Slope soaring

Slope Soaring (also commonly referred to as Slope Gliding or Sloping) is an activity whereby a pilot flys an unpowered radio-controlled plane relying entirely on slope lift to keep the plane in the air. Simply, slope lift is the updraft produced by wind blowing at a (near) perpendicular angle to the face of a steep slope (see image). File:Slope lift.jpg

The basic requirements

Slope soaring requires be a hill with a prevailing wind on the face. This wind will create a lump of rising air directly in front of the hill which may extend quite a distance outwards from its face. The wind will take the shape of a wave which resembles the shape of the hill. The higher the hill the better the standing wave of air. This wave (henceforth known as slope lift) is used to keep a radio-controlled glider airborne. The glider is always descending but the slope lift is rising faster than the glider sink rate .

Aircraft type and materials

A huge range of slope soaring gliders are available. These range from small planes with under 36 inch wingspans, to planes with 4 or 5 meter wingspans.

Slope gliders come in many different shapes:

• Flying Wings (also sometimes called "planks")
• Scale Gliders: planes designed to look like full size sailplanes
• PSS (Power Scale Soarer): planes that are as close to possible a scale replica of a traditional, powered plane.
• Scratch-builts: customed designed planes that are not meant to resemble any real-life aircraft

Slopers can also be build from many different materials:

• EPP (Expanded Poly Propylene): a tough, durable foam that is very popular for it's resiliency
• Balsa: a very light wood. balsa planes are very brittle and are usually built-up (meaning wings are created with ribs etc.)
• EPS (Expanded Poly Styrene): a more brittle type of foam that is commonly used to build light wings. Is usually sheeted (covered) with balsa.
• Composite: high performance materials such as carbon etc.

Different styles of flying

Depending on the wind conditions and the type of plane being flown, there are a number of different styles of flying. Some of these include combat, Thermal, Ridge racing, and Dynamic Soaring to name a few.

Combat is usually flown with EPP models as mentioned before due to their impact resistance. Each pilot tries to knock the other's aircraft physically out of the air. A "kill" is scored only when the opponents aircraft hits the ground. If a hit occurs and each aircraft recovers and remains airborn the hits generally do not count. Often this activity includes extreme maneuvers and aerobatics.

Thermal, while not technically slope soaring, is often combined with other activities. Thermal lift, as opposed to slope lift, is created form a column of hot, rising air. Using the slope to launch a thermal glider has produced new terminology, slermal, which is a mixture of both slope lift and thermal activity away from the hill face.

Ridge racing (or pylon racing where markers are present) is essentially using the slope lift to race along the "lift zone" -- generally parallel to the slope. This can either be done MoM (man-on-man), in heats of 3 or 4, or simply against the clock (timed).

Dynamic soaring is a relatively new style of flying whereby the backside of certainly slopes can be utilized to create amazing speeds.