Homebuilt Airplanes - Four Kinds
FOUR KINDS! What do you mean there are only four kinds?
And who in the world would build his own airplane anyway?
In these days of government over-regulation, product liability lawsuits, OSHA, union wages for aircraft manufacturing workers and maintenance mechanics (A and P's), it is downright refreshing to find out that it is perfectly legal for you to build and fly your own airplane. You can even design it if you want to. The thing that has made this possible is an organization of very stubborn individuals centered in Oshkosh, Wisconsin (formerly in Rockford, Illinois) called the Experimental Aircraft Association, or EAA.
Basically it works like this: An aircraft company must have any component used in any airplane certified for airworthiness by the FAA, a bureau within the Department of Transportation. This means that the slightest change in any component of any plane is very expensive, therefore it is next to impossible to make any improvements in any design. In addition the threat of lawsuits by plane owners inflates the prices of new planes by tens of thousands of dollars. But if you, the pilot, want to build your own plane, you can call it "EXPERIMENTAL" with a little sign on each side in 3-inch letters, and you can use off-the-shelf hardware from KMart if you want to!
A plane owner a few years ago went through all the paperwork necessary to get his production plane approved to use automotive gasoline instead of the more expensive aviation fuel (as you can guess, there isn't much difference). It cost him thousands of dollars and a lot of paperwork, but he may come out OK. Now, if you have the same kind of plane as his and want to do the same, all you have to do is buy a license from him for about $300 and you can use automotive gasoline too! Or, if you build your own plane, you don't need to bother with the permit, you can use an engine from a VW beetle, or a Ford pickup truck, or an army surplus generator (which has a Lycoming engine just like a production Piper Cherokee, only a lot less expensive, because, although it is exactly the same engine, it isn't government certified as airworthy).
So lets get to the point: What are the four kinds of homebuilts?
Before you decide to build your own plane, do the following. Get a license. Visit the museum at Oshkosh. Attend a fly-in at either Oshkosh (end of July) or Lakeland, Florida (mid-April). Join your local EAA chapter. Subscribe to Sport Aviation magazine. Get to know your local A and P (aircraft and powerplant) mechanic.
- The first type airplanes are those built of steel tubing, welded together, and covered with fabric. This is still a common type of aircraft design, but the steel tubing is now chromium-molybdenum alloy, and the inside of the tubing is rinsed with oil, filled with dry air, and welded shut and pressure tested to prevent internal rust forever! And the fabric cover, once cotton and covered with dope for protection from sunlight, and replaced every few years, is now dacron and good for decades of hard use. Example: Warner Revolution
- The second type is aircraft plywood and spruce. Hence the nickname for the largest plane ever built, Howard Hughes' Spruce Goose (he hated that name). The Wickes Lumber Company is a supplier of aircraft-quality woods for homebuilders (and also violin and organ builders). Nowadays the glues used to assemble the plywood and the plane itself are superior to those of a few decades ago, and wooden airplanes are still popular with some builders. I remember a sign on the wall of a wooden boat factory: "If God had wanted fiberglass boats, he would have made fiberglass trees." Example: Corby Starlet
- The third type of airplane (my choice) is the easiest for the amateur to assemble, because no particular skill is required. This is built entirely of aluminum. Extruded aluminum frames. Formed aluminum spars. Clad aluminum skin. Alloy aluminum rivets. Mass-produced factory planes have, for years, been all aluminum. I have personally visited the Beech factory in Wichita, the Piper factory in Vero Beach, and the McDonnell (now McDonnell-Douglas) factory in St Louis. About the only disadvantage to aluminum is the fact that it is corroded by salt. Airports, therefore, cannot salt their runways. Example: Zenith
- The last type of construction is becoming popular, especially with homebuilders. The non-stop round-the-world flight of Voyager, with Rutan and Yeager at the controls demonstrated how sleek and strong a composite airplane can be. Essentially the plane is carved in lightweight plastic foam, and covered with a tough skin of fiberglass or carbon fiber, impregnated with an epoxy resin. This makes the external skin of the plane very smooth, and since all the strength is in the skin, it can be inspected for flaws very easily. Disadvantages? It is a slow process to build, and produces a lot of dust and smelly solvent fumes. In a factory setting these planes will be very expensive. Examples: Vari-EZ, and Mike Arnold's AR-5 that gets 213MPH on 65HP!
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Updated October 17, 2011