TEMPEST TRIUMPH: A small unmanned aircraft was able to overcome various FAA hurdles this spring to make a successful data-collecting flight into a thunderstorm with tornado potential. Image: University of Colorado at boulder
Unmanned aerial vehicles (UAVs) are no longer just gizmos in a geek's garage or military tools that fly reconnaissance missions considered too dangerous for humans. They are increasingly being used for scientific study. And this spring, a UAV dedicated to research science made aerial history.
On May 6, a diminutive aircraft called the Tempest was the first official UAV to intercept a supercell thunderstorm, the type of storm that produces tornadoes. The aircraft and its crew of engineers from the University of Colorado at Boulder (C.U.–Boulder) and meteorologists from the University of Nebraska–Lincoln are a critical part of an armada of 100 storm-chasing scientists conducting the largest study of tornadoes in history. The two-year field experiment known as VORTEX 2, running from May 1 through to June 15 this year, will help scientists better understand when and how tornadoes form. Teams travel across the Midwest in tight formation chasing and surrounding tornadic storms to measure wind speed, temperature, humidity and pressure using mobile radar trucks, anemometers, disdrometers and balloon launchers.
Added to this list, the Tempest is designed to take center stage, flying into the rear flank of supercells, 150 to 300 meters aboveground—a sweet spot for gathering data that are inaccessible to the current instruments or any manned aircraft. Now that it has made its maiden data-gathering flight, the Tempest stands ready to continue this work for the duration of this tornado season.
But it's not that simple: Federal Aviation Administration (FAA) regulations restrict the Tempest from freely flying throughout the range of "tornado alley"—the area in the U.S. between the Rocky and Appalachian mountains. Currently, the researchers can only work within about 58 small grids of land, each about 1,000 square kilometers in area in northeastern Colorado and portions of Kansas and Nebraska. Getting flight clearance in just these areas required three years of coordination with the FAA. The researchers had to file 60 applications in order to be waived from having to comply with all the rules specific to manned aircraft.
When Brian Argrow, director of the University of Colorado Research and Engineering Center for Unmanned Vehicles, announced that he wanted to apply for the entire area stretching from central Nebraska to the Texas panhandle—an area that sees a concentration of twisters—FAA members responded with an audible gasp. Currently the FAA has a freeze on further applications to fly.