The US Air Force and army have moved towards buying unmanned aircraft systems to ferry small cargo loads into dangerous or remote areas.
The services are planning to attend an "unmanned cargo aircraft day" on 17 November hosted by the Air Mobility Command at Scott AFB, Illinois.
Both have asked contractors to submit concepts for a vehicle than can autonomously deliver between 1,360kg (3,000lb) and 2,270kg of "critical supplies", such as ammunition, water and food.
The UAS must also be able to take off and land within a 150m (300ft) space, and travel to a drop-off point at least 925km (500nm) away with a full payload, according to a USAF acquisition document released on 28 September.
The solicitation also invites companies to submit concepts based on gliding to a drop-off point after being air-launched by a powered aircraft. Another possible concept includes a ship-based vehicle.
The meeting follows a decision by the US Navy and Marine Corps to demonstrate two cargo unmanned systems that could be deployed in 2010. The Boeing A160 Hummingbird and Kaman/Lockheed Martin K-Max were selected in August to complete the demonstration in the first quarter of 2010.