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As the maneuver continues, the pilot reduces the rudder pressure and uses coordinated flight controls to slightly bank the glider to fly along the top side of the box. The glider proceeds to the opposite corner using aileron and rudder pressure, as appropriate. The pilot maintains this position momentarily with rudder pressure, then begins a vertical descent by applying forward pressure to the control stick. Rudder pressure is used to maintain glider position at an equal distance from the wake. 

The pilot holds the wings level with the ailerons to parallel the towplane. When the glider has attained low corner position, the pilot momentarily maintains this position. The pilot releases the rudder pressure and, using coordinated flight controls, slightly banks the glider to fly along the bottom side of the box until reaching the original center low tow position. 

From center low tow position, the pilot maneuvers the glider through the wake to the center high tow position, completing the maneuver. 

Common errors when boxing the wake include: 

• Performing an excessively large rectangle around the wake. Figure 7-12  has exaggerated positions and is not to scale. 

• Improper control coordination and procedure. 

• Abrupt or rapid changes of position. 

• Allowing or developing unnecessary slack during position changes. 

## Ground Launch Takeoff Procedures 

When ground launching, it is essential to use a center of gravity (CG) towhook that has an automatic back release feature. This protects the glider if the pilot is unable to release the towline during the launch. The failure of the tow release could cause the glider to be pulled to the ground as it flies over the launching vehicle or winch. Since the back release 

feature of the towhook is so important, it should be tested prior to every flight. [Figure 7-13] 

## CG Hooks 

Some training and high-performance gliders have only a CG towhook. CG towhooks are necessary for ground launch operations so the glider is not pulled into the ground. Attachment at the center of gravity allows the glider pilot to have full control of the glider without undue influence from the ground pull. Attachment of a ground launch towline to the nose hook would tend to pull the glider into the ground and would overload the horizontal stabilizer and elevator. Conversely, depending on design, the CG hook may not have sufficient movement to fully release an aerotow line under pressure. If the hook only swings about 90° down, the towline may stay hung on the gliders hook until the pressure is released and slack allows the towline to simply fall off. It may be located either ahead of the landing gear, in the landing gear well, or the glider may utilize a bracket that attaches outside on the fuselage near the cockpit. 

If the CG hook is in the landing gear well, retracting the gear on tow interferes with the towline. Even if the glider has a nose hook, retracting the gear on tow is not recommended until the aircraft is safely airborne and an immediate or emergency return is not necessary. Leaving the gear down allows the glider pilot more time to assess the best landing options. 

A CG hook, as compared to a nose hook, makes a crosswind takeoff more difficult since the glider can weathervane into the wind more easily. In addition, a CG hook makes the glider more susceptible to kiting on takeoff, especially if the CG is near the aft limit. This can present a serious danger to the towplane during the aerotow. 

## Signals Prelaunch Signals (Winch/Automobile) 

Prelaunch visual signals for a ground launch operation allow the glider pilot, the wing runner, the safety officer, and the 

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