SAN FRANCE-ISCO?

Airline sent her on wrong flight 8,500 mi. away,

United Airlines workers took stupidity to new heights when they allowed a woman bound for France to board the wrong plane — and fly thousands of miles in the opposite direction.

The epic flub left traveler Lucie Bahetoukilae (above) stranded in San Francisco — instead of Paris — for 11 hours before she was finally able to head another 5,500 miles back east to get to her destination.

Bahetoukilae, of France, said she accidentally took her boarding pass, marked “Newark to Charles de Gaulle,” to the incorrect gate on April 24, where a United rep scanned it.

But instead of sending her to the right gate, the worker allowed her to board the California-bound plane.

“When she went to sit, someone was sitting there already,” her niece, Diane Miantsoko, told WABC-TV.

Stunningly, a flight attendant looked at her boarding pass — which clearly read “seat 22C bound for Paris” — and still sat her somewhere else on the wrong plane, the weary traveler said.

Bahetoukilae, who doesn’t speak English, said the confusion happened when United made a lastminute gate change without announcing it in French or notifying her by e-mail.

“If they would have made the announcement in French, she would have moved gates,” Miantsoko said.

Instead of a 7 ½-hour flight to the City of Lights, Bahetoukilae trekked all the way to the City by the Bay, where she suffered through the grueling layover before she was rerouted.

She traveled a total of 28 hours before finally arriving in Paris — but despite the infuriating hassle, her family was more worried about the airline’s apparent security lapse.

“This is not about money,” Bahetoukilae’s niece told WABC. “This is about United getting serious with their employees . . . With everything going on this country, people have to be more careful.

“They didn’t pay attention. My aunt could have been anyone. She could have been a terrorist and killed people on that flight, and they didn’t know they didn’t catch it.”

United has apologized.

“We deeply apologize to Ms. Bahetoukilae for this unacceptable experience,” the airline told The Post in a statement.

“When she arrived in San Francisco, we ensured she got on the next flight to Paris and refunded her ticket. Our customer care team has reached out to her directly to ensure we make this right. We are also working with our team in Newark to prevent this from happening again.”

Bahetoukilae got a refund for the airfare, hotel accommodation in San Francisco and a voucher for another trip, WABC reported.

United has made headlines for several recent fiascoes, including the violent ejection of Dr. David Dao from a flight on April 9 to make room for crew members.