2.4.2 Gaining Altitude
All Gliders fall, all of the time.
The secret to climbing is to fly in air that is rising
faster than the glider is falling. Generally, there are two types of rising air: thermals, and ridge lift. Rising
air is almost always accompanied by turbulence- what goes up must also come down.
Learn how to fly in lift from an experienced instructor. Begin learning to fly in lift conditions corresponding to your skill level. In thermals, this
generally means avoiding mid-day, and sites known for strong conditions and turbulence. In ridge lift, this means avoiding challenging sites and high winds.
2.4.3 Flying in Thermals
The ATIS has a low sink rate and is an agile glider. It is the perfect wing for thermal flight. The prevalent technique is to turn in circles when encountering thermals. In light thermals,
a gentle turn is appropriate to minimise the glider’s sink rate. Slowing the glider (brakes about 25% down, or at about the same level as your shoulders) and braking a little more in the
direction of turn (inside hand) while accompanied by a slight lean in the same direction will induce a turn that minimises glider sink. In stronger thermals, using more inside brake and raising the
outside brake will help centre the glider in the thermal and maintain more stability for dealing with turbulence.
In thermal conditions, rapidly falling air can be found near the boundary of the rising air, or anywhere. These conditions can result in some deflations of the wing and requires “active flying“ (section 2.4.5) skills to
maintain control.
Exercise extreme caution.
2.4.4 Ridge Lift
Ridge lift is the term given to lift generated by wind deflecting upward from features such as slopes, cliffs, mountains or ridges. The lift can be very smooth, depending on the wind speed and the size of the feature. It can also
extend to surprisingly high altitudes. Turbulence is generally associated with ridge lift either “down wind“ (also called “ee“ or “lee-side“) from the lift feature, or at the “edges“, where valleys, canyons or other gaps in the lift
generating feature occurs. Because of the wind speeds, (30 km/h is common for skilled pilots) trouble in these areas of turbulence can be sudden and violent. Dangers include being blown back into the lee-side rotor (rotary
turbulence caused by obstacles), and crashing into the ground, since ridge flying frequently occurs close to the ground.
2.4.5 Turbulence and Active Flying Skills
Flying with a little brake pressure on the controls helps maintain internal pressure in the wing and prevent collapses (caused by the air intakes in the leading edge closing). A pilot should learn to keep the wing
steady and over-head through minor adjustments of the brakes and weight shifting. This is referred to as „active flying“, and is the mark of a skilled pilot. When the wing moves forward, add brake.
When it moves back, let up on the brake. If it begins to turn without control input, correct with opposite braking and weight shifting. If the brakes „go light“, it may indicate an
impending collapse on that side of the wing. Increase braking on the light side and compensate with weight shift on the opposite side to maintain straight flight.
If you are not already exploring “active flying“, then you are not yet prepared to fly the ATIS in any conditions in which turbulence of any sort
may be encountered.
