The concept was to protect the pilot from the stinging
rain while not sacrificing any visibility. Access and egress into the
pilots seat should not require complex contortionary skills and most of
all... handling characteristics should not be altered.
After several attempts with "D" cell shapes and using
the "'Ole pickup truck- test bed wind tunnel" the best shape was mounted.
The first flight was truly an eye opener. Not only was
90% of the relative wind blocked... but the expected decrease in cruise
airspeed did not happen. Instead we increased our cruise speed by 7
what a pleasant surprise.
The next flight consisted of adverse flight handling
characteristics. We expected to experience some type of odd effect on the
control surfaces. NOPE!! the Bubble had NO ill effect on any
control surface. The stall, slip, yaw and spin characteristic of our test
plane was not affected in any way.
I've had the Bubble mounted on a Sport II and brought
it to 84 mph (full power, two people and nose very low) with no problems.
This was done for testing only!!!!! Published VNe
for the Sport II is 75 MPH and should be observed.
FLIGHT INSTRUCTION is
simplified with the bubble. Using ultra-thin pin stripe tape apply a
vertical line in the center of the bubble. Also, run several horizontal
lines intersecting the vertical lines. These lines are approx. 2" apart
and 12" long. Now you have a reference to the horizon with degree
increments. This makes flight instruction a piece of cake, just set the
horizon on the cross marks and cruise, climb, turn and descend without
wondering about angle of attack.
Construction is simple. 1/2" X .035 alum. tubing makes
up the frame. 1/16" clear lexan is the cover. The whole thing is attached
to the airframe using heavy duty tie-straps.
The Bubble kit has been pre-drilled. This is done by us
building the bubble on our jig then disassembled and packaged for UPS
shipping. Work by the customer consist of Popping about 100 rivets and
drilling two 1-1/2" dia. holes for the steering rods if used.
Added weight is approx. 15 Lbs. which is usually welcomed on most
Sports and Sprint