WASHINGTON (AP)--A Denver-bound Frontier Airlines passenger jet flew through the restricted airspace above the White House on Monday evening, the Federal Aviation Administration said. The pilot of Flight 819, a Boeing 737, was immediately contacted by air traffic controllers and he acknowledged making an error, said FAA spokeswoman Laura Brown. The plane took off from Reagan National Airport at 6:15 p.m. EST and landed at Denver International Airport. It was monitored after entering the restricted airspace, but no other measures were taken. The airspace above washington is still being patrolled by fighter planes. The standard departure route for planes flying out of Reagan National includes a sharp turn just after takeoff, to avoid the restricted airspace. ``The pilot missed the first turning point,'' Brown said. ``He did manage to go through part of the restricted airspace.'' She said the plane was monitored by ``appropriate security agencies.'' Before the Sept. 11 terrorist attacks, the airport's past flight paths followed the Potomac River, bringing planes close to CIA headquarters, the White House, the Capitol and the Pentagon. Now flights follow a straight line, over some residential areas, rather than along the river. The river routes were intended to reduce noise.