Lockheed Martin’s Kaman K-Max unmanned helicopter will return from Afghanistan.

The initial four-month military utility assessment turned into a resounding endorsement of the concept of using unmanned cargo helicopters to reduce the need for convoys and manned-helicopter resupply flights in dangerous territory.

The project has proved the case for autonomous cargo resupply. The surviving aircraft of two deployed in December 2011 to resupply remote U.S. Marine Corps forward operating bases will return to the U.S. soon, after 2.5 years of operations and 4.5 million tons of cargo carried.

Both the Marines and Army are studying cargo unmanned aircraft system programs, the Navy is funding research into advanced autonomous capabilities for resupply helicopters and Sikorsky has launched a program to build a company-funded prototype of an autonomous Black Hawk for the cargo logistics mission, hoping to shape requirements as they firm up.

Sikorsky, in anticipation, plans to develop an autonomous Black Hawk by modifying a retired UH-60A to conduct cargo missions as an optionally piloted or unmanned aircraft. The initiative is a follow-on to the Manned/Unmanned Resupply Aerial Lifter (Mural) cooperative technology demonstration with the Army, and will use systems and software being developed under the company-funded Matrix Technology autonomy program.