Kenneth Smith, 26, of Philadelphia, entered the plea to the charges of malicious false information about an explosive.
Smith entered the plea in the hopes of avoiding jail time. But, in court, he risked going to jail after all when he admitted using drugs.
During questioning, he admitted to smoking pot a couple of days ago. The judge said the bomb threat was "worse than dumb," and using drugs while out on bail is "super dumb."
Smith had no comment on his way into court, except to say he was sorry.
Smith remains free on bail and promised the judge he would remain drug free until his sentencing, which is scheduled for April.
On September 6th, Smith called the airport with a bomb threat, implicating his girlfriend's ex-boyfriend.
That boyfriend, Christopher Shell, was on a plane headed to Texas for his birthday. The plane was forced to turn around and Shell was taken into custody.
But, as investigators soon learned, it was all a hoax.
Investigators earlier said Smith called in the fake threat because he allegedly wanted to "avenge" his girlfriend, Shell's ex, because Shell had allegedly posted a compromising picture of her on Facebook.
"You know, love makes you do some crazy things," Smith said.
Smith faces a maximum possible sentence of 15 years in prison, a fine of up to $500,000, special assessments, supervised release and restitution for the costs associated with the crimes.
He has also agreed to write a letter of apology to every passenger on board the flight, to reimburse the costs of emergency response, and to pay restitution to his victims, the U.S. Attorney said.