All Nippon Airways Co. apologized Wednesday for flight delays in Okinawa last week because a pilot became unwell after a night of drinking alcohol.

Five domestic flights departing and arriving in Japan's southern island prefecture were delayed for up to 58 minutes while a replacement pilot was found.

The pilot in his 40s had been drinking until 10 p.m. on the night of Oct. 24 in Ishigaki city in Okinawa and called in sick the next morning, being unable to make his first flight at 8:10 a.m., said the company.

In its apology, ANA said it will ensure its staff are properly educated about alcohol in order to prevent similar situations in the future.