Landing Gear

The category of Landing Gear includes such tasks the gear wheel wells, brakes, brake lines, the (optional) parking brake, hydraulic system actuators, hydraulic system hoses and/or tubing, hydraulic pump, gear controller, and wiring and final adjustments.

I had several decisions to make in regard to the landing gear. The first, and main, decision was which size to go with. They offer a gear with smaller wheels, both for the mains and nose. They also offer a larger size.

Since this was one my first decisions that needed to be made upon arrival at the Build Center, I didn’t get a photo of the smaller tires to show you.

The smaller size is adequate for normal, hard surface runways. Plus, since the mains take up less space in the strakes, there is room for 2-3 gallons more fuel in each tank.

In my case, I chose the larger tires. I like the smoother ride, the somewhat more effective braking, and the ability to (possibly) land on grass. The only downside was the loss of some fuel. Operationally, that small loss of fuel has not caused any issues. As I said, the smaller tires are “adequate”, hardly a glowing endorsement. The larger tires are well suited to the V-Twin.

To retract the gear, a cutout needs to be made in the bottom of the strake. Also, space must be made for the retracted gear, including the gear leg. The pocket for the wheel and brake assembly fits flush within the strake.

Yep, I built it.

When the airplane was upside down, I sealed the gear pockets with Jeffco fuel tank sealant, and I made the gear doors. Basically, you take doors that are made for the XLRG, and hack them up, then reassemble to fit the twin.

While there are some other products that could have been used to seal the gear wells (and weigh a little less), this gave a really nice finish that is impervious to petroleum products. It looks really nice. I like it.

Here are the finished gear doors, ready for mounting. I also “bodyworked” the gear legs.

Installing the hydraulic pump, pressure switches, and pressure transducers.

Mounting the gear controller box. This box was supplied by a local subcontractor. In my opinion, it’s too big and awkward for the Velocity. It needs a repackaging of the design. In the meantime, Aero Safety Systems has developed an alternative controller that doesn’t need a big box. It’s not yet on their web site. You will have to ask. I believe it only works with the Garmin G3X system, but that may be old information. I would recommend it. It’s a better choice all round.

I made flexible hoses for the actuators and dump valve, and hard lines for the nose compartment.

This is the inside of the blue box. You can see all of the wasted space.

This is the airspeed safety switch. It prevents an early gear retraction. Unfortunately, it was set at too high of a speed. This is adjustment that I made. Now, you can retract the gear as soon as you have a positive climb, it comes right up. If it doesn’t, you can continue to tweak the adjustment.

For the nose gear, I dreamed up a custom bracket that is a combo tie down and tow bar attachment. Scott Swing made it for me. It works great with my electric tow bar and my ratcheting tie downs. I also added the Scott shimmy dampener, plus I had the entire thing painted with a nice, hard Imron.

One more mod I made was the “Don Johnston” seal for the nose gear. This greatly reduces the air entering the airplane through this gap. He posted how to do this on VOBA. VOBA is a membership group with annual dues. It is a great source of Velocity information. He also posted up an entire topic on his builder’s log about sealing the nose comparment complete with drawings on how to construct the above nose gear seal.

Since then, David Weaks has designed and sells a silicone rubber boot that addresses the same issue. It looks to be even more airtight. Installation does require removing the nose gear. Contact David at dweaks@yahoo.com

Continuing with the Landing Gear topic, I was not happy with the brakes as they tend to chatter and vibrate, plus they don’t have a lot of stopping power. At max weights, if you stand on them hard, you may experience fade due to heat build up. I intend to address this braking topic more in the future, but, for now, I installed thicker brake discs for better heat dissipation (1/2″ versus 3/8″). Scott made me some steel spacers for the calipers. (Yes, he is an outstanding guy, and an awesome building resource.) While I was going thicker, I used the Black Steel versions from ACS as they are reported to eliminate the chatter. I purchased mine at McFarland. The part number is APS164-02504.

It took a lot of research and seeking of advice to come up with this solution. It was Robbie Grove of Grove Brakes that advised me to upgrade to thicker discs for better heat dissipation. I appreciate his learned advice.

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