An American Airlines flight from London to Los Angeles doubled back Wednesday after two passengers and "some" crew members fell ill, according to an airline spokesperson.
American Airlines flight 109 departed Heathrow shortly after midnight local time and returned to the airport around 5 p.m. after a "medical emergency" occurred on board, the airline said.
"Two passengers and some of our flight attendants complained of lightheadedness during the flight," an airline spokesperson said in an email Thursday.
The airline did not specify how many crew members were affected, but The Telegraph in Britain reports five flight attendants felt sick and one collapsed. American Airlines could not confirm a flight attendant fainted.
According to The Telegraph, the crew asked passengers if a doctor was on board.
The captain decided to land in London, and paramedics evaluated the passengers and crew. No one needed further medical attention.
A maintenance team inspected the Boeing 777 and conducted a test flight, according to the airline, which said no issues with the plane were identified.
"Out of an abundance of caution, all of the air filters on the aircraft were replaced," the airline said.
American Airlines apologized to passengers Wednesday.
Ari Mason contributed to this report.