A Long Island woman is suing United Airlines for $5 million, saying she was dragged off a flight and jailed for three days after a heated argument over where she sat on a flight to Alaska.

Jean Mamakos, 68, of Huntington, tried to switch to an empty exit-row seat during a layover in Seattle during a March 2013 flight but returned to her own seat when told she’d have to pay an additional $109, her Brooklyn federal-court suit states.

Mamakos’ attorney, Patricia Swicicki, said her client was then violently removed from the flight.

United reps did not immediately respond to a request for comment on the case.