PHILADELPHIA — If there’s any upshot to a misunderstanding that grounded a small aircraft in Philadelphia — and most likely scared the wits out of two Jewish teenagers — it’s that the general public might now know a bit more about tefillin.

A 17-year-old Orthodox Jew donned his prayer phylacteries to recite morning prayers during a flight last Thursday morning from New York’s LaGuardia Airport bound for Louisville, Ky., according to an FBI agent.

Unfamiliar with the prayer boxes — and fearful that it could be a wired bomb — the captain decided to notify federal authorities of a disruptive passenger and land the plane in Philadelphia, according to FBI Special Agent J.J. Klaver, a local field officer who swung into action as the spokesman on the ground.

Within minutes, headlines on local and national news sites reported the “tefillin” incident as reporters scrambled to find out exactly what they might be.

The plane landed in Philadelphia at about 8:50 a.m. and was searched by the TSA and Philadelphia Police Department. The boy and his 16-year-old sister were interviewed by FBI agents, though they were never actually in custody, according to Klaver. Authorities did not disclose the passengers’ names.

Klaver stressed that the incident was a misunderstanding and that the passenger had done nothing illegal.

“There is no restriction against religious practices on the aircraft as long as you are not interfering with the flight crew,” he said.

The plane was operated by Chautauqua Airlines, an affiliate of U.S. Airways. The flight had a total of 15 passengers.

According to a statement by Republic Airlines, which owns Chautauqua Airlines, “When our crew tried to discuss the issue with the passenger, they did not receive a clear response.”

The airlines said that “while we always regret any inconvenience to our passengers, safety and security must remain our top priority. In this case, making an unplanned stop in Philadelphia was determined to be in the best interest of our customers and our crew.”

Rabbi Solomon Isaacson of Congregation Beth Solomon Kollel and Community Center in Northeast Philadelphia said he understood how there could have been initial confusion, but couldn’t fathom why the matter took at least two hours to clear up.

“With what’s been going on lately, I can understand how people would be scared of something they don’t know. Obviously, they had no idea what this was. They saw a guy with a black box and they are thinking that he could be an individual who is willing to sacrifice his life,” said Isaacson.

Once it was clear that they weren’t dealing with a terrorist, he said, “that should have been the beginning of the end of it.”

Rabbi Jay Stein, president of the Vaad: The Board of Rabbis of Greater Philadelphia, also offered a somewhat mixed reaction.

Stein of Har Zion Temple noted that it’s a sad commentary on the state of the world that people have become so paranoid. He also said the misunderstanding shows how little Americans know about the religious practices of other faiths. On the other hand, Stein said that fear of the unknown is certainly understandable.

“People are living in a crazy world where people are doing crazy things,” the rabbi said. “If you see somebody doing something that is out of the ordinary, of course you are going to be concerned. I would always prefer people to be more cautious than less cautious.”