ones you used. Very neat and compact! The 796 is a just great GPS. I just wish I had figured out the sizing before, and made the panel a half inch taller. Like you, I don’t like anything that is not flush panel mounted. I also have an SDS electronic ignition panel (slightly smaller than an iPhone) which would ideally be mounted on the panel, but could be also mounted out of view below in some kind of fold-away fashion.

I was able to get my throttle box embedded in the side panel with only the throttle lever sticking into the cockpit. If that sub-panel was made with a roll or a couple of folds at the bottom, maybe that would satisfy the crash-safety element, and make it inherently stiffer. Great point about the seat cushions. I hadn’t thought of that.