A United Airlines pilot was arrested in a jet’s cockpit minutes before take-off Sunday on suspicion of being drunk.
Hundreds of stunned passengers watched police march the 44-year-old American first officer off the Boeing 777.
The United Airlines flight to San Francisco was delayed at Heathrow for almost three hours while a replacement co-pilot was found.
Cops swooped after a tip-off from ground staff, who suspected the airman was boozing before the 5,300-mile flight.
One stunned passenger said: “We couldn’t believe what we were seeing. The pilot was frog-marched off the aircraft.
“A couple of police officers stormed on to the plane as we were all sitting down and went straight for the cockpit.
“We didn’t have a clue what was happening and we were kept waiting on the plane for hours.
“It is horrifying to think we were apparently so close to being flown thousands of miles by somebody who could have been drinking.
“It was a horrible start to our trip but if it wasn’t for the person who called the cops, our dream holiday could have become a nightmare.”
The pilot was arrested at 9am on board flight 955 after failing a breathalyser.
He was bailed and ordered to return to Heathrow airport police station in January.
The legal limit for pilots is nine micrograms of alcohol in 100 millilitres of breath. The drink-drive limit is 35 micrograms. If convicted, the officer would face up to two years in jail.