Katsutoshi Jitsukawa, Japan Airlines first officer, was arrested at Heathrow Airport, London, for being under the influence of alcohol.
He was detected by the sensitive nose of a crew bus driver, who smelled alcohol and reported him to police, according to Japanese broadcaster NHK.
London's Metropolitan Police said tests revealed he had 189 mg of alcohol per 100 ml of blood in his system - nearly ten times the 20 mg limit for a pilot.
Jitsukawa said he had drunk about two bottles of wine and a pitcher of beer the previous night, NHK said.
He was arrested on October 28 just 50 minutes before the plane was due to leave, with the flight finally taking off after a 69-minute delay.
Japan's Transport Ministry on Thursday issued a document directing all Japanese airlines to report by month-end measures being taken to control drinking by flight staff.
Singapore Airlines also hit the news after one of its pilots failed a blood alcohol test in Melbourne and prompted the cancellation of two flights.
He was found to have 189mg of alcohol per 100ml of blood in his system - the legal limit for a pilot is 20mg. He is being held in custody and will be sentenced on November 29.
"We are certain (the in-house breath test) wasn't conducted properly", JAL communications chief Muneaki Kitahara told reporters Thursday.
Airlines have their own regulations, with JAL saying its rules banned pilots from drinking 12 hours before flying - a limit they now said would be pushed back to 24 hours.
"The company sincerely apologizes to the passengers and to all affected by the employee's actions", JAL said in a press release.
The incident came to light after All Nippon Airways Co. on Wednesday apologized for five flight delays in Okinawa last week because a pilot was not in a fit state to work following a night of drinking. Before boarding the bus, the copilot and the two captains took a company-administered breath test at JAL's Heathrow office.