He appeared in court in London on Thursday and pleaded guilty to exceeding the alcohol limit, according to the BBC.
A Japan Airlines pilot was arrested for being 10 times over the legal alcohol limit less than an hour before he was supposed to take off.
The flight to Tokyo took off after a 69-minute delay with Jitsukawa not aboard.
A spokesman for the London police said a test on the co-pilot taken 50 minutes before the flight's scheduled departure revealed 189 milligrams of alcohol per 100 millilitres of blood in his system - nearly 10 times the 20-milligram limit for a pilot.
He had reportedly consumed two bottles of wine and more than 1.8 litres of beer over six hours on the night before the flight.
JAL said the co-pilot was arrested Sunday for violating British aviation law.
He will be detained until his sentence on November 29.More news: Racist robocall targets Stacey Abrams, Oprah in Georgia governor’s race
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Japan's Transport Ministry also responded to the incident, promising to institute a national standard for pilot blood-alcohol levels.
The almost 12-hour flight from London to Tokyo normally has two captains and a co-pilot.
The airline issued an apology, promising "immediate actions to prevent any future occurrence".
In May, a Japan Airlines flight attendant was caught drinking a beer in a bathroom during a flight, Kyodo reported.
"We will use all possible means to ensure flight safety", the minister, Keiichi Ishii, told reporters Friday.
Other incidents of drunkenness among crew members have drawn scrutiny to the industry. The limit for pilots in the United Kingdom is 20 milligrams.
Passengers had already started to board the plane before he was escorted from the cockpit in handcuffs.