Tampa, Fla. ? An experimental plane that may have been having trouble landing struck another that was taxiing at an airfield Saturday, setting both on fire and killing two people, authorities said. Two people were critically injured.

The plane trying to land crashed into another on the ground around 8:30 a.m. at Arthur Dunn Airpark in Titusville, said Scott Gaenicke, spokesman and division chief for Titusville Fire and Emergency Medical Services.

Both planes were single-engine and amateur-built, officials said.

An Experimental Aircraft Association chapter was hosting a pancake breakfast at the airfield, east of Orlando and about 110 miles northeast of Tampa.

The plane on the ground appeared to be taxiing to a ramp area when the other plane slammed into it. Two people who were in the plane that had left the runway were killed, authorities said.

The other plane cartwheeled for about 100 yards before landing belly-up on a grass median at the airport. Bystanders helped two people who were in that plane, which also caught fire. They were flown to Orlando Regional Medical Center with severe burns.

One of the survivors is in “grave” condition, and the other is extremely critical, Gaenicke said.

They were flying in a single-engine aircraft that according to the Federal Aviation Administration’s online aircraft registry is registered to Christen Air Inc. in Wilmington, Del., Gaenicke said. A telephone listing for that company was not immediately found.

The other plane was a single-engine RV-8 aircraft.