What Is Cloud Suck? Understanding the Dangerous Phenomenon Behind Paraglider Incidents

A Chinese paraglider has captured widespread attention after narrowly surviving a perilous flight incident high above the Qilian Mountains, where he was unexpectedly swept up to an altitude of 8,598 meters—without any supplementary oxygen—by a powerful atmospheric updraft known as "cloud suck."

The pilot, whose face was unprotected and whose body became encrusted in ice crystals during the flight, managed against the odds to maintain consciousness and keep control of his glider despite rapidly deteriorating conditions. Upon eventual safe landing, he recounted symptoms of acute hypoxia and severe numbness in his hands due to subzero temperatures and extremely thin air at such heights.

Understanding the phenomenon: Cloud Suck
Aviation expert Wang Yanan explained that the root cause of the incident is a rare but dangerous meteorological event called cloud suck. This occurs when paragliders get too close to towering cumulonimbus clouds, which generate intense updrafts that can force air—and anything caught in it—dramatically upward at high speed.

“This kind of ascent carries serious risks,” Wang said in an interview with Chinese media. “Once inside the cloud, the pilot may encounter extreme cold, a lack of oxygen, violent turbulence, or even lightning strikes. At extremely high elevations, these dangers are greatly magnified, making cloud suck potentially fatal.”

Collision risks at commercial flight altitudes
The extraordinary altitude reached during the incident—nearly 8,600 meters—raises additional safety concerns. According to Wang, this brings paragliders alarmingly close to the cruising level of commercial aircraft, which typically fly between 9,000 and 12,000 meters.

“If the flight area overlaps with civil aviation routes, a paraglider could suddenly enter protected airspace, presenting a major safety hazard,” Wang warned.

In China, all paraglider flights require prior approval from aviation authorities, reflecting strict national regulations. However, relying on powerful updrafts like cloud suck adds a layer of unpredictability and risk that is strongly discouraged within the sport.

Zhao Jingwu, an associate professor at Beihang University’s Law School, outlined the legal and practical implications of such events.
“Passenger jets travel at extremely high speeds. A small object like a paraglider is nearly impossible for pilots to see or steer away from, especially since many onboard radar systems are not calibrated to detect such small targets. A collision at these altitudes would almost certainly be catastrophic,” Zhao said.

China’s unified airspace management
China maintains a strictly controlled national airspace system, divided into several classes based on altitude and usage:

• Class A: Above 6,000 meters; reserved for commercial and long-distance flights, subject to stringent instrument flight rules (IFR) and continuous air traffic control.
• Classes B–E: Varying degrees of oversight, also requiring registration and coordination with authorities.
• Classes G and W: Less restricted, generally used by general aviation, but still governed by strict reporting and safety obligations.

Violations or unplanned penetrations of controlled airspace are regarded as serious infractions, with potentially severe consequences for both pilots and air traffic.

The recent incident over the Qilian Mountains serves as a dramatic reminder of both the thrill and the hazards of extreme paragliding. While the pilot survived this extraordinary brush with danger, experts urge against similar attempts—emphasizing the need for proper equipment, such as oxygen supplies, and rigorous adherence to airspace regulations to ensure the safety of all airspace users.