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limits (if applicable), and complete a final ignition
system check.
Once again, the pilot has this opportunity to establish
a go or no-go decision point. Check the intended runway
and traffic pattern for existing traffic, and if radio
equipped and a nontowered airport, announce field,
type of aircraft, runway heading, and flight intentions;
if a tower-controlled airport, contact ground or tower
control to request a departure clearance. By adding
thrust smoothly to about half to three-quarter throttle,
the powered parachute will begin the takeoff roll.
Wing Inflation and Kiting
During the takeoff roll of an airplane, the goal is to
build sufficient airflow over the wing to generate the
lift required to lift the aircraft off the ground. Powered
parachutes have two goals during the takeoff roll: to
pressurize and raise the wing overhead making sure
proper inflation exists for takeoff, and to create the
airflow over the wing to generate the necessary lift.
[Figure 7-3]
Figure 7-3. Pressurizing, or kiting, the wing.
Make a final check to confirm that the cart is pointed
in the right direction and nothing has moved into the
way. Look over your shoulder to observe the canopy
inflation. Advance the throttle smoothly and firmly
to about one-half to two-thirds takeoff power. Too
abrupt an application of power may cause the cart to
yank the wing too roughly forward. This can damage
the riser system and shorten wing life. This is more
of a problem with higher horsepower engines than in
lower powered aircraft. As the cart starts to roll forward,
make sure both feet are on the steering bars to
begin steering the parachute immediately.
As the wing starts to rise off the ground and climb, it is
acting like a parachute with lots of drag; the cart does
not move forward much. As soon as the wing passes
through the 50° angle to the ground, the drag dramatically
decreases as the parachute becomes a wing and
7-4
the cart will begin to pick up forward speed very rapidly.
You must reduce the engine thrust enough at this
point to prevent the powered parachute from becoming
airborne prematurely. If the initial thrust reduction
is too great, the wing will begin to lose pressurization
and settle back to the ground. If the thrust reduction
is not adequate, the powered parachute will continue
to accelerate and become airborne. On occasion the
wing can become locked-out, or stuck in the prop
wash; easing back on the throttle will allow the wing
to settle out of the prop wash. Once again, easing
the throttle smoothly forward will assist the wing in
climbing through the prop wash and climb overhead
above the fuselage.
As the wing is coming up in back of the cart, one side
of the wing may inflate and rise faster than the other
side. That higher side should be given a little bit of
steering control to allow the other side of the wing
to catch up. If you don’t make the correction early,
the wing will want to fly over to the slower-inflating
side. This may create wing oscillations, especially if
combined with too slow a takeoff speed. While it is
important to not over-control, remember that wing
controls during kiting are sluggish and more control
inputs are needed than during flight.
Now is the most critical point during takeoff and possibly
during the entire flight. While the parachute is
inflating and rising overhead, most of the powered
parachute’s weight is still being carried by the wheels
and the suspension system. The goal is to get the wing
overhead and then transition the load from the wheels
to the wing.
During the inflation and takeoff roll, you need to divide
your attention between the direction the cart is going
and the wing. When the wing is overhead, perform
the “rolling preflight.” You need to quickly inspect the
wing to make sure it is fully inflated and there are no
line-overs, end cell closures, pressure knots, or huge
oscillations before adding full power for takeoff. This
all has to be done with quick glances.
Line-overs are very easy to detect because the wing
will be obviously deformed and look like it is pinched
by the line that is over the top of the wing. If you see
a line-over, shut down and set up again.
End cells of the wing not inflating are something additional
to watch for. Most powered parachute wings
have large cross-venting in the cells to allow the
entire wing to pressurize evenly. Generally, the wing
will pressurize in the middle first. As the pressure
evens out across the wing sometimes the end cells of
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Powered Parachute Flying Handbook动力伞飞行手册(59)
