Was it a joke? Or a bungled bid to get an upgrade to first class?

Philippe Jeannard didn't say. He mentioned his past work in advertising, his love of wine, his jaunts several times a year to Palm Beach and his frustration at the lack of French-language books at the Federal Detention Center.

But the 61-year-old French national with the striped-frame eyeglasses and shoulder-length hair left unanswered Wednesday the question that brought him, in cuffs and green prison garb, before a Philadelphia judge.

Why? Why did he don a pilot's uniform and credentials in March and bluff his way into the cockpit of a US Airways plane at Philadelphia International Airport?

In a 90-minute hearing before U.S. District Judge Gene E.K. Pratter, Jeannard pleaded guilty to a single count of fraud. He faces less than six months in prison and is likely to be immediately deported after the judge sentences him, possibly this month. That's also when Jeannard will get another opportunity to talk.

No one was hurt or endangered in the March 20 incident, but it raised concerns about the ease of which Jeannard found himself in the cockpit of the Florida-bound flight.

The hearing did offer a few new details.

Jeannard, who described himself as single and retired, said he travels a few times a year from the home he shares with his mother in France to a condo he rents at the tony Palm Beach Hotel. That was his itinerary in March, with a connection in Philadelphia.

But after landing in Philadelphia and clearing customs, Jeannard arrived at the gate for his Florida flight wearing an Air France shirt with a captain's epaulets and an airline ID card, Assistant U.S. Attorney K.T. Newton told the judge. He had a coach ticket but wanted an upgrade to first class.

Jeannard was told there were no seats and began to argue with the gate attendant, Newton said.

A security guard approached, noticed Jeannard's uniform and asked if he worked for an airline. "Jeannard replied that he did, and then boarded the aircraft," the prosecutor told the judge.

The identification card actually belonged to his mother, a onetime Air France employee.

On board the plane, an attendant escorted Jeannard to the cockpit to speak to the pilots, "a common courtesy" the crew extends to pilots traveling as passengers, Newton said. In the cockpit, Jeannard continued the ruse and said he was a pilot.

When he returned to the flight cabin, Jeannard was furious to learn that there was no room for his bags and that he would have to check them. His outburst led the crew to order him off the plane. Soon after he admitted to officials he was not a pilot or airline employee.

Jeannard, aided at the hearing by an interpreter, said little about the incident but didn't dispute the details laid out by the prosecutor. "It is a fact," he said.

Neither Newton or Jeannard's court-appointed lawyer, federal public defender Elizabeth Toplin, could explain his motives. Toplin said he may have more to say about the incident when he is sentenced.

"I can tell you he never meant to cause any problems," Toplin said.

Jeannard has been held without bail since his arrest - and it hasn't been "fun," he told the judge.

"I'm in jail with a lot of people - it's not really my type of people," he said. "There are killers, drugs."

Pratter said she would try to honor a request from the lawyers for a quick sentencing. (But she also directed them to first determine how a retiree who takes regular jaunts to Palm Beach qualified for a public defender.)

In the meantime, the judge said, she hoped someone could get Jeannard French reading material in jail. And suggested he might have a story of his own to write.

"I would think your experience will make for interesting retelling in the future," Pratter said.