A British Airways jumbo jet flying to New York turned back after the US objected to one of its passengers.
The BA jet was carrying 239 passengers when it turned back
Three hours after take-off on Wednesday the Boeing 747, with 239 passengers, turned around after a US request that the man should not be allowed to land.
They said his name matched one on a terrorism watch list. He was met by British police on landing and was questioned, but later released.
BA said there was "no threat to the safety of the aircraft".
BA flight 175 landed back at Heathrow at 1730 GMT - more than six hours after take-off.
A spokeswoman said BA took the decision to return to Heathrow Airport, west London.
She added: "The remaining passengers will depart for JFK [airport] at 2000 GMT this evening."
A spokeswoman from the US Transportation Security Administration said: "There was a person travelling on a French passport who was a positive match with an anti-terrorism watch list.
"Homeland security made the match by checking data transmitted after the flight departed from London."
In September, Yusuf Islam, the British singer formerly known as Cat Stevens, was shocked when his plane to Washington was diverted on national security grounds.
He believes a spelling error by the FBI was the reason he ended up on a "no fly" list and asked his lawyers to look into it.
US Secretary of State Colin Powell said his case would be reviewed.