On 28 Dec 2003 01:26:51 -0800, (-=:|SAJAN|:=-)
wrote:

Well as far as i know the concept of home homebuilt aircraft is very
vague because it would work only the aircraft controls are very easy
to understand or a person building it a pilot himself, else, either
the aircraft would crash or it wouldn't take-off.

Homebuilt aircraft are designed to be flown by trained pilots. Over the
past 100 years, standards have been developed for how aircraft controls
work, and, with very few exceptions, homebuilt aircraft controls work
exactly the same way.

If a person does not have a pilot's license, he or she should obtain the
proper training before flying their homebuilt aircraft...and, in my
opinion, should gain that training before starting to build the aircraft.

The second thing is
that if they are factory made then such aircrafts would be too costly
to be owned by a common man. Is there really any cheap and durable
homebuilt aircraft?

The high cost of a factory aircraft stems from two particulars: The labor
cost of assembly, and the high cost of dedicated aircraft engines.

The labor cost issue is the foundation of the homebuilt movement. Instead
of, essentially, paying a company to assemble an aircraft from raw
material, the homebuilder does all this labor himself.

In many cases, the materials and methods used to build the plane are
identical to those used to build production aircraft. Hence, the
durability should be the same, *providing* the builder of the aircraft
demonstrates the same level of expertise as the factory workers assembling
the production planes. This is not difficult to achieve, and many
homebuilt aircraft include extra design margin to allow for
less-than-perfect workmanship.

Another way to compensate for workmanship problems is to produce the
homebuilt aircraft design as a kit. For instance, instead of having the
builder buy raw aluminum and cut out the parts, some homebuilt kit
companies provide pre-cut and pre-drilled parts. Unfortunately, the cost
of performing these tasks is then passed to the homebuilder in the form of
a higher kit price.

Some homebuilt aircraft designs are intended to be built in an absolute
minimum amount of time with an absolute minimum cost. In these cases,
durability of the design may not be equivalent to that of a production
aircraft, due to simplified construction procedures and less-than-optimal
materials.

To paraphrase a common saying: "Build Fast, Build Durable, Build
Cheaply...pick any two."

As I mentioned earlier, the other major cost factor for production aircraft
is the cost of the engine. Production aircraft are required to use engines
that have passed extensive requirements and have obtained government
certification. Since relatively few of these engines are built every year,
their per-unit cost is quite high...they *start* in the $25,000 range.

Homebuilders have alternatives than can lower the cost of the aircraft.
While the cost of new certified engines is high, used examples can often be
found for a lot less money. In addition, homebuilders can take more-common
engines, such as those used in automobiles, and convert them for use in
their aircraft.

When the homebuilders use certified engines, the durability of the engine
is practically the same as that of production aircraft ("practically,"
since it does depend upon the builder's workmanship when installing the
engine). Many people have had good results with engines not designed for
aircraft, but there are usually "teething pains" involved in such
installations.

Homebuilts can be significantly cheaper than production aircraft.
Durability of the homebuilt can be the same, but this requires attention on
behalf of the builder and raises the costs slightly.

Keep in mind that *all* aircraft require periodic attention to maintain
their durability. All types of aircraft, if neglected, can develop the
corrosion and other problems that can affect durability and safety.

In my particular case, I've got a 22-year-old wooden homebuilt with a
certified engine, and it's doing nicely (bar a recent episode of dry rot in
the tail post). I've got one friend with a thirty-year-old aluminum
homebuilt who's doing fine. Another recently completed the restoration of
a fifty-year-old aluminum four-seat homebuilt, and the work he performed
was primarily elimination of corrosion. Not unexpected, when no interior
corrosion-protection was performed when the aircraft was built....

Ron Wanttaja