Unmanned Traffic Jam
To the Federal Aviation Administration, civilian UAVs are the new barbarians at the gate.
- By Douglas Gantenbein
- Air & Space magazine, July 2009
Department of Defense
Above a potato patch in the rolling green hills of southwest Virginia, two small airplanes buzz insistently on an August morning, cutting tight spirals through the misty air. Attached to each wing of the small unmanned aerial vehicles (UAVs) are canister-like traps. What they’re trapping are tiny sporangia. Potato-blight sporangia.
Elson Shields, a professor of entomology at Cornell University in New York, is an expert in using remote-controlled UAVs as a scientific tool, and the researchers on his team are flying the aircraft. He brought the UAVs to this Virginia potato patch, owned by Virginia Tech University, to help university professor David Schmale. Several weeks earlier, Schmale had deliberately infected a crop of red potatoes with sporangia of Phytophthora infestans, the same pest that devastated Ireland’s potatoes in the 19th century, sending a million starving immigrants to the United States, Canada, and Australia.
The field is covered with the blackened, curling leaves of dying potato plants. As the sun warms the air, the tiny sporangia take flight on rising air currents, hopping from one pasture to the next. In a matter of days, they may travel hundreds of miles, but little is known about how they travel, how high into the atmosphere they reach, and how long they remain viable once they’ve taken flight. These are the things Schmale wants to learn. Potato blight is still a threat, with no commercial tuber fully resistant.
Agricultural research is only one of many commercial uses for UAVs. Entrepreneurs across the United States are eyeing them for chores ranging from surveying fields to spotting forest fires to photographing highway accident scenes. But first, UAVs have some hurdles to jump. The idea of the nation’s airspace filled with hundreds of pint-size aircraft—some remotely controlled, some operating entirely on their own as autonomous craft—has the Federal Aviation Administration in a cold sweat. While the FAA has been issuing Certificates of Authorization (licenses to fly, referred to as “COAs”) for UAVs, the permits are just trickling out, not nearly fast enough to meet the clamor for them. “We’re at a standstill because we can’t get COAs,” says Ross Hoag, co-founder of Cloud Cap Technology, an Oregon company that makes control systems for military UAVs and would like to do the same in the commercial sector.
Above the Blacksburg potato fields, Schmale and Shields conduct two sessions tracking the epidemic’s progress. This morning, persistent fog over the nearby New River grounds Shields’ little aircraft fleet. The bright red, yellow, and blue aircraft—built by Shields and his crew—have 10-foot wingspans, weigh 45 pounds, and are powered by 50-cc engines. “It’s like flying a semi-truck,” says Shields, a tall man with a shock of white hair poking out from under a baseball cap. “They’re quite heavy when fully loaded, and they have to be rugged and durable because we often fly from rough airstrips.”
By 10:30 the fog lifts, and things happen fast. Shields spins the UAV’s propeller and the little engine catches. Grabbing a remote control unit, he toggles the controls to steer the craft down its takeoff path in a roughly mowed field. It bounces a few times, then zooms into the air. A second aircraft soon follows. Shields hands the controls to two support staff (“I take them off and land them,” he says), then walks across the field to the planned flight path. In a nearby trailer, a radio downlink feeds computer screens the aircraft’s speeds and elevations. The data will be used to ensure the aircraft fly as consistent a path as possible.
Once the craft are airborne, the doors covering the sporangia traps snap open for exactly 30 minutes. By examining the record of each aircraft’s speed, the researchers can calculate how many cubic yards of airspace it flew through, determine the number of sporangia in the trap, and compute the density of sporangia in the air.
Flying the mission with piloted aircraft would cost much more, but Shields’ fleet of airplanes has its limitations. They require a considerable entourage of operators on the ground: an observer, required by the FAA, to scan the skies for other airplanes, and personnel to change the traps between flights, refuel, and download flight data onto a laptop. And the precision of the UAV’s flight paths—critical to accurate measurement of anything from blight spores to insects (which Shields collects by UAV for his own research)—depends upon the skill of the person managing the toggles.