Updated

Two people were killed and two others were critically injured after two small planes collided, then burst into flames at a central Florida airpark Saturday, the Federal Aviation Administration said.

One airplane was apparently trying to land when it crashed into another plane on the ground around 8:30 a.m. at the Arthur Dunn Airpark in Titusville, said Scott Gaenicke, public information officer and division chief for Titusville Fire and Emergency Medical Services.

The collision engulfed both planes in flames, said FAA spokesman Warren Woodberry.

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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 aided 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 in extremely critical condition, Gaenicke said.

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They were flying in a single-engine aircraft, which according to the FAA'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 registered to William E. Hess of Daytona Beach, FAA records show.

Gaenicke said both of the planes involved are considered experimental aircraft.

"They're not like your off-the-shelf, already pre-manufactured (aircraft)," Gaenicke said. "These are home-built type aircraft that one would buy as a kit and put together."

The Experimental Aircraft Association Chapter 866 was hosting a pancake breakfast Saturday morning when the crash occurred.

Larry Gilbert, an association member, said the plane that was landing appeared to lose control and was trying to take off again when it slammed into the other plane.

The plane that was hit exploded on impact, Gilbert said. He called 911 as other members rushed to help the other plane's occupants.

He said the plane that was landing appeared to be a Velocity model airplane — an experimental craft with large V-shaped wings and a propeller in the back and smaller wings on the nose.

It was difficult to determine the exact models of both planes, he said. "They were so totally destroyed."

Investigators from the FAA arrived at the airport, which remains closed, to begin their investigation and the National Transportation Safety Board officials were on their way.

The air park is an uncontrolled air field and doesn't have a control tower, Gaenicke said.