[chris]

A Boeing 747 used as a backup Air Force One, trailed by an Air Force F-16 fighter jet, flew low over Lower Manhattan on April 27, 2009, panicking workers and flooding 911 lines on both sides of the Hudson River.

The flight was part of a Defense Department photo shoot meant to update official file images of the presidential aircraft. Neither the public nor most city officials had been told in advance, and the low pass near Ground Zero revived memories of the Sept. 11 attacks for people who saw or heard the planes.

Workers evacuated buildings including the New York Mercantile Exchange and the Wall Street Journal's offices in Lower Manhattan. Across the river in Jersey City, New Jersey, callers flooded the Hudson County 911 center. One caller told a dispatcher it looked like the aircraft was flying into a building and that people had run outside; the county released the recordings the next day.

The Federal Aviation Administration said it had authorized the flight near the Statue of Liberty but told local law enforcement not to disclose details to the public. New York City Mayor Michael Bloomberg called the flyover "ill-conceived" and a waste of taxpayer money, and President Barack Obama said he was furious over the episode and ordered a review of how it had been approved.

The Air Force later estimated the mission's cost at $328,835 in fuel, personnel and maintenance expenses. Louis Caldera, director of the White House Military Office, had approved the flight and publicly apologized for the panic it caused. He resigned May 8, 2009.