The US Department of the Interior could begin using unmanned air vehicles to battle forest fire within a year based on a recent demonstration in which Kaman Aerospace and Lockheed Martin doused controlled burns with an optionally piloted K-MAX helicopter.

During a 5 November demonstration, an optionally manned version of the K-MAX completed eight firefighting scenarios at Griffiss International Airport in upstate New York designated by the Federal Aviation Administration as an unmanned air vehicle test site.

During a 4h window, the helicopter performed autonomous fire suppression operations including collecting and dropping 2,270kg (500gal) of water on controlled burns without a pilot in the cockpit, says Dan Spoor, Lockheed’s vice-president of aviation and unmanned systems.

“We also demonstrated the ability to build fire lines, which means sequentially dropping water in front of the fire to create a firebreak,” Spoor says.

The aircraft was able to drop 659l or 10,900kg (24,000lb) in an hour, the equivalent to a single Boeing 747 load, says Greg Steiner, president of Kaman Aerospace.

Also on hand for the test was a Lockheed Indago quadcopter, which fed information to the K-MAX ground control operator. The small UAV would be launched by a firefighter on the fire line to provide situational awareness and to designate a target for the K-MAX to douse.

Manned versions of the K-MAX already are used for firefighting missions, as well as construction, logging and humanitarian disaster relief.

“Optionally piloted versions build on this baseline,” Steiner says. “They can be flown as a manned version during the day and then unmanned during the night to support 24h firefighting.”

The K-MAX served a 33-month deployment in Afghanistan during which a pair of the aircraft flew 2,000 combat resupply missions and delivered 4.5 million tons of cargo to Marines at forward operating bases.

That success inspired Lockheed and Kaman to look for civil applications for unmanned and autonomous resupply, Spoor says.

“That search led to a meeting with the Department of the Interior to look at K-Max for supporting firefighting,” Spoor says. The department, which oversees all federal land within the United States, is interested in fielding a K-MAX on a fee-for-service basis as early as the 2015 wildfire season, pending more extensive testing, Spoor says.

In Afghanistan, the airspace was uncongested and wholly occupied by US military aircraft, which cleared the way for unrestricted UAV flights including the thousands of unmanned K-MAX resupply missions. The FAA forbids unmanned aircraft to fly within the US national airspace without a certificate of authorisation, except for recreational purposes.

Kaman and Lockheed are working with the FAA to determine how the aircraft could fly over wildfires. Airspace over active firefighting operations already is restricted to commercial flight, potentially allowing for the K-MAX to fly unmanned with a special permit, Steiner says.

Future testing will include programming flight management systems to deal with unusual wind conditions created by a wildfire. One of the two helicopters deployed to Afghanistan is undergoing repairs after an unexpectedly strong crosswind caused it to crash.

Only two optionally manned K-MAXs are available for firefighting, including the undamaged example recently returned from Afghanistan. The other belongs to Kaman. Two more will be available in mid-2015, including the repaired veteran of Afghanistan and one owned by Lockheed that will be retrofitted to allow remote piloting, Spoor says.

A couple dozen manned versions are also available for retrofit. If demand allows, Kaman could reopen its production line and have new-build aircraft rolling off by 2016, Steiner says.