Powered Parachute Flying Handbook

Chapter 12 — Night, Abnormal, and Emergency Procedures

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 steering input to the opposite side. Hence, if the wing is hanging down on the left side of the cart, push on the right steering bar. The additional drag created on the right side will begin to pull the wing up to a more centered position (from being down on the left).

To compensate for the inertia of the wing’s movement as it is traveling upward, reduce the initial steering bar pressure, just before (not when) the wing is centered overhead. Then slowly add slight opposite steering bar pressure to compensate for possible over-correction (inertia) of the wing from center.

Remember: you do NOT need to manually move the wing center. The design of the wing and its attachment points create the tendency for the wing to be centered and overhead. You need only to steer the wing into the wind, allow the time needed to self correct, and provide the proper groundspeed to achieve proper wing position prior to takeoff.

The Cart Turns Over (Roll-Over)

During a PPC taxi, you have two entities to steer: the wing and the cart. Until united in an airborne pendulum, the independent wing can follow one path, while the “grounded” cart may insist on another. This can result in a pull-over. [Figure 12-6] Normally this situation occurs when pilots are not headed into the wind during takeoff, or try a crosswind taxi beyond the PPC limitations or their current skill level.

The strongest inclination of a taxiing ram-air wing is to weathervane. The wing wants to point into the wind. However, if the pilot is steering the cart in a different direction and has failed to notice the difference and has not corrected the wing over the center of the cart, then the wing can pull the cart over. The cart will be pulled over when the wing has been given the required airspeed to create the necessary lift to overcome the weight of the cart.

Since a taxiing cart has all its wheels on the ground, friction exists between the ground and the wheels. The friction causes the cart to travel in a particular direction. If the wing is in the air and pulling the cart in a different direction, opposing forces may be working against each other. You must prevent the wing from gaining enough force (horizontal lift) to pull the cart over on its side. Hence, caution must be used during taxi turns. Therefore, if the wing is not centered, and all the wing’s cells are not open, or the suspension or steering lines are not clear of debris and free of frame obstructions, DO NOT increase the throttle to provide the wing enough airspeed to generate lift. Either shut down or slow down while pointing the cart into the wind and then correctly build the wing.

On a takeoff or landing, when you get hit with an unexpected side gust of wind, or try to take off before the wing is centered, the cart may be placed into a condition where it could be pulled over on its side by the horizontal lift of the wing. During a pull-over, you will react to one of two possible situations:

1. Your cart is lifting on one side, but you still have time to recover.
2. Your cart is up on one wheel; past the point of recovery and beginning to tip over.

In the first situation, to enhance the recovery, immediately remove the lifting force from the wing by reducing the groundspeed (i.e., reduce engine RPM via the throttle).

In the second and most uncomfortable situation of not being able to prevent the pull-over:

1. Immediately place the magneto switches OFF, to turn OFF the engine and stop the propeller.

2. Do not try to prevent the pull-over with your body (i.e., sticking out your arms and legs). Pull your arms and legs up into a tuck position to protect your limbs. When the aircraft comes to a stop, immediately unstrap and get out of the cart.

3. In the event the situation does not conflict with the provisions of Title 49, Code of Federal Regulations, Volume 5, Chapter VIII, Part 830 (49 CFR 830), move the unit back into an upright position (to prevent gas and oil from spilling out).

Keep in mind the above paragraph does NOT imply a wing pull-over should ever be a normal or periodical occurrence. These accidents can cause death or serious injuries and damage to your aircraft. With the proper training and understanding, a wing pull-over is easily prevented during the takeoff roll if you:

1. Keep the cart headed into the wind.
2. Stay calm, relaxed and don’t rush your takeoff roll.
3. Realize it is the airspeed that is giving the wing lift, so slow down if you feel side lift and one rear wheel rising in a tipping fashion.
4. Let the cart settle back on all wheels as you maintain your heading into the wind.
5. Let the wing settle overhead, and allow all the cells to fully inflate.
6. Re-check the lines to make sure they are free and unrestricted.
7. Verify you do not have a “pig-tail” in the rear of the wing fabric or a friction knot in the lines.
8. Get your wing repositioned for takeoff, or abort the takeoff and get situated.

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