ST. LOUIS -- After years of development, Boeing unveiled its prototype for the Navy's MQ-25 Stingray unmanned tanker competition and revealed the air vehicle uses the same engine as the RQ-4 Global Hawk and MQ-4C Triton. Don "BD" Gaddis, MQ-25 program director at Boeing's Phantom Works division, told reporters here April 5 he is pleased the company is using the Rolls Royce AE 3007 engine for its MQ-25 prototype. Boeing is also using an air-refueling pod made by Cobham. The...