Getting Started in Homebuilding, Part 3 of 11

Budd Davisson, EAA/Experimenter, 1994

Picking a Design

Picking a design? Sure, that's no big deal! Just get out the design catalog, skim through the 487 designs listed, throw a dart, send a check and start building. Simple as that.

Yeah, right!

The process of evaluating the design, doesn't start with the design. It starts with the builder, the guy/gal who has to stick all those pieces together and then is going to count on them staying stunk when he/she flies it.

What that says is the design has to be looked at from two points of view: as a project to be built and as an airplane to be flown.

If however, those two points of view, building and flying, are held up to a mirror, it will be clearly seen that behind both stands the reflection of the individual who is both the builder and the pilot. The builder/pilot is what has to be evaluated first.

A design doesn't stand out there by itselt. For the years it is being built, it becomes part of the family. For the years it is being flown, it carries part of the family. So, the family and lifestyle the builder, and how that prospective design fits into it has to be looked at carefully. A life is composed of about a trillion pressures and unknowns and tossing something as big as a homebuilt project into it makes major ripples. A design is much more than a shapely bucket of bolts. It is a tangible force that, while building, sucks up time, money and patience, and when finished, sucks up still more time, money and patience. All of that has major effects on a family.

The design absolutely has to be a perfect fit with all aspects of a wannabee builder's life or it won't be finished.

Airplanes that are still-born and lay in the garage forever begging for someone to finish them wind up that way because one of the ingredients for a successful marriage between man/woman and machine was lacking or inadequate. More likely, the design was selected and the building started before enough thought was given to how that particular design was going to fit into the big picture of the builder's life.

The most common mismatches include:
· Underestimated Time and Interest Requirement. The builder didn't properly evaluate the amount of time it was going to take to build an airplane and lost interest . Any airplane needs a minimum of three years at 3 hours a night, three times a week.

· Finances Weren't Adequate. Some designs take more money than others. This is often driven by the size and cost of the engine and whether or not kits or finished components were used.

· Family Wasn't Taken Into Account. The time to build has to come from somewhere. If it comes out of a family situation that can't tolerate it, the project, or the marriage, is doomed.

· Builder Wasn't Willing to Learn Skills Needed. Airplanes need all sorts of different skills, all of which can be learned by anybody, but the builder has to be willing to expand his skills.

· Building Environment Didn't Match Design Requirements. Some airplanes take more space than others. For instance, a biplane needs a lot less space than a monoplane with a one piece wing. Also, if the workshop has the atmosphere of a dungeon, it doesn't encourage the builder to spend hour after hour there.

· Design Required Equipment The Builder Couldn't Afford. Aluminum airplanes need riveting equipment, rag and tube machines need welding. Different designs need different equipment. If it has to be borrowed or work farmed out, that complicates the project immensely.

So, when looking at a given design, it has to match the builder in at least the following ways:
· Financial
· Time to Build
· Skills Required
· Workshop capabilities
· Equipment

Mission Must Be Defined
A major problem with selecting a design out of the sea of designs out there, is determining exactly what the pilots wants to do with it. One minute he sees himself blasting off for a hamburger in Miami, or Cleveland, the next he is doing an exquisite three-dimensional ballet that would make Wagstaff jealous and the next he is shoe-horning his airplane into a strip so short helicopters avoid it.

Figuring out the actual mission of the airplane is probably the hardest part of picking a design. Here too, the first thing to be examined is the pilot/builder and his life. He might want to go to Miami or Cleveland on a regular basis, but does his family and/or job give him that kind of time? He might want to be pulling 9 positive and pushing 6 negative with great regularity, but will he want to bring others with him and how much hard akro will he actually do on a normal flight?

If he wants to work sport type airports with grass runways usually much shorter than the norm, is he going to be willing to give up high speed performance so he has the slow speed, short field capabilities?

It's all a trade-off and the wannabee builder absolutely has to recognize the differences between what he wants, what he needs, what is practical and what is possible. it ain't that easy!

Picking the Category
Airplane designs break themselves into five basic categories with a couple sub-species of each. Those design categories are:
· Serious cross country - 190 mph or better
· Cross country airplanes - 125 mph- 190 mph
· Eventually I'll Get There Cross Country Machines - 100-125 mph
· Forget It, I'll Stay Around the Airport Fun Machines- 100 mph and down
· Specialty Machines - Akro, shortfield, etc

Each of these categories could be sliced up a couple of different ways, including categorizing by materials or whether they are kit or plans built.

Serious Cross Country airplanes, especially those above 220 mph are usually composite kits, which is another way of saying they can't be built cheaply. That is also another way of saying they demand a certain level of pilot profeciency to keep up with them. These are also airplanes that are much happier on medium length, paved runways. If the pilot is good, the runway smooth and the approaches clear, 2,500 feet would be a minimum length, with 3,500 being a better situation.

The pure speed of the composite bullets is glamorous, but it really isn't all that important except on extremely long cross countries and in the bar afterwards, when bragging about cruise speeds becomes paramount. It is cheaper and easier to just lie. There are dozens and dozens of airplanes that fall into the cross country category, ranging from Thorps and Midget Mustangs to any of the RV series, All are fine on grass and don't demand quite so much out of the pilot. Many of these airplanes are aluminum, which means they can be plans built, if wanted, also the kits are usually less expensive because the materials and manufacturing tooling is less expensive.

Every airplane is capable of cross country flight. It all depends on the ability of the pilot to sit for long periods of time until enough real estate has been covered. It becomes a question of how much the human body can take. Cubs have been flown cross country and Florida to Alaska with great regularity. Never underestimate the ability of the human body to endure. So, picking 100 mph as the bottom of the cross country category is arbitrary. At that level, however, yet another bushel of designs and are available in all the building materials, composite, rag and tube, aluminum and wood. The beauty of this category is that many of the airplanes use engines which are small enough their cost isn't cause for heart failure. There are even a number of two-stroke designs that fall into this category.

The around-the-patch birds are of every possible variety and cost. Avids/Kit Fox types are in this category, as are Wag-Aero non-Cubs and non-Vagabonds. Old Baby Aces fit in here right along with Pietenpols and Heaths. These are fun airplanes. Producing smiles is their mission in life and they fullfil it beautifully.


A Guideline
At the beginning of this treatise, we used the number 487 as the number of available designs and that is a real number based on a complete compendium compiled by a noted magazine last year. It may not be exact, but it does give some idea why it is so easy to get confused. However, there are some iron clad rules that should be followed in evaluating any design. To many folks, some of these may appear too conservative, but, when it comes to devoting several years of your life, and then trusting the rest of your life to that design, there can be no such thing as a "too convervative" approach.

The Ten Commandments of Selecting a Homebuilt Design

1. Don't be a Pioneer - Use the Rule of Four In Three
The rule of four says you don't built an airplane unless at least four show up at Oshkosh within three years of the introduction of the design. If that's not the case, then something is missing in the formula that is described by the commandmants that follow. Classic cases include nearly 300 (Mary, check that number) VariEzes in that period and dozens of RV-3s. Good designs with good systems behind them catch on and literally take off.

2. Evaluate the Support System
A design that has no builder support system, even if it is an older successful one, may not be the proper choice for a first timer. The kit manufacture should have a system for handling builder questions by telephone and a newsletter has come to be expected. Newsletters are a great forum to share builder information so even those out of contact with other builders won't have to re-invent techniques and fixes. The newsletter also is a pipeline for manufacturer or design changes that may be safety related.

3. Check Plans for Completeness
So many airplanes have been built from little more than a dozen pages of Xeroxed drawings, it proves the plans don't have to show every part for an airplane to be completed. But that's not for first time builders. The less there is left to the imagination, the more chance the airplane will be finished.

4. Make Sure All the Kit Installations are Available
Any number of homebuilders have been stranded, when they got caught in the "..the next kit installation is in the mail..." syndrome. Kit manufacturers don't plan on screwing their builders, it just works out that way, when they run into financial or technical problems and can't deliver. Unless gambling is a natural part of your life, don't order a kit until it is all available.

5. Get a Ride
Once you've narrowed your design choices down to one or two, if necessary, pay a rediculous price for a ride in it. Any amount of money is a fair price, since that is the only way you can actually experience the design first hand. That is how you find out you are six inches too tall to fit, or the airplane causes your mouth to fill with cotton on final. One flight in the right airplane would have made many builders change their minds and saved them thousands of hours and dollars. Incidentally, don't ride with just anybodyl. Make certain the airplane has been flying for a while and the pilot has plenty of time in it, at least 50 hours in the past six months or so.

6. Talk to at least Five Builders
Don't talk to just one builder. That one may be either the best or the worse of the bunch. Try to hit enough that you can draw an average. That also allows you to get builders who are in different stages of construction and can give different views on how easy the airplane goes together, how responsive the manufactor or designer is to questions, whether the quality is what it should be and a dozen other things. Ask questions and most builders will give more information than you actually need.

7. Talk to at Least Five Pilots
Here too, don't talk to just one pilot, his background will color what he says about his airplane and his airplane may not be representative. Draw an average and take into account the different wieghts of the airplanes and the engines installed.

8. Check EAA Safety record
The EAA keeps reports available on all homebuilt safety related incidents and these are available to members just by calling headquarters and asking for Ben Owen. The number of accidents isn't as important as the types of accidents. Some airplanes have a lot of accidents simply because the pilots start showing off too low, too early. Others show a need for improved pilot technique in fairly normal operations. The reports can tell a lot about an airplane design.

9. Join An Association
Some designs have their own association that may even have their own newsletter. These are good for exchanging ideas and parts.

10. Find a Builder in Your Area
There is no substitute for being able to actually see the airplane in process. Besides that, the builder can become a valuable source of information because he has already done everything you are about to do and you can see it first hand. There are lots of places in an airplane, where simply seeing it makes what was a murky part in the plans crystal clear.

To summarize: First look at yourself, then look at the airplanes. The best design in the world is worthless if it doesn't fit the person.