The US Army has expanded its early search for a future unmanned cargo aircraft to include concepts offering twice the speed of conventional helicopters.
The army's Logistics Innovation Agency (LIA) has asked contractors to submit ideas for a vertical take-off and landing (VTOL) aircraft that could deliver cargo autonomously.
The unmanned, VTOL aircraft must fly faster than 250kt (462km/h), or at least 70kt faster than the Boeing CH-47 Chinook, as stated in LIA's request for information.
The agency is also looking for aircraft concepts that can adapt to any weather in the air or on the ground. It should also be able to carry 2,670-3,630kg (5,000-8,000lb).
Most impressively, perhaps, is a design attribute for a VTOL aircraft that could hover at almost any altitude. The aircraft should be able to take off and land at 12,000ft (3,660m) when the outside temperature is 35°C (95°F), the LIA stated.
The request for information is intended for planning purposes, and comes about seven months after the army's aviation community asked industry for information about a more near-term aircraft that could do the same job.
The medium-range multi-platform concept was unveiled last June, calling for the acquisition of a vertical take-off and landing aircraft to serve in a variety of combat, surveillance and airlift roles.
Two months later, the army agreed to join the analytical phase of a similar programme initiated by the US Navy. The medium-range maritime unmanned aircraft system requirement was expected to attract bids based on the Boeing A160 Hummingbird, Kaman/Lockheed K-Max and the Northrop Grumman/Bell Helicopter Fire-X.