Two people died and two others were injured after a helicopter and a gyrocopter collided in midair on Saturday at a Wisconsin airport that was hosting an air show, the authorities said.
The collision occurred around noon at Wittman Regional Airport in Oshkosh, Wis., where the Experimental Aircraft Association AirVenture show was being held, showcasing aerobatic displays and aircraft from different eras in a weeklong event.
Dick Knapinski, a spokesman for the association, said in a statement that the victims were attendees of the show and that their aircraft — a Rotorway 162F helicopter and an ELA 10 Eclipse gyrocopter — were “not involved in the air show.”
The identities of the victims were not released by officials on Saturday. Mr. Knapinski said he was not sure whether both of the people who died had been flying in the same aircraft.
The collision did not occur during the air show, a spokesman for the National Transportation Safety Board said.
The two people who were injured were taken to a hospital and were in stable condition on Saturday evening, according to the Winnebago County Sheriff’s Office.
It was not immediately clear what may have led to the collision.
The N.T.S.B. said an investigator was on the scene Saturday to examine the aircraft, collect air traffic communications and interview witnesses.
The ELA 10 Eclipse gyrocopter — which looks like a small helicopter and flies at slow speeds — is described by its manufacturer as an “exclusive gyrocopter, with refined lines, high performance.”
The Rotorway 162F helicopter was described in 2019 by AVWeb, an aviation news outlet, as a small kit-built aircraft that costs $60,000.
The AirVenture show typically draws about 500,000 visitors each summer to Wittman Regional Airport, which becomes a hub for aircraft and aviation enthusiasts who travel from about 80 countries to see more than 10,000 aircraft, including amateur-built, ultralight and vintage military planes.