A helicopter does not simply pass through the air and leave it still behind. Its rotor system throws a powerful, rotating wake into the surrounding air. The linked video is a useful visual reminder: the disturbed air does not behave like a neat stream. It rolls, breaks, twists, descends, spreads sideways and can remain hazardous long after the helicopter has moved on.

For paraglider pilots, this matters because our wings are light, slow and highly exposed to small-scale air movement. A wake that may be manageable for a powered aircraft can be violent for a paraglider. Wake turbulence can impose sudden roll, pitch changes, collapses or loss of control. Any aircraft using a fixed or rotary airfoil to generate lift creates wake vortices, and that these can vary in strength and persistence.  

Helicopter wake is especially deceptive near launch sites, landing fields, ridges, valleys and confined areas. Rotor downwash can hit the ground, spread outward, rebound off terrain, and interact with wind, thermals, trees, buildings and slope lift. The result is not just “wind from the helicopter”; it is a moving patch of unstable, rotating air.

The important point is persistence. Wake vortices can remain for several minutes, especially in light wind, stable air or sheltered terrain. Safety guidance commonly refers to wake vortices persisting for three minutes or longer in some conditions.   This means that “the helicopter has passed” does not mean “the air is safe”.

For paraglider pilots, the practical rule is simple: give helicopters a wide berth in both space and time. Avoid flying through the path a helicopter has just used. Be especially cautious downwind, below, behind, or near the hover area of a helicopter. If a helicopter has crossed a ridge, launch, landing approach or thermal source, assume the air may remain contaminated for several minutes.

If you are on launch, wait. If you are airborne, turn away early and create separation. If you are low, near terrain, or already in active air, treat the wake as a serious hazard rather than a curiosity. A paraglider has very little energy margin when close to the ground.

The safe mindset is this: a helicopter’s wake is invisible weather created by the aircraft. You may not see it, but your wing will feel it.