The military scrambled fighter jets, and the two sonic booms from the Air National Guard F-15s startled many people throughout the Puget Sound area.
The Cessna 180 float plane was flying to a seaplane base on Lake Washington, next to Seattle, from Lake Chelan in Eastern Washington, said passenger Laura Joseph, of Normandy Park. She told The Associated Press that neither she nor the pilot, Lee Daily, knew about Obama's visit or the air restrictions that accompany such a high-profile trip.
The Secret Service interviewed Daily after he landed at Kenmore Air on the north end of the lake, which had been shut down for the duration of the presidential campaign stop.
Kevin P. Casey, AP
The military scrambled fighter jets on Tuesday after a float plane violated the airspace around Air Force One, seen here taking off from Boeing Field-King County International Airport near Seattle.
North American Aerospace Defense Command spokesman John Cornelio said the civilian aircraft had left the restricted area before the two jets arrived from the Portland, Oregon-based 142nd Fighter Wing and that there was no intercept. He confirmed the jets produced the sonic booms.
Joseph said she saw an F-15 outside the window as the plane approached Seattle.
"I saw a jet, just a white jet going by," she said. "I thought it was kind of odd to see a military jet."
The fighter only passed by the float plane once and didn't take any other action, Joseph said.
Joseph said she and Daily didn't know anything was wrong until they landed and were told they had to talk to the Secret Service. She also said she didn't hear the sonic booms.
"Oh my God, I can't believe - is this the top news thing?" she said.
Joseph said she and Daily were allowed to leave after being interviewed by the Secret Service and haven't heard anything yet about possible sanctions.
Obama was in Seattle to stump for Sen. Patty Murray on a three-day campaign swing for endangered Democrats. Air Force One was on the ground at King County International Airport/Boeing Field in south Seattle at the time of the incident shortly after 1:30 p.m. The president's plane departed Seattle at 3:47.
The two sharp booms, a few seconds apart, rattled windows in Seattle. Fire and police officials throughout the region said they were swamped with calls.
Oregon Air National Guard Staff Sgt. John Hughel said the F-15s were scrambled by NORAD from Portland International Airport. He said the guard has two fighters on alert at all times to patrol the air space from central California to the Canadian border.
Associated Press writers Phuong Le and Donna Gordon Blankinship contributed from Seattle.