曝光台 注意防骗
网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者
lock, or an accessory—then while safely maintaining
your ground direction into the wind and holding your
RPM down to kiting speed—reach out and push the
line off of the restricting object. If this is not possible,
then shut the PPC down and abort the takeoff.
To abort a takeoff (i.e., to shutdown) maintain your
ground steering clear of obstacles as you: (1) power
down the throttle, (2) push the magneto switches into
the OFF position, and (3) pull the wing down.
Entangled or Embedded Lines
If the lines become entangled or embedded with debris,
then shut the PPC down and clean up the lines.
If you don’t, and you load the wing by beginning the
lift-off, the stress on the lines as they pull through
the debris (twigs, sticks, and so forth) can break the
lines.
Lines Caught Under a Wheel
If the lines go under a wheel, IMMEDIATELY abort
the takeoff. Shut down: power, magnetos and wing
down.
A Wing Wall
The term “wall” is simply defined as the canopy literally
forming a wall-like appearance behind the PPC.
[Figure 12-3] The trailing edge of the canopy is still
on the ground, while the leading edge of the canopy
forms the top of the wall. The “wall” is the first canopy
problem that might occur during the initial kiting
of the wing.
Even though some pilots will try to “pop” the canopy
out of the “wall,” the only safe solution is to immediately
abort the takeoff, and re-layout the canopy. By
shutting down and restarting the takeoff preflight, pilots
will save the expense of many line and propeller
repairs. Lines will inevitably become damaged when
a pilot tries to “pop” the canopy out of the wall via
sharp throttle movements. When you fight the wall,
you create an ideal situation for lines to get sucked
into the propeller.
A Wing Lock-Out
A wing “lock-out” occurs when the initial forward
momentum is insufficient to move the canopy through
the prop-wash and up and above the PPC cart. [Figure
12-4] During this phenomenon, the inflated canopy
will hang at about a 45° angle behind the cart. This
is a “parachutal-wing stall” while the pilot is still on
the ground. Usually, regardless of how much groundspeed
is increased, the wing will stay in a parachutalwing
stall behind the cart as long as the tension on the
suspension lines remains the same; the wing will stay
“locked-out” in that 45° position.
Figure 12-3. A wing wall.
Figure 12-4. A wing lock-out.
There are two techniques that can be used to correct
this “parachutal-wing stall” position of a rectangular
wing:
1. Lower the groundspeed until the canopy begins
to fall down and back behind the cart. Then
before the wing touches the ground, smoothly
and firmly increase the groundspeed to move
(“sling-shot”) the canopy up and above the cart.
2. Maintain the groundspeed and pull the canopy
back via a flare (i.e., pushing both foot steering
bars). Hold the flare until the drag caused on the
tail of the wing pulls the wing back down—about
a 60° angle—
and then smoothly release the flare.
The release of the flare will again “sling-shot”
the canopy up and above the cart.
12-4
Note: Ask the advice of an instructor before using
these techniques on an elliptical-shaped wing. The
characteristics between the two types of PPC wings
are significant in correcting the “Locked-Out” scenario.
Wing Not Centered Overhead
No takeoff should ever be attempted until the wing
is centered above the cart and forward to the riser attachment
points. [Figure 12-5]
Hence, if the wing is not centered when it comes
ahead to the riser attachment of the cart:
1. Keep steering into the wind, and
2. Keep your groundspeed below airborne (liftoff)
speed.
The most noteworthy aspect of the takeoff preflight
roll is to verify that the wing is positioned correctly.
Due to the design, the wing will normally want to
be up and centered above the cart. It also wants to
weathervane into the wind. If you don’t rush the takeoff
roll, and give the wing the time and speed it needs
to adjust and settle overhead, the takeoff will be fine.
The wing wants to be centered over the cart and pointing
into the wind. You must steer into the wind during
the entire takeoff roll.
You can adjust the wing’s position during your takeoff
preflight roll once the wing is up and past the 45°
position. When the wing is down on one side, apply
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：
Powered Parachute Flying Handbook动力伞飞行手册(90)
