What are 'Experimental', 'Amateur-Built', and 'Homebuilt' Aircraft?
Since the Wright Brothers flew in 1903... well before that, in fact... people have been building their own aircraft. The reasons are varied, but typically people want to build for their own education, the enjoyment of building, and of course for their personal use and recreation once it's finished. An aircraft that is built by a hobbyist is registered in the FAA's "Experimental Amateur-Built" certification category (E-AB), and is most often referred to simply as an "experimental" or a "homebuilt". Homebuilts provide a degree of freedom to their builder in terms of certain maintenance and operational requirements which can become much easier and less expensive than those for factory-built aircraft with standard certifications. However, the flip side is that homebuilts have certain restrictions that factory-built planes with standard airworthiness certifications don't have... such as the fact that they (generally) can't be used for commercial purposes. So despite the performance advantages, you can't build a Kitfox or Glasair to use for an air tour or aerial photography business. But for the recreational or personal flying that many folks take part in, homebuilts are a viable option... and in some cases, they're almost the only option.
"Homebuilt" and "Experimental" - Isn't that kind of dangerous?
People unfamiliar with amateur-built aircraft are sometimes put off by the term "homebuilt" or "experimental", as these words can (somewhat understandably) conjure up an image of something less than a "real" aircraft, or something that's, well, "experimental" and unproven. But think of these terms in their purest sense... they merely mean that the aircraft isn't mass-produced in a factory, and the builder is free to experiment with the design. That doesn't mean he or she necessarily is building something completely unknown though... aircraft builders are strongly encouraged to stick to the plans, unless they have the know-how to engineer any changes.
In addition, whether a design is built exactly to proven plans or is a completely new design, all amateur-built aircraft must be registered with the FAA and pass a stringent airworthiness inspection conducted either by the FAA or an FAA Designated Airworthiness Representative (DAR) acting on their behalf. The plane MUST pass this inspection before it can be issued an airworthiness certificate and legally fly. While this is not a guarantee that the aircraft will fly well, or even at all, it does ensure that reasonable care was used in the construction, that acceptable methods and construction practices have been used, and that there are no glaring defects in the construction materials or methods used. Often, minor problems are found by the DAR (most commonly, these are non-mechanical issues... incorrect paperwork, missing cockpit labels, etc.) which are easily corrected. It is rare to find a problem at this stage that's so serious that it cannot be remedied fairly easily, but the experienced inspector tries hard to find anything that may cause a problem. Their goal is to ensure that the pilot will have the safest possible experience with their new aircraft. In reality, few factory aircraft could ever hope to match the quality and care of construction that's put into many homebuilt projects!
Once the inspector signs off on the airplane and the airworthiness certificate is received, the plane can begin its flight test period. The aircraft must be tested in the vicinity of the airport for a minimum of 25 flight hours (40 hours if it isn't using an FAA-certified engine installation) before the flight restrictions are removed... for example, passengers cannot be carried during the test period, and the plane must remain within a certain number of miles of it's home airport. During this time, the owner will find and correct minor issues and document the aircraft's handling qualities and performance, not to mention get experience with how to fly this particular aircraft. Upon successful completion of the test period, the testing restrictions are removed and the plane may then carry passengers, fly cross-country, and operate essentially as any other aircraft is allowed, with a few exceptions (for instance, amateur-built aircraft may generally not be operated for hire).
What does "Amateur Built" Really Mean?
In the eyes of the FAA, the term "Amateur Built" means that at least 51% of the aircraft was constructed by the builder for educational purposes (as opposed to being built for commercial purposes). Many aircraft are available as kits, and for the most part, a kit component must be virtually completely finished for it to not qualify under this rule. What the FAA wants to avoid is people trying to take factory-built aircraft, or their major parts, and making some small and relatively insignificant changes in order to gain the benefits of the E-AB category without actually having "built" the plane. You are free to use certified components, but don't imagine that you will be able to piece together a Cessna 172 from several wrecked airframes and get it certified as a "homebuilt"! Then again, there have been numerous examples of people making exact duplicates of airplanes (even including a P-51 Mustang) from original blueprints, using a few factory-built parts or engines and building up the rest in their workshop. These were considered homebuilts, because the constructor actually did build more than half the aircraft themselves despite the odd factory part used here and there.
What Kind of Aircraft Can Be Amateur Built?
The "Experimental Amateur-Built" category can include every type of aircraft. This includes balloons, ultralight-like aircraft, light airplanes, multi-engine planes, gliders, helicopters, gyrocopters, seaplanes, powered parachutes, and even high-performance jets. A homebuilt may be a one-off design that's scratch-built to test a designer's new idea, it may be built from a set of purchased plans, or it might be put together from a kit. Today, highly prefabricated kits are commonly purchased, where the builder becomes more of an assembler than a fabricator. Some people buy a used homebuilt constructed by someone else, and the new Sport Pilot category of aircraft has opened up new avenues to purchase light aircraft that are ready-to-fly or nearly so. In many cases, the quality, performance, and safety features of "homebuilt" aircraft far exceeds typical FAA-certified, factory-built aircraft... and usually at a much lower cost! Imagination rules, and many of the biggest advancements in aviation have been pioneered by homebuilt aircraft designers and builders. Burt Rutan, legendary engineer and designer of the Voyager, SpaceShipOne, Beech Starship, Long-Eze, White Knight, and countless other revolutionary aircraft that literally changed history, is just one example of this fact.
Time vs. Money vs. Performance vs. ?
However, just because many amateur-built aircraft cost less than a similar factory-built plane and/or have higher performance doesn't mean that they are right for everybody. There are many variables, of course, but many amateur-built aircraft projects will consume thousands of work hours and tens of thousands of dollars over several years before the aircraft is ready to fly. Generally, it is a poor idea to try to build a plane in order to have something to fly... you should build because you enjoy the process of building, and getting to fly it after you're done is the icing on the cake. Otherwise, you will end up frustrated when you hit a roadblock (and with any project of this magnitude, there WILL be some roadblocks!) If you really just want a lower-cost aircraft, or perhaps want performance that can only be found in a certain homebuilt design, you may well be best off buying a well-built and well-maintained used example that's already flying.
Of course, there are also designs which can be finished in weeks, and many ways to reduce the costs and time to complete a project. Often, it's the old "fast, good, or cheap... pick any two" situation. If you just want a simple aircraft for fun-flying "around the patch" and you aren't hung up on having the fastest airplane around, then you'll have many more choices available to you and a wide range of costs, performance, and configurations. If you want the most advanced airplane possible (featuring two engines, the latest advanced avionics, full pressurization, seating for eight, amphibious landing capability, and which goes 1,000 miles on two cups of muddy water) then of course you're looking at a lot of money and time and likely a lot of training too (that being a relative term, of course).
What DO You REALLY Want To Do With Your Aircraft?
A lot of guys are out there flying ultralights and similar aircraft that cost less than a typical 10-year-old used car, and sip a couple gallons of gas an hour. There are pilots who have built their own full-scale replicas of World War II fighter planes that have a million dollars invested in their projects. The most popular aircraft in the world (not just among homebuilts, but among ALL airplanes) are the Van's RV line, which typically cost about $60,000 to finish and will far outperform factory aircraft costing several times more. I've got a friend whose ingenuity and scrounging ability let him finish a Corvair-powered KR-2S for $7,300, everything included, which is well-built, safe, and yet will outrun any of the uber-expensive composite cruising machines. There are hundreds of folks building and flying the simple, inexpensive, all-wood Pietenpol Air Camper designed in 1928... and they're still built just about the same way that they did way back then. There are composite designs that literally unfold from flat sheets of material into elegant-looking composite airplanes capable of extreme performance. There are gyrocopters bolted together out of aluminum tubing and even homebuilt hot-air balloons where the major hurdle is learning to sew the nylon envelope together.
The best part is that every one of the folks described above is having fun and following their own personal dreams. You can, too! The biggest factor is your desire to see it through. If this idea intrigues you, perhaps the world of experimental aviation is for you!
As always, the best source of info on homebuilts is the Experimental Aircraft Association. Come to an EAA 1288 meeting, and in the meantime check out the EAA website. Maybe soon we'll be seeing you proudly telling folks about the new plane that YOU built yourself!