Date: Aug 3rd to Aug 6th.
One ground school day. 3 flying days.
Price: $1195 + tax + tips (optional)
Place: Tiger mountain, Issaquah, Seattle.
Instructors: Matt, Austin, Brian
How thermal is generated
- Sun heats ground. Ground heats air.
- Hot air wants to rise; cool air wants to sink.
- Air mass has the tendency to stick to the ground. Area that heats air and trap air mass is called collector. Examples: crop field, dry grass field, forest, rocky terrain.
- Trapped hot air stick to the ground until it meets a point to release. This point is trigger. Examples: top of a sharp peak, boundary between a large dry field and a green field, a tree line. These triggers does not move. They are also called passive triggers.
- Active triggers are triggers that move, such as tractor, people, car, or a landing paraglider.
- When thermal keeps going up and meet the dew point. cloud forms.
When flying, actively find collectors, triggers, and cloud. They give us clue where the invisible thermal might be.
A good collector, the area that heats up air the most, are those that 1) has been in the sun for a long time; 2) has a perpendicular angle towards the sun; 3) the surface air has not been disturbed by the wind.
- So a good collector source is the south-east facing lee side slope for the morning.
Thermal features
- Thermal is a column of air mass. They drifts by wind much slower than paraglider.
- So, when thermalling, push to upwind a bit more to stay in the thermal. Turn tighter in downwind side.
- Thermal tend to stick together. Think it as a hard column of air mass. The leeside of the thermal causes turbulence.
- When hitting a thermal, always turn upwind (assuming enough terrain clearance). The thermal is an oval shape. It is more probable that you hit the tail section of a thermal first.
- Every thermal is different. Thermal can be on and off. It may not be a static column. It can be an unorganized, group of hot air bubbles.
Active piloting
- Always maintain communication pressure, arm weight pressure.
- Feel the riser, feel the canopy position. active apply pressure to keep it above your head.
- Pitch control: when canopy is behind you, less pressure; when canopy is ahead of you, more pressure. feel the riser and its position. Do not use break pressure to feel wing position.
- Roll control: when rolling to the left, (you are in the left side of the wing. Your left is higher than your right), pull right break and lean to your right.
Do more forward kiting in strong wind, keeping the wing above your head, to practice active piloting.
Use other pilots as information
- Watch what other pilots, birds are doing. Where are they? Are they turning? Are they climbing? If they are climbing, join them, sometimes with speed bar engaged.
Cloud suck
- When entering a thermal with cloud above, always keep the edge of the cloud at 45 degree. That is your escape route. Choose the edge with blue sky (less clouds)
Situation Awareness
- Do not assume everyone would respect the right of way. Actively looking around. Who is “that guy” that no one want to thermal with.
Frontal or asymmetric collapse
- Hands up.
- Maintain heading
- Look up, check what happened.
- On A or B wing, it shall recover automatically.
- If not, pump break.
- Small collapse or wing tip flaps are OK. maintaining communication pressure and active piloting.
References:
Thermal theory
https://www.ushpa.org/public/articles/2001-thermals-part-one-collectors-wicks-and-triggers.aspx
How to center a thermal