Longest endurance inside a tropical cyclone by an uncrewed aircraft

The longest survival by an uncrewed aircraft in a hurricane is 105 minutes, achieved by a Black Swift S0 sUAS (small uncrewed air system) which flew into the eye of Hurricane Helene, at the time a Category 1 storm, on 25 September 2024. The air-deployed variant of the S0 is the result of a collaboration between Black Swift and NOAA (both USA). It was deployed into the storm by an NOAA Hurricane Hunter aircraft as it passed between the Yucatan Peninsula in Mexico and the west coast of Cuba.

The Black Swift S0 was deployed from a pneumatic tube that launched it through the bottom of the fuselage of an NOAA WP-3D Orion as it flew over the eye of the hurricane. These tubes were designed to deploy parachute-borne "dropsondes" and have a diameter of 5.12 in (13 cm) and a length of 3 ft (91 cm). This means that any air-deployed drone has to be packed into a cylinder and then unfold itself in flight.

The S0 is a small, 2.75-lb (1.25-kg) twin-propeller aircraft, with folding wings that extend to a deployed wingspan of 3 ft (91.4 cm) on launch. It carries instruments to measure wind-speed, temperature, barometric pressure, humidity and magnetic fields, as well as an accelerometer and gyroscope. Impressively, the S0 is around a tenth of the size of the previous holder, the Altius 600.

The following day, another S0 UAS achieved the longest communications range, sending data back to its deployment mothership from a distance of 191 mi (307 km). Long range transmissions are useful because they allow meteorologists to collect data from the most dangerous parts of the hurricane, while keeping their own aircraft at a safe distance.

The key advantage of powered UAS is that they allow for the collection of continuous observations from inside a storm. Before these drones were an option, NOAA scientists had to rely on dropsondes (small packages of sensors that are dropped into the storm) but these provided only a momentary snapshot of conditions at different altitudes as they plummeted down to the surface.