| The Challenger article (August 2003) really
got to me. If you are going to promote ultralight aircraft, try promoting
one of the better ones. I am 64 years old: I have been working on aircraft
for over 47 years. I started building model aircraft at the age of 6, and
I have had many formal course on aircraft and how they work. I will not
build a Challenger because it has no differential ailerons. The ailerons
are too narrow. The airfoil was designed by Barn-door Inc. The horizontal
stabilizer and elevator are too small. The fin and rudder are too small.
The tail boom is too short.
I am 5 feet 8 inches and weigh 200 lbs. When I sit in the back
seat, we have to take the seat cushion out so the pilot can use full-up
elevator. Some use full-up flap on the flaperons as up trim to keep the
nose up. this means that the front of the airfoil is producing positive
lift and the back is producing negative lift. This is anti-productive.
One owner took the left-hand door off his aircraft and went flying. On
approach he decide to do a sideslip to the left. The aircraft spun around
like an anemometer and landed flat in the approach part of the runway.
Another owner who had just finished his aircraft had an experienced
Challenger pilot test fly his new aircraft. A few minor adjustments were
made, and he decide to fly it himself. He pulled the aircraft into the air
a little too soon, and a light crosswind picked up the right wing. He put
in full right aileron. The first response of the aircraft was a large
negative yaw to the left.
This made a tricky situation worse, so he throttle back and put in a
bunch of rudder. Both the ailerons and the rudder we not effective enough
at this speed with no power, and the aircraft continue left crashed and
was destroyed.
You see, on a flaperon equipped aircraft, when you lower the flaps you
create reverse differential ailerons, and it makes negative yaw effects
worse.
There is a long-wing version of the Challenger they call the soaring
version. Soaring aircraft are called gliders, and they have a glide ratio
of 15-1 or better. I challenge you to climb to 5300 feet above the
airport, travel 12 miles out at that altitude, shut the engine off, and
try to glide back to the airport.
In the "for sale" sections of newspapers, there are always several
Challengers for sale, always some with very low time. The builder is
willing to lose $5,000 to $8,000 in order to get rid of them. Why is that,
do you think?
Cliff Stacey.
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