Police: Angry Ex-Girlfriend Triggered US Airways Bomb Hoax The Philadelphia to Dallas plane was determined to be safe and explosive-free.

Sept. 6, 2012  -- A bomb hoax in Philadelphia that turned a Dallas-bound flight around and led to a full-scale SWAT response was apparently triggered by a spiteful ex-girlfriend who participated in a cruel joke on her former beau who was aboard the US Air flight, police told ABC News.

A man who called police said the passenger was armed with liquid explosives, police said.

According to authorities, Christopher Shell, a salesman in his 20's who travels between Philadelphia and Dallas, had no explosives and is cooperating with authorities. He appears to have been the victim of a cruel joke.

When asked how Shell reacted when police took him off the plane, Philadelphia Police Chief Inspector Joseph Sullivan said at a news conference, "He was obviously very alarmed as I would be if heavily armed police entered a plane to take me off...he was certainly stunned."

However, in an unlikely coincidence, Shell had been sped through security by a friend at the airport and posted a message to his Facebook page that getting through security had been a breeze.

The note would have been innocuous in any other circumstance, officials said. In the context of the phoned-in threat alarms went off and bomb techs, cops, FBI agents and K-9 dogs descended on the flight and conducted a full search.

The ex-girlfriend and a man believed to be a current boyfriend are now in custody, sources said. According to sources, they appear to have perpetrated the hoax bomb threat and are being questioned by federal authorities in Philadelphia. Sources said they have not sorted out what their individual roles were. Neither the FBI nor the U.S. Attorney in Philadelphia would comment. No charges have been brought against anyone at this time, sources say.

"This is no joke," Sullivan said. "These will be federal charges...they're going to be very serious charges."

He said authorities did not yet have a motive for the hoax.

"It's just an incredibly foolish and irresponsible thing to do," he added. "And bottom line, it's criminal."

Passenger Kurt Weber, 54, was sitting in seat 4D when the incident unfolded. Before the plane turned around, Weber said a pilot came over the intercom and said they were having "trouble with instruments" and needed to turn around. Weber is a consultant for the Archery Trade Association and was on his way to a trade show,

Upon landing, Weber saw several emergency and police vehicles racing out. The girl sitting next to him said, "I'm sure glad we are not going where those guys are going." Moments later, the plane taxied near the emergency vehicles and authorities boarded the plane.

"It was like Seal Team Six," Weber said. "The SWAT team from Philly, they were pretty awesome."

"These guys entered from the rear of the plane," he said. "Next thing I know, it almost sounded like a stampede. Here are four Philadelphia SWAT guys, all in black with laser sights on their weapons, weapons drawn and focused on this guy."

Weber said that the team had the man handcuffed and on the ground "in seconds."

"Then the bomb techs got on the plane and the SWAT team took positions throughout the plane and authorities explained clearly to the passengers what had happened that led to the raid," he said. "The pilot was calm, the flight attendants were calm and helpful."

Philadelphia police received a call around 7 a.m. from a person stating that a specific individual had explosive liquid on him and was attempting to get it past TSA and onto the Dallas flight.

Authorities later discovered that the person implicated on the tip call was on the flight to Dallas that had departed at 7:39 a.m. and ordered it to return, according to ABC News' Philadelphia affiliate WPVI.

The man was being questioned, his luggage was searched and no explosives were found. No explosives were found on the plane.

All 69 passengers and five crew members on flight 1267 are safe.

"As soon as we had the situation on the plane secure, I did speak to all the passengers and they were briefed as to what was going on," Sullivan said. "All the passengers were extremely cooperative and very understanding, despite the fact that they were all shaken up."

Philadelphia police officers, FBI bomb technicians and SWAT officers boarded the plane once it had landed and was moved to a safe location. The flight was deemed safe and able to depart for its destination.

"It was a hoax all the way through," one official involved in the investigation told ABC News.