About Experimental LTA












Looking Back at the Launch Field Saturday Evening
XLTA Amherst 2005
Photo by Blair Beard

This website serves as a repository of information for people who build and fly their own lighter-than-air (a.k.a. LTA) aircraft. To use the official parlance of the FAA, these aircraft are called "amateur-built lighter-than-air experimental aircraft." This is often shortened to "experimental LTA" In aviation, the designator "X" often gets substituted for the word "experimental" -- as in "X-15." As a result, these aircraft are sometimes called "XLTA". Thus the name of this website.

"Standard" vs. "Experimental"

The word "experimental" in this context needs a bit of explanation. As far as the FAA is concerned, there are (more or less) two types of aircraft: 1) "standard type" aircraft and 2) "experimental" aircraft. Having an aircraft classified as "standard type" requires a multi-year and very expensive engineering review.

"Standard type" aircraft are what most folks see everyday. Everything from your local hot air balloon selling sightseeing rides to a Boeing 747 is a "standard type." In addition to an extensive FAA engineering review, "standard type" aircraft are assembled from closely scrutinized parts in a carefully controlled factory setting and undergo continuous and rigorous inspections. Construction of an "experimental" aircraft, while done quite seriously and painstakingly, has none of these exhaustive (and expensive) safety requirements.

Almost all of the experimental aircraft in the US are airplanes. Very few of them are anything like an "X-15." In fact, there are some very well-proven and highly-reliable airplane designs that are routinely built by do-it-yourselfers. Some particularly popular designs have been built hundreds and even thousands of times.

By any reasonable definition of the word, these tried-and-true aircraft are now very "standard" designs. Yet, because they haven't gone through the FAA's long and expensive formal design review process, they are (and always will be) classified as "experimental." It would probably be more accurate to call them "custom-made aircraft" because there is nothing particularly cutting-edge or tricky about their design. But they are very different from factory-built "standard type" aircraft in that they are custom-made by ordinary folks. Nonetheless, given the wonders of government bureaucracy, we're pretty much stuck with the term "experimental."

Like the folks who build tried-and-true airplane designs, most people who build custom-made balloons use very (from the engineering standpoint) conventional designs. The technology for hot air balloon design and construction is very well understood and hasn't changed much for many years. In particular, the technology for sewing the fabric that makes up the hot air "envelope" has remained essentially unchanged for many decades. So the creative impulses of balloon do-it-yourselfers are usually focused on the selection of the envelope colors and pattern, some variation in the shape of the envelope, and the workmanship that they bring to the task.

Ultralight vs. Experimental

Actually, I sorta fibbed when I said there were only 2 types of aircraft: "standard type" and "experimental." There is a third important classification: "ultralight" aircraft. Actually, there is a 4th called "light-sport". But I'll talk about that elsewhere.

"Ultralights" are really different beasts as far as the FAA is concerned. In fact, FAA doesn't actually deal directly with "ultralights" -- at all. That's right. If an aircraft is light enough there is absolutly no FAA involvement. No required pilot training, no airworthiness certification, no fees, nothing! The other neat thing about ultralights is that you don't necessary have to build it yourself. You can (perfectly legally) buy a factory-made ultralight and fly it without any of the usual "red tape" that involves the FAA.

Even though they don't "have to", some folks build their own ultralights. They do this for the same reasons that people build their own experimental aircraft. But, as with their factory-built cousins, do-it-yourself ultralights don't require FAA paperwork for either the pilot or the aircraft.

Now, all that's kinda cool. I mean, nobody likes paperwork. But keep in mind that ultralights are really really small. As a result, for all practical purposes, you can't take any passengers with you on an ultralight aircraft. This is particularly true for ultralight balloons.

In contrast, there is no such thing as a factory-made experimental aircraft. By definition, factory-made aircraft (or an aircraft made by anybody except an "amateur" as the FAA defines the term) has to be "standard type" (That's the kind that requires the really expensive and time-consuming engineering review process.) There are a couple of exceptions to this rule. But, more or less, experimentals require that you build it yourself and have a (often quite brief) conversation with the FAA.

A Rose by Any Other Name . . .

I use the term "experimental LTA" to include all LTA aircraft except "standard type" LTA aircraft. In this sense, the term includes both those aircraft that are officially "experimental" in the FAA's view as well as ultralight LTA aircraft. Perhaps it might be more clear to call them "unconventional LTA" or even "non-standard LTA." But then the next thing you know people would start quibbling about what's unconventional and what's not, etc. So I'll just go on using the term in the inclusive sense. Actually, I kinda like the term "custom-made" aircraft. But that doesn't cover factory built ultralights (Sigh.)

The Mystery of the Missing 2%

Building and flying custom-made aircraft (or whatever you want to call them) does not mean that you have to be a macho "Right Stuff" test pilot or some sort of daredevil. In fact, there are lots ordinary folks -- something like 23,000 of them -- flying various experimentals today. There's even is a big organization, called The Experimental Aircraft Association (www.eaa.org) whose main focus is helping people build custom aircraft.

As it happens, in total there are 625,000 or so pilots in the US. So that means about 3% of them are flying custom made airplanes. (23,000 divided by 625,000 is about 3%.)

Compared to airplanes, ballooning is a very small niche in the world of aviation. According to the US national organization for balloonists (The Balloon Federation of America -- www.bfa.net,) there are about 7,000 or so folks who fly balloons in this country. The number of people who fly custom-made balloons in the US is very small indeed -- certainly less than 100. That means that only about 1% of balloon pilots are flying custom made aircraft.

Frankly, it seems kind of weird to me that there are 3 times as many, percentage-wise, custom airplane builders as there are custom balloon builders (3% vs 1%.) The financial advantages, joy of creation, and other benefits of flying custom aircraft apply to balloons as much as they do to airplanes (in some cases more so.) Yet, the difference persists.

Perhaps this website will encourage some of "the missing 2%" to give custom-made ballooning a try.

All information on this site is subject to the following disclaimer.

Unless otherwise noted,
Copyright 2005-2012 Daniel Nachbar
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