The flight, which was scheduled to take-off at 0005 hours on Wednesday, is now expected to depart for its destination on Wednesday, an Air India spokesperson said.
"The Mumbai-Singapore flight AI342 with 260 passengers on board was cancelled due to non-availability of commander. The flight will now leave for Singapore at midnight today," the spokesperson said.
Air India has provided hotel and other facilities to the stranded passengers, the airline said, adding that some of the passengers have been booked on other flights.
The airline is facing acute shortage of pilots, particularly commanders, as a good number of them have quit the carrier for better prospects.
Late last month, Air India Mumbai-Riyadh flight was delayed by 20 hours, leading to chaos at the city airport. The airline had then attributed the inordinate delay to flight crew shortage.