A US Airways employee and a passenger were arrested yesterday for trying to sneak an unloaded gun onto a flight from Philadelphia to Phoenix, the FBI said.

Roshid Milledge, 38, a customer-service representative for US Airways, allegedly helped Damien Young, 29, get a 9mm pistol onto Flight 1195, which was scheduled to depart at 7:10 a.m.

"This investigation represents an isolated incident, involving only these two individuals," FBI Special Agent in Charge Janice K. Fedarcyk said.

Young apparently wanted to take the gun to Phoenix and had no intention of taking it out during the flight, the FBI said.

Both men are charged with illegal possession and concealment of a dangerous weapon on an aircraft.

Young took a laptop-style bag through security, then met Milledge at the customer-service counter, where Milledge gave him a similar bag containing the gun, an FBI affidavit said.

Another passenger on the flight witnessed the switch and alerted an airline employee, the affidavit said. The passenger noticed that Milledge appeared nervous.

An airline manager boarded the plane and asked Young whether he had switched carry-on bags and Young said no, the affidavit said. The plane began to taxi to the runway but was ordered back.

A US Airways regional manager for corporate security and a Philadelphia police officer boarded the plane and removed Young and the bag.

Young admitted there was a gun in the bag and later told FBI agents that he lived with Milledge in South Philadelphia and was moving to Phoenix and wanted to take the gun with him.

The flight took off around 10:30 a.m. and arrived safely in Phoenix.

Noting that a passenger observed the switch, Fedarcyk said: "These circumstances serve to underscore the importance of vigilance on the part of all Americans to help keep our society and our citizens safe."

"We are cooperating with investigators fully and take security considerations very seriously," Morgan Durrant, senior manager of corporate communications for the airline, said in an e-mailed statement.