Most of what I would call the “mechanical stuff” is grouped here The panel has undergone a number of changes over the years: V.1 used sliding potentiometers for control over flaps, mixture and propeller pitch. V.2 added custom buit mechanisms for the landing gear, flaps lever and the airbrake lever. V.3 has completely redesigned flaps and airbrakes systems and brings some of the components more in line with what you would find in the B-737 cockpit.

Evident changes from V2: the gear annunciator lights are now similar to the real thing (no more F-16 stuff here). The lights panel is also inspired by the B-737 cockpit, albeit slightly rearranged because of space issues. In the B-737, the lights switches are located in the lower part of the overhead panel.

The flaps lever mechanism was completely redesigned. Now, the lever must be pulled before it can be moved up or down.

The airbrake system also underwent major changes. It now contains an analogue axis, allowing for much more precise control over the airbrakes’ extension during descent. Last but not least, the panel is now fully backlit, including the landing gear and airbrakes scales.

Some areas in the image on the left are clickable for access to more information on the components built into this panel.

Another change from previous versions: The panel is now built from two layers, making it look a bit more 3-dimensional. Previous versions were all flat. I decided to paint the base plate grey and print all labels in a much darker tone. Letters and lines are now much easier to read.

Backlit panels require more planning during the design stage. In places where the transparent upper panels have letters, appropiate openings must exist in the base panel. These openings are usually irregular, because I try to leave as much contact surface as possible between the two panels.

A detailed view of the backlight LEDs under the landing gear plate.

I had planned to use 5 spider LEDs but ran into space problems with the center left LED during the modification process. The only solution was to use a sub-micro LED (just a bit over 1 x 1mm in size!). During istallation I cursed the size of my fingers, but in the end I managed to fit the LED into that tiny space.

The Mechanics Panel – V.3, fully assembled and mounted on it’s plywood base.

I guess the parking brake switch can not really deny it’s automotive heritage. But it looks so cool when the transparent lever starts to glow red in the on-position. I admit I simply could not bring myself to changing it for something more airplane-like.

The flaps lever contains a tiny LED that lights up green while the flaps are in transition.

This angel shows the immense size of the flaps lever. But once the panel is installed in the cockpit, it leaves no no clue about all the stuff that extends “below the surface”.

The airbrake lever is rather long, and as a matter of fact could, in the full down position (airbrakes extended) collide with the trottle, if the throttle were advanced beyond 60% of its travel. But this is an unlikely case to happen, since these two positions should be mutually exclusive. The only exception I could think of is during a Touch & Go.

Anyways, my EPL script does not allow the airbrake lever to move down if the throttle is in the way. It also retracts the airbrakes automatically (i.e. lever moves up) as soon as the throttle is advanced beyond 30% after touchdown.

You might wonder what the protruding box with the three black bolts is good for:

It acts as a counterbalance for the handle of the airbrake lever. Because the bolts add some mass, it also makes the tactile sensation while moving the lever much more credible. At the base of the gearbox is a velcro-covered clamp that adds resistance to the lever movement. The amount of resistance is adjustable by tighening or loosing two small bolts on this clamp.

The two small plywood boxes left of the ToGa button and left of the airbrake lever contain Spider LEDs for backlighting. The rest of the backlighting is inside the gearbox, hidden from view.

In order to avoid electromagnetic interferences, the DC feeder cables to the electric motor and clutch are each wound several times through ferrite cylinders.