Relatively confined areas of good lift, and close proximity to terrain, present unique hazards during ridge soaring. To mitigate the associated risks, rules and procedures have been developed to ensure separation from the terrain and other aircraft. ## Rules ![[GFH ridge rules.png]] ### ALWAYS turn away from the ridge - obvious: turning away from the terrain is safer - groundspeed (and therefore [[Radius of Turn]]) are greatly increased if turning downwind toward the ridge - even if above the ridge, overshooting the turn will place the glider in heavy sink on the downwind side ### Approach the ridge from a 45° angle on the upwind side - approaching a ridge from the downwind side will involve flying through heavy sink and should not be attempted at low altitude - approaching the ridge perpendicular on the upwind side will involve the highest groundspeed, largest [[Radius of Turn]], and highest rate of convergence, with a risk of overshooting and colliding with the ridge - approaching from a 45° angle on the upwind side allows for a manageable rate of convergence, and an easy escape if the pilot elects to abandon the entry for any reason ![[GFH approaching ridge.png]] ### Do not fly directly above or below another glider - most gliders have [[Glider Visual Scanning and Collision Avoidance#Blind Spots]] directly below the cockpit; high-wing designs will also have a blind spot above and to the side of the cockpit ### Pass another glider on the ridge side - anticipate other gliders turning away from the ridge, so plan to pass on the ridge side - if inadequate space exists between the other glider and the ridge, either reverse course or fly upwind and rejoin the lift, as traffic permits ### When converging, the glider with the ridge to the right has the right of way - per §91.113(e), aircraft converging head-on should both alter course to the right to avoid collision; this is impractical and unsafe for the glider with the ridge on the right side, so the glider with the ridge on the left side should maneuver right, upwind and away from the ridge ### ALWAYS have an escape plan - weather may change, unexpected loss of lift may occur, or traffic conflicts may appear suddenly; ALWAYS have an escape plan to abandon the ridge with a safe landing option available ## Additional Hazards ### Terrain Irregularities - terrain irregularities result in complex three-dimensional flow patterns, and adjacent areas of strong lift and sink; avoid protrusions (ie spurs) on the downwind side, and when in doubt, higher speed provides an extra margin for safety ![[GHF spur.png]] ### Obstructions - the risk of colliding with an obstruction is always present at low altitudes; check aeronautical charts and talk to local pilots before flight, and **always** assume that there are wires between any poles or buildings that you see ### Thermal Upset - in unstable conditions, the presence of thermals can upset a glider; this can be particularly hazardous if the upset rolls the glider toward the ridge, so when in doubt, higher speed provides an extra margin for safety