The Associated Press

HAMILTON - A single-engine plane that entered restricted airspace during President Bush's visit to Cincinnati on Monday was escorted to a regional airport by two F-16 fighter jets, officials said.

The pilot, whose name was not released, apparently did not know about the restrictions.

"He said he didn't know what was going on," said Joe Conrad, president of ProAero, the fixed-base operator at Butler County Regional Airport-Hogan Field. "He didn't notice the jets right away and when he did, he didn't know what had happened.

"He didn't file a flight plan, which usually is OK. But it wasn't OK (Monday) because of the president's visit to Cincinnati."

Hogan Field was busier than usual because air traffic was diverted from Cincinnati's Lunken Field, which was shut down during the president's visit. Airspace was restricted within 35 nautical miles of the Cincinnati/Northern Kentucky International Airport, where Air Force One landed and departed.

Secret Service agents interviewed the pilot by telephone while Butler County sheriff's deputies inspected the plane.

The FAA will determine whether to issue sanctions against the pilot.