Light Stuff

Assembly is homebuilding, too.



There are major differences between airplanes and the rest of aviation. For one, there are a lot more airplanes pushing their way through the skies than any other category of aircraft combined. Also, building airplanes normally takes a lot more time than building aircraft in other categories. This is partly because of their wings, which typically include a multitude of parts (unless they are made of composites, in which case there is still a lot of time invested in the construction). Compared to rotors, parawings and weight-shift-control wings, airplane wings can be downright intricate.

The Breezer is delivered as a quickbuild kit. Plenty of the assemblies are already built up and ready to go.

These factors have combined in the past to make it difficult for the FAA to know how to deal with Experimental/Amateur-Built (E/AB) other-than-airplane (OTA) aircraft. After all, it can easily take many hundreds of hours to construct an Amateur-Built airplane, even with a quickbuild kit. Other powered categories of aircraft, including powered parachutes, weight-shift-control trikes, gyroplanes and even helicopters, often take a lot less time to build. If, as an FAA inspector or a Designated Airworthiness Representative (DAR), you are used to seeing nice, fat, builder logs, it can be disconcerting to meet a powered-parachute builder with less than 100 hours of build time in his or her aircraft.

For years, builders of simpler aircraft were sometimes penalized by FAA inspectors for those short build times. The admonition was, “You need to build 51% of the aircraft.” The inspectors didn’t always understand that 51% of a really small number is an even smaller number.

Somewhere along the line, it became common within the FAA to require that 51% of an aircraft contain parts that were “fabricated” by the amateur builder. That left some OTA aircraft builders out in the cold because critical parts such as pre-welded fuselages, rotors and parawings come factory-made, just like pre-welded fuselages, propellers and engines do for many airplane kits. That made those aircraft kits more like assembly kits, which was frowned upon, despite the FAA’s own regulations. These regulations state:

§21.191 Experimental certificates are issued for the following purposes:

(g) Operating Amateur-Built aircraft. Operating an aircraft the major portion of which has been fabricated and assembled by persons who undertook the construction project solely for their own education or recreation.

Game Changers

The E/AB kit world has now evolved to a state in which airplane kits have increasingly become the quickbuild variety. Certainly, some of that was market-driven. In a fast-paced world, most people have less free time to dedicate to aircraft building and want to get into the sky sooner rather than later. Some of it was also quality control on the part of the kit manufacturers. The more that is done at the factory, the less opportunity for error on the part of the amateur builder.

Chesapeake Sport Pilot displayed an entire MT03 gyroplane kit at Sun ‘n Fun 2010.

Add to that the commercial assistance providers. Those are the A&Ps and experienced builders who help owners build their kits and get paid for doing it. There is nothing wrong with that until the airplane ends up being less than 51% built by unpaid amateurs. (Is there any other kind?) In some cases it got out of hand, so much so that the only work some owners were contributing to their projects was the skilled application of their signatures to the bottom of their checks.

This resulted in a complete review of the Amateur-Built process and the creation of a new checklist for Amateur-Built airplanes, new and updated FAA orders, Advisory Circulars and an Amateur-Built Aircraft National Kit Evaluation Team (NKET).

Until recently that seems to have worked out well for airplane kit manufacturers, but not for others. The problem was that the new documentation really didn’t address OTA aircraft. Part of that was a matter of priorities. After all, there are a lot more airplane kit manufacturers and airplane builders than there are for other categories, so it made sense for the FAA to start there. But meanwhile, FAA inspectors and DARs were being told that they had to use an approved checklist to inspect all E/AB kits. The problem was that the only approved checklist (OK, the only checklist, period) was for airplanes.

This hurt those building OTA aircraft. The gyroplane community was hit the hardest, because nearly all gyroplanes constructed now are Experimental/Amateur-Built, as they don’t currently qualify for Special Light Sport Aircraft (SLSA) or Experimental Light Sport Aircraft (ELSA) airworthiness certificates. (That is another regulatory issue to be discussed another day.)

Most powered parachutes are built as SLSAs or ELSAs, including the Maverick flying car by i-tec in Florida. However, i-tec also began building a version of the Maverick that has more than two seats, which put it outside the limitations of an SLSA powered parachute. That meant a checklist was needed for that category of aircraft.

These two motivated groups began work with the FAA, which also wanted to provide valid lists for all categories of E/AB aircraft.

The Breakthrough

The problem that quickly came to light was that most OTA aircraft kits are assembly kits, and the parts that need to be assembled are the same parts that are provided by airplane kit manufacturers. For example, welded fuselages are commonly factory-built and supplied to the airplane kit customer with no build penalty. The same goes for gyroplanes and the Maverick. The big difference is that most of the aerodynamic surfaces on aircraft other than airplanes are bought off of the shelf, much like a propeller is, and that leaves little fabrication, but still a lot of assembly.

The FAA came to understand this about the different aircraft and designed checklists for them that reflected this new understanding. Now homebuilders for the most part get as much credit for assembling parts as the factory gets for fabricating them. Most structures need fabrication or assembly, so the tasks break down the center as far as the amount of work that goes into the final product.

As a builder of powered parachutes, I can vouch that the new program is realistic. I’ve gone through the new checklist, judging the kits I used to build for myself and customers as ultralights, and the numbers work out well. I’ve often

suspected that the kit assembler had more work in the project than the kit fabricator did, so it seems fair all the way around.

How It Works

Before builders begin constructing an aircraft, they should know that the aircraft they intend to build meets the 51% Amateur-Built standard. The easiest way to do this is to work with an approved kit. Approved kits can be legacy kits developed prior to the new policy, or they can be kits approved by the NKET. A visit to amateur_built/kits will lead you to the updated kit listing as well as checklists and other valuable information. However, just because a kit is on the list, it does not mean that it is available new or even that the company still exists. That isn’t a lack of due diligence on the part of the FAA, a lot of old kits are still floating around out there. If you find one for sale—even partially completed, but with a decent builder’s log—you could conceivably buy that kit and complete it yourself.

If a kit is not on the list (or even if it is), you should download the “Amateur-Built Aircraft Fabrication and Assembly Checklist (2009) Job Aid” for your chosen category of aircraft. The checklist will help you decide whether the kit truly leaves you 51% or more of the work to do. It also will help you decide whether parts of the project can be completed by a commercial assistance provider, should you decide to go that route.

All of the checklists have six item columns. They include Task #, Listed Tasks and columns to fill out describing whether the task was done by the Manufacturer, Commercial Assistance, Amateur Builder (Assembly) or Amateur Builder (Fabrication).

Not all tasks apply to all aircraft models, and if a particular task doesn’t apply, you aren’t penalized for it. That task just isn’t counted. For remaining tasks, the effort to complete them is divided among the manufacturer, the commercial assistance provider and you, the amateur builder. Your data is entered into either the Assembly column or the Fabrication column, but never both, because tasks are each designated as one or the other. In fact, the form handily blocks out areas where numbers shouldn’t be entered. For any given completed task, the numbers across the row should add up to one.

For example “Fabricate Exhaust System” may be shared by you and the exhaust manufacturer. Rotax provides tabs that need to be welded onto its two-stroke engine exhaust systems. You may give yourself .2 or .3 points of credit for the welding if you do it, because the manufacturer would properly be getting .7 or .8 points for doing the lion’s share of the exhaust-system fabrication. If you go to a welder to have that work done, the welder would get the credit for the .2 or .3 point as a commercial assistance provider, and the manufacturer will still get the balance.

But when it comes to the item “Assemble Exhaust System to Engine” you would likely get the whole 1 point, and the manufacturer and commercial assistance provider nothing, because you did the work.

To put a finer point on things, say you get some help from a buddy, who happens to weld the tabs onto the exhaust system for you. As long as he isn’t paid, he maintains his amateur status as far as your project goes. That means that you get to keep the .2 or .3 credit toward fabrication.

Ultimately, the total amount of credit you get for assembly would be divided by the number of tasks. This is added to a similar calculation done for fabrication. By the time you get to the end of the checklist and add the values in your fabrication and assembly columns, you have a number greater than 50%.

Luckily, the process is straightforward and realistically assesses the amount of work you need to do on the project to qualify for an airworthiness certificate.


Pictures and Builder’s Log

The new checklist does not eliminate the need for documenting your work with a builder’s log and photographs. In fact, one of the most important photos you can take is of your kit as it arrived from the factory. Spread out all of those glorious parts on the shop floor and take a picture of them for your “before” shot. Then, as you work on your project, continue to document what you do (as well as what others do for you) in your project log. Take photos along the way to go with the builder’s log text. The more you can provide to back up your checklist, the better.

Keep a working copy of the checklist with your builder’s log as you construct your aircraft. Start with your estimates of what you are doing versus any work you contract with a commercial assistance provider. If this changes along the way and you seek help for something you had planned to do yourself, you should understand how it will affect your numbers.

For example, the task “Assemble Wing Steering Lines to Canopy, and Steering Line System to Airframe Structure” is fairly straightforward for an experienced powered parachute builder. However, when you open the box with your parachute, you will learn that nearly all parachute wings come with the steering lines preassembled to the canopy. If you were counting on that being part of the build, you need to make an adjustment. And while attaching the steering line system to the airframe structure is not difficult, you may decide to leave it to a professional. This means that credit you may have counted on toward the build is lost. Leave yourself a cushion when it comes to tasks you plan to complete so that you don’t come up short at the end of your project.

Revolutionizing Kit Aircraft

These new FAA checklists are a big help for the OTA aircraft community. They demystify the construction of an Amateur-Built powered parachute, helicopter, gyroplane or weight-shift-control trike, and may even help open up the market to more affordable aircraft from both domestic and overseas aircraft manufacturers.

Roy Beisswenger is the technical editor for Powered Sport Flying magazine ( and host of the Powered Sport Flying Radio Show ( He is also a Light Sport repairman and gold seal flight instructor for Light Sport Aircraft as well as the United States delegate to CIMA, the committee of the Fédération Aéronautique Internationale (FAI) pertaining to microlight activity around the world.

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Roy Beisswenger
Roy Beisswenger is the technical editor for Powered Sport Flying magazine ( and host of the Powered Sport Flying Radio Show ( He is also a Light Sport repairman and gold seal flight instructor for Light Sport Aircraft as well as the United States delegate to CIMA, the committee of the Fédération Aéronautique Internationale (FAI) pertaining to microlight activity around the world.


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