After giving serious thought to the flight-testing procedure for a newly built kit several times, and more recently a scratch built “original” (there isn’t much original anymore), several questions come to mind.

Firstly, in the case of a kit, did the designer know what he was doing? Did he have any formal training; is this his first design; and more importantly did he adequately test the design? Many ultralight manufacturers have had no formal training and although this is evident in some designs, it isn’t necessarily the most important criteria. To know what he is doing seems to be the important factor. This can be learned or self-taught by observation, reading, listening, etc.

I don’t have the time right now to research the history of designers, but I remember several killing themselves while testing their new designs or modifications. This brings up another point; a designer/manufacturer will build a design, test it, change it and only test the modifications, but not necessarily the whole craft as modified. This has been the downfall of several would-be designers, and the fall is a long way down!

What about the manufacturers that let the customers test their designs? It is a good thing that General Motors doesn’t build aircraft, as they seem to test everything new on their customers. A manufacturer may show you a photo of many sandbags on an inverted wing laying between two sawhorses, but what about the wing attach brackets, or the relation of the tail to the downwash of the wing, etc.? You could be the test pilot and that job would either last the life of the aircraft or the life of the pilot. It seems that many ultralight pilots do not realize the dangers of this risky profession. I suppose they do not even think of themselves as “test pilots” but merely as pilot-owners.

The E.A.A. together with the F.A.A. is now studying the problems with homebuilders and “first flight” accidents. This is the time when homebuilders have problems, some fatal, and some very damaging both to the craft and the ego.

This particular time, the first flight after building a kit or even assembling a kit, is the time to do the most stringent walkaround and double check. If possible, have someone, preferably your dealer or another owner of the same type, check it over for you. I have found that even if you have excellent plans and step-by­ step instructions, builders will still interpret something differently than intended and will not recognize a problem until it may be too late.

Ultralight owners who do modifications open up another problem area. Every time you change something it usually affects several other areas. An example might be the simple addition to an existing design of a new paint job. What effect could this have on anything else, you ask? A simple layer of paint could move your center of gravity past the aft limit. In this configuration your craft may seem to fly well, but what will happen at the stall? Will it tend to spin? Will you be able to recover from the spin? Most real aircraft, when loaded with a rearward C of G, or past the limit, will not recover from a flat spin which will result from the rearward weight. The magic words are “Be Careful”. If you must make these modifications, talk to the manufacturer, they may have been there already and have pertinent information for you or advise as to what may happen.

Let’s continue this same senario; the paint job. To compensate for a nose up tendency we add a trim tab on one side of the elevator. This causes torque on the elevator leading edge torque tube and eventually might break the tube or jam the elevator in flight, likely with a disastrous result. Reading from a real airplane repair manual, it says if you paint the elevator, it must be re-balanced. There aren’t any balanced control surfaces on ultra lights, but this gives you an idea of what a little paint can do.

The most important step in building or modifying an aircraft is the weight and balance. If you don’t understand this procedure, ask someone to help. You must know the forward and rearward limits and stay within. Some designs, particularly two seat tandem craft, can be out of limit with too tittle weight in the front seat, with a solo pilot.

I will be doing a weight and balance on my aircraft in the next few days. If anyone would like to help and learn, please call me (226-0180).

It’s annual inspection time, have you done yours? How often should an annual inspection be done?