SEATTLE (AP) -- A doctor who had missed his flight called police three times to tell operators there was a bomb aboard the plane, forcing its return to Seattle-Tacoma International Airport, federal prosecutors said.

Kou Wei Chiu, 31, of Bellevue, Tennessee, made an initial court appearance Thursday afternoon, where he was charged with making a false threat against an aircraft. A detention hearing was set for Friday.

According to an FBI affidavit filed in support of the complaint, Chiu admitted that he used a payphone at Seattle-Tacoma International Airport to call emergency services number 911 three times after he arrived at the gate too late to board his Northwest Airlines flight Wednesday. "Flight 980 Memphis. There may be a bomb on board," Chiu was quoted as telling the emergency operator.

"After his first phone call, he looked outside at the plane and saw that his call had had 'no effect,"' FBI agent Gary France wrote. "He made a second phone call and noticed that this call too had no effect. This led to the third call.

"Chiu stated that he made the calls thinking that the airline 'would ground the plane for a couple of hours,' because bomb threats are taken seriously. When asked how he thought other passengers might react when they overheard his calls, he conceded that he thought 'they would be traumatized,"' the affidavit said.

Chiu also told investigators that he had been off his antidepressant medication in recent days, France wrote.

His lawyer said Thursday that Chiu is eager to return to his family.

The plane was in the air by the time Chiu was arrested, and it was brought back to the gate and grounded for several hours while authorities determined the threat to be a hoax. Northwest estimated that it lost $70,000 (euro51,000) in fuel, gate fees and other expenses.

The plane arrived in Memphis late Wednesday night.