The air traffic control tower had not been able to make radio contact with the JetBlue flight when they received a false alarm on Tuesday.
CNN  — 

Police surrounded a JetBlue plane at New York’s John F. Kennedy International Airport Tuesday after a false alarm about a hijack incident was sent.

JetBlue Flight 1623 was lined up on the taxiway at the airport waiting to depart when it “experienced a radio equipment problem,” the Federal Aviation Administration said in a statement.

The plane, which was bound to Los Angeles, sent out a hijack code notifying air traffic control that there was a security threat onboard after controllers couldn’t make contact with the pilot, according to a law enforcement source with direct knowledge of the incident.

There is a special code pilots must select using the aircraft’s transponder to indicate such an emergency, the law enforcement source said.

Alexa Curtis, a blogger who was aboard the flight, said she was terrified when she realized something wrong could be happening.

Passengers had been sitting on the plane waiting for the plane to take off when they saw police surrounding the aircraft. Minutes later, SWAT officers boarded the plane, Curtis said.

“SWAT came and told us to pull our phones away and leave (our) hands up,” she said.

Officials inspected the aircraft and determined there was not a security threat, a Port Authority spokesperson said.

Curtis said passengers were not told about the incident and were just taken to a new plane once law enforcement officers were gone.

In a statement, JetBlue said that “while communication was reestablished via alternate channels, authorities responded out of an abundance of caution.”

The FAA and the airline said they are investigating the incident.

CNN’s Rene Marsh, Lauren del Valle and Evan Simko-Bednarski contributed to this report.