BUFFALO — An airline pilot is accused of trying to board a Buffalo-to-New York City flight with a loaded revolver in his bag, and federal authorities believe he’d been flying with it for two days.

The US attorney in Buffalo charged 52-year-old Brett Dieter of Barbersville, Va., with possessing a concealed .357 Magnum, which a screener spotted before he boarded yesterday at Buffalo Niagara International Airport. The Piedmont Airways employee was to pilot a US Airways-contracted flight to La Guardia Airport.

Investigators believe Dieter had been flying with the weapon since Wednesday, when he flew from Charlottesville, Va., to New York City without having his bag X-rayed. He’d made seven flights since.