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18.04.2019

Landing Gear Lever

The landing gear lever can be the <g> key on your keyboard, a push button or a flip switch, depending on the degree of realism you are trying to achieve in your simulator setup. In the first version of my cockpit I used a big flip switch, the type usually found in cars or trucks. It did an ok job, but for V.2 of my cockpit I wanted something more sophisticated.

Even though I have been in many airliner cockpits over the years (either on the ground or in-flight), the crew never let me touch the gear lever – there are good reasons for this, so I did not argue.

Once however, I had the chance to fly a MIG-21, or to be precise, a MIG-21 full motion simulator. It was great fun, since I managed to land the beast (but that is another story, to be told on another page). I did try the landing gear lever in that MIG cockpit, and it had a peculiar but logical way of working: In order to avoid accidental use (maybe with the pilot’s knee during an SAM attack?) the lever can not simply be pushed up or down. No matter if it is in the up or down position, it first has to be pulled towards the pilot and only then can it be moved vertically. That’s where I got the idea from, and I decided to implement this gear system into my own cockpit.

Design

After a preliminary scetch, I fired up my trusty old Corel Draw program and started to … well, … draw.

The design is actually quite simple. The wave-shaped piece in the top section allows movement of the lever only if it is first pulled. The lower end of the lever assembly actuates the switch. The lever travels along its axle when pulled. This is the reason why the axis hole in the lever is oblong and not round. The spring is compressed when the lever is pulled. Once the lever is moved up or down and than released, the spring pulls it back into the fixed-position. The trickiest thing was to shape the lower end of the lever in a way that it always forces full travel of the switch below. Since the lever has longitudinal as well as rotational movement, this required some fiddling. Depending on the size and form of that switch, copies of my design can and will vary.

Material

I have no access to sophisticated milling and drilling equipment, so I decided to build the lever from sandwiched layers of 3mm acrylic glass. The electric switch actuated by the assembly is actually the same I had used as gear lever in the first version of my cockpit. It has a long plastic lever, so the landing gear lever will always flip the switch, even when it is fully pulled out.

The casters used to impede direct vertical movement of the lever are taken from an audio cassette (there days are numbered anyway…).

The lever itself is cut from a 2mm metal sheet to which the acrylic parts are glued and bolted.

Building

Building is easy. Just glue all the parts together. I found that quick setting 2-component glue works fine, as long as the acrylic glass is first sanded. Glue does not stick well to a polished, hard surface. For reinforcement I used 3mm bolts. Where needed, I glued the bolts in and cut off the heads, to obtain a flush surface.

It is a good idea not to use glue on the top layer of the assembly. Better fix it with bolts and nuts. That way it will be easy to service or change pieces inside.

Experiment with the spring. The design allows for 2 springs, but I found out that one is enough to push the lever back after pulling it (and to impede movement of the lever without pulling it first).

Stress testing

Once the unit was built, I spent a hole evening moving the lever up and down occasionally, thus simulating roughly 30 years of use in my cockpit . It survived and shows no cracks or other signs of fatigue. These signs appeared on the face of my wife though, who probably assumed I had finally gone mad…

Finishing touches

Once mounted in the mechanics panel, most of the gear lever is “below the surface”. Only the lever shows and thus needs painting. Depending on the strengh of the springs employed, the panel holding the assambly should to be rather sturdy. It would be a pitty to rip out the whole panel in those nerve-wrecking moments before touchdown, only because you pulled the landing gear lever too hard, wouldn’t it?

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