DARPA heavy lift challenge ends with winner at a 3.84:1 payload to weight ratio

Avidrone Inc. won DARPA's Lift Challenge with the Katana, a conventional single-rotor helicopter that achieved a 3.84:1 payload-to-weight ratio by carrying 51 kg while weighing only 13.3 kg. Because no team reached the required 4:1 ratio, all prize money was halved, with Avidrone receiving $1.25 million instead of the advertised $2.5 million. The winning design used battery-electric propulsion and outperformed 60 competing teams across seven days of competition, proving that conventional helicopter physics—with a single large rotor at low disc loading—was more efficient than experimental multirotor designs.