Grove Aircraft Company

Manufacturer of Spring Aluminum Landing Gear for Express

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You usually think of aluminum as a soft metal totally inappropriate for landing gear legs. With proper design and processing the aluminum stock is turned into a springy aircraft gear leg.

First the legs are sawn out of a sheet of 1½ inch think aluminum.

Next the final shape is cut with one of these two machines. The one on the left is a standard end mill with a special router bit that puts a rounded edge on the leg in one operation. On the right is a CNC mill making a more complex shape.

One feature of the Grove aluminum spring gear legs is the gun drilled hole that runs the length of the leg for the brake fluid. It replaces an external brake line, which reduces drag and you don't have to worry about damaging it.

I couldn't figure out what the term gun drill meant. It means a drill designed to bore the hole in a gun barrel. This machine is close to a century old and still working for a living.

Here is the new gun drill that Robby Grove, the owner, built. That's the aluminum gear leg laying on the table in the foreground.

Robby Grove is explaining the mechanism of the gun drill to Roy Davis. The electric motor on the right drives a very long drill bit that extends through all those metal plates. The piece being drilled is off to the left. The metal plates support the drill bit along its length so it doesn't whip around.

As the drill goes deeper and deeper into the gear leg the metal plates stack up on one another.

After drilling the brake line hole the aluminum legs are sent to a heat treater for annealing, which makes the aluminum very soft. Here's a batch of legs coming back. You want the aluminum as soft as possible so you can bend it without cracking. 1½ inch thick gear legs are a lot of metal to bend. There is a finished set of gear legs on the workbench behind.

Here is the gadget that does the bending. It's good for 80,000 pounds of bending force. Robby has a brand new 100,000 pound press waiting to be installed to do even heavier leg bends.

The gear legs have to be hand finished to smooth the surfaces, not only to make them look pretty but also to remove any possible stress risers.

A batch of finished spring aluminum landing gear legs. The legs for Express aircraft are then go to Olympia Powered Coating, right across the parking lot at our Builder Assist facility.

Here is one of our gear legs installed in a wing. We work on it upside down for convenience.

Click on the Logo to link to Grove Aircraft Company Web site.