Flight Crew Commercial
Flight Crew Last 90 Days 24; Flight Crew Total 826; Flight Crew Type 826
Time Pressure; Confusion; Distraction; Situational Awareness; Workload
Ground Event / Encounter Loss Of Aircraft Control; Inflight Event / Encounter Weather / Turbulence
Flight Crew Regained Aircraft Control; Flight Crew Became Reoriented
Weather; Human Factors
Aircraft X VFR Flight Operations Sight Seeing Hot Air Balloon.Approximately 15 minutes into the flight; I descended near the [the] River upstream of the Falls at [the] State Park. A low-level inversion over the river caused the balloon to rise slightly. Shortly after a wind rotor pushed the balloon down over the edge of the falls and back into the cascading water. The mechanical turbulence of this wind was stronger than I have ever experienced. I operated the burners to arrest the descent; gain altitude and ascend out of the gorge. The balloon landed safely 2 miles from the waterfalls. There were no injuries to passengers or pilot and no damage to the aircraft.Since this incident I have spent days reflecting on what occurred; the seriousness of this event; and what I can do differently in the future so that this never happens again. I've reached out to my colleagues for peer pilot review to process this self-critique. I've reviewed the FAA Balloon Flying Handbook. My research and reflection have led me to develop a corrective procedure and make immediate changes to my flight operations. Mechanical wind turbulence- resulting from wind flowing over irregular terrain or obstructions. When the air near the surface of the Earth flows over obstructions; such as irregular terrain; (bluffs; hills; mountains) and buildings; the normal horizontal wind flow is disturbed. As a result; it is transformed into eddies or other irregular air movements. The strength and magnitude of mechanical turbulence depends on: the speed of the wind; the nature of the obstruction; the stability of the air; and the angle at which the wind moves over the obstacle. As the air flows down the leeward side of the mountain; the air follows the contour of the terrain and is increasingly turbulent. This tends to push an aircraft into the side of a mountain. The stronger the wind; the greater the downward pressure and turbulence become. Due to the effect terrain has on the wind in valleys or canyons; downdrafts may be severe.	I flew the balloon too close to an irregular terrain feature; canyon; river and waterfalls where Mechanical Wind Turbulence can be present and at varying levels of severity. I will no longer conduct low level waterfall passages as part of my flight operations. Instead I will approach them at no lower than half the height of the irregular terrain similar to flying over a mountain in a balloon. For example: The Falls in [the] State Park is 100 ft. tall. My flight procedure will be to fly no lower than 50 ft. above the river and falls below. This will insure safe altitude from the effects of mechanical wind turbulence on a hot air balloon.
A Hot Air Balloon pilot reported unexpected wind currents forced the balloon to descend into a waterfall and river but they were able to regain control and climb away to a safe landing area.