LINCOLN, Neb. (AP) — Researchers at the University of Nebraska-Lincoln are developing an unmanned aircraft that can drop flaming balls to help firefighters safely set prescribed burns.

A prototype has been developed that can be programmed to fly over a certain area and drop balls that will ignite several seconds later.

Firefighters already used the balls that contain a powder that will ignite several seconds after being injected with liquid glycol, but they are dropped from manned aircraft that are often considered too costly or expensive to be used.

Indoor tests of the prototype have been encouraging, but researchers probably won’t get a chance to try their drone in the field until next spring.