The flight was scheduled to depart for Singapore at 9:05 a.m., but the aircraft had to return to the gate after it had begun taxiing toward the runway, according to The Straits Times.
The safety of our customers and crew is always our top priority, the airline said in a statement, adding that the pilot required medical attention.
The flight eventually departed for Changi Airport at 3:40 p.m. and landed in Singapore at 7:36 p.m.
Singapore Airlines said all affected passengers were provided with meal vouchers, refreshments, and drinks during the delay.
The national carrier was voted the most loved international airline by readers of Travel + Leisure magazine at the World’s Best Awards in July last year, praised for its "excellent in-flight service and cabin comfort."
Singapore Airlines has long upheld a strong reputation for excellence in safety, service, and customer experience.