## Locating Wave Lift ### Visual Indications The best lift is often found just upwind of rotor or lenticular clouds. ![[GFH OLD wave anatomy.png]] ### Searching Techniques In the absence of visual indications of wave, a pilot may need to search for the best lift by trial and error. If the wave remains stationary with respect to the ground, keeping track of the best lift may simply be a matter of noting position. The horizontal location of the best lift may change with altitude, or the wavelength may change over time; in this case, searching upwind first is usually best. Searching too far upwind usually does not encounter excessive sink, and makes a transition further downwind easier, while searching downwind may result strong sink and a strong headwind while trying to re-contact the lift. ## Techniques ### Maintaining Best Lift ![[GFH maintaining wave.png]] Ideally, the wind speed matches the glider's minimum sink speed, and the glider is able to maintain a position in the best lift without altering speed or maneuvering. If the wind speed is close to the glider's speed, only small changes in speed may be necessary. Very strong winds may require the glider to fly considerably faster than minimum sink, however, this is is necessary to avoid flying downwind into the sink. If the glider's speed is slightly faster than the wind speed, gentle turns may be needed to crab and avoid drifting too far upwind. Weaker winds may require a pilot to crab back and forth along the areas of best lift, or even fly turning maneuvers to remain within the lift; all turns should be made into the wind, and care should be taken to avoid excessive downwind drift. ![[GFH wave weak winds.png]] ### Transitioning Waves Transitioning from the secondary to primary wave, tertiary to secondard wave, etc is possible, but must be done with care. A pilot should anticipate **significant** sink on the downwind side of each wave, and choose a sink penetration speed accordingly. Contacting rotor is a possibility, so a pilot must also be ready to reduce speed promptly if turbulence is encountered. ![[GFH transitioning waves.png]] ## Additional Concerns Wave soaring often involves flight at high altitudes; as such, the pilot must address some additional concerns: - Hypoxia; oxygen equipment is required by §91.211(a) above 12,500ft for more than 30 minutes, above 14,000ft, and is recommended above 10,000ft - Aviation DCS; is possible above 18,000ft, and a significant risk above 22,000ft - Extremely cold temperatures will likely be encountered - Class A airspace exists beginning at 18,000ft MSL; unless a "wave window" has been previously coordinated with ATC - Glider Vne decreases as altitude increases ## Additional Resources [<iframe width="560" height="315" src="https://www.youtube.com/embed/whCkAGH7thU?si=pCFU3Pax7ERa38Em" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe>] [<iframe width="560" height="315" src="https://www.youtube.com/embed/X6VBOKvuFKw?si=CCuXPFpkZe_cwRZ8" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe>]