The US Air Force decided to end the second phase of a year-old experiment with light attack aircraft early, due to the fatal crash of a Sierra Nevada/Embraer A-29 Super Tucano on 22 June.

The suspension ends a flying evaluation of the Super Tucano and the Beechcraft AT-6 Wolverine two weeks before a scheduled public demonstration at Holloman AFB, New Mexico on 19 July.

The public event is postponed to a date that will be announced later, the service said.

“A combination of sorties flown during [the] light attack experiment phase I [last year] and [the] May-June portion of [the] light attack experiment phase II generated sufficient data to meet experimentation objectives,” the USAF says. “Even though the flying part of the experiment is concluded, developmental test, maintenance and sustainment data collection portions will continue as necessary to inform an acquisition decision.”

The USAF plans to use data gathered from the experiment to decide whether to buy potentially hundreds of light attack aircraft. The hope is these fighters could be cheaper alternatives for certain missions to using aircraft such as the Lockheed Martin F-35 and Boeing F-15.

The service said it did not have a timeline for when it would pick a winning aircraft.

The trials were suspended after a US Navy pilot died and another crew member suffered minor injuries after both ejected from an A-29 about 56nm (105km) north of Holloman AFB at the Red Rio Bombing Range last month. The crash would not harm Sierra Nevada/Embraer's chances of winning the competition, the USAF said.

The USAF said it didn’t have any new information on the cause of the aircraft mishap, which remains under investigation.