The US Federal Aviation Administration (FAA) prohibits airline pilots from drinking alcohol within eight hours of getting into the cockpit, but United Airlines is implementing even stricter rules after a recent incident where pilots allegedly showed up intoxicated for a flight.

USA Today reports that the airline issued a directive to pilots compelling them to have their last drink no less than 12 hours before flying.

The FAA also bars pilots from having a blood-alcohol content higher than .04 per cent when reporting for duty.

“It is essential that pilots understand that minimal compliance of United’s policy does not assure compliance with DOT (US Department of Transportation) or individual state standards,” said the carrier.

“Countries outside the United States have differing policies which include a blood alcohol content of 0.00% and punishment criteria. It is the sole personal responsibility of the pilot to report for duty as defined by the company, DOT/FAA or the governing country.”

The policy change comes in the wake of the recent arrest of two United Airlines pilots at Glasgow Airport in Scotland on suspicion of intoxication.

The arrests caused the Saturday morning flight to Newark International Airport to be cancelled.