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See also
Sport Pilot as it relates to adding wheels for tandems.
2008-Jan-15 "A helpers" added at right.
"Eventually, we'll all be on
wheels."
That may be true but I've
seen some 70+ year old foot launchers making it look easy. One prolific
Instructor, Don Jordan continues to fly and teach foot launch at 71
years old (as of 2007).
Many pilots choose to roll
instead of run for its own sake. It's fun. There are distinct advantages, too. For
flying at high elevations or doing tandem instruction it's dramatically
easier than foot launching, allows pilots to carry more, is easier on
the legs and back (with proper suspension/protection) and is less
dependent on perfect winds.
Most powered paragliders can
be quickly mounted/dismounted to a wheeled cart, giving the pilot a
choice.
A powered paraglider trike
(or quad) is, by definition, a foot launchable unit with wheels added.
What separates wheeled
powered paragliders from powered parachutes is the wing. Paragliders are
efficient which is why we can use small enough motors to foot launch—but
they require more pilot expertise. Powered parachutes are easier to
learn but require gobs more power to plow their inefficient square
canopies skyward. Elliptical powered
parachutes wings close the gap with heavier PPG trikes. One trike,
developed by Chad Bastian, has foot steering hookups intended to be
connected in flight. That's how powered parachutes are almost always
flown—with your feet.
Recent Observations of
Wheels
 In
2007 I tripled my experience with trikes. The picture at left shows my
first foray into high powered PPG trikes, flying Jim Doyle's Hirth
powered behemoth down the runway while keeping the nosewheel aloft. It
was flown under a Sting 250 paraglider.
What I've discovered is that,
if you can competently handle the wing, transitioning to wheels is quite
easy. I've also learned a lot about the different dynamics of trikes vs
quads, line holders, attachment points, wheel choices, frame styles and
riser connection methods. After seeing some expert trike pilots through
many launches, I've discovered that you can recover surprisingly crooked
launches with appropriate finesse. I've also seen how quickly a new
pilot can flip his craft and break an arm. Proper training and student
attention to their instructor is just as critical for learning trikes as
it is with foot launching.
Something else that has
become clear is power. Unless you're planning to foot launch your unit,
thrust is good. Although it can twist pretty good, wheeled craft
typically torque less than foot launch because the axis of torque is
farther away from the axis of twist. Overall, more power is easier to
manage on a trike and more beneficial to launch.
Innovation continues apace
and it will show up periodically here when appropriate.
Trike Risks
As pointed out in the PPG
Bible, the biggest risk on wheels is tipping over during takeoff or
landing. Designs should protect the pilot in a rollover such that his
head would not impact the ground.
The vast majority of trike
injuries come from rollovers where the pilot puts out his hand and it,
or the arm, gets broken. That happens regardless of protection because
pilots don't keep their arms in. Obviously if your unit won't provide
proper protection of your head in a rollover there is little choice.
Most provide some protection by virtue of requiring a cage hoop that
sticks well above the pilots head.
If you have a design that has
good protection, rehearse what to do in a rollover: hands in, head down,
kill the motor. "tuck, roll and terminate (the motor)"
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A-Helpers
To make launching easier, A-Helpers (also called A
assists) are sometimes used.
A Helpers are lines that go from a frame part to the
A-risers so you don't need to hold the A's during launch. As the wing
comes overhead, geometry is such that the A-Helpers go slack—perfect
since they're not needed anymore.
1) Probably 90% of all tandem powered paraglider
training is done on wheeled units.
2) Big power keeps this powered parachute flying in order to overcome
both the heavy weight and inefficient but stable square canopy.
3) Quads increase ground stability but do not eliminate rollovers. |
