Unhappy at being told that he had to check in his carry-on bag, a 41-year-old man on board a Scoot flight said that he had a bomb in the bag.
This led to the Hat Yai-bound plane being forced to turn back to Singapore, and Republic of Singapore Air Force (RSAF) fighter jets being scrambled to escort it.
Yesterday, Hsu Chun Meng was fined $4,500 for breaching the Protection from Harassment Act by using threatening words to cause alarm.
The court heard that Hsu had boarded Flight TR634 from Singapore to Hat Yai, Thailand, with two friends at about 12.55pm on April 5 this year. He tried to put his hand-carry luggage in the overhead compartment but it could not fit.
Flight attendant Boo Joe We, 23, told Hsu he had to check in the bag. He tried to shut the compartment a few more times before giving up.
When Ms Boo asked him if he had any prohibited items in the bag, Hsu, who was unhappy with the way she spoke to him, replied: "Nothing, only bomb."
When the stewardess stared at him, he said: "No bomb lah. Joking. How can it be?"
Ms Boo was initially alarmed by what he said, but then accepted his explanation and went about with the rest of her duties.
When the plane was about to take off at 1.53pm, she told the leader of the cabin crew, Ms Ginny Chiong Wen Chin, 26, about the incident.
Ms Chiong decided to inform the plane's captain, but as the flight was about to take off, she could not enter the cockpit. When the plane was airborne, she entered the cockpit and told the pilot what happened.
After ascertaining the facts, the pilot followed established protocol and reported "Mayday" to the Malaysian air traffic control. He also told Singapore air traffic control that he was heading back to Singapore, the nearest airport.
As the plane carrying 179 people entered Singapore airspace at about 2.20pm, RSAF fighters were scrambled to escort it. The plane landed at a remote area away from the main Changi Airport terminals.
When the police arrived, all the passengers had to disembark while officers conducted a security sweep of the aircraft.
The luggage bags belonging to Hsu and his friends were located and separately removed for security checks.
In all, the flight was delayed for four hours and 48 minutes.
The entire cabin crew and pilots were replaced with a fresh crew, and affected passengers were given vouchers, totalling $13,757.60.
In sentencing, District Judge Adam Nakhoda said Hsu's behaviour could not be tolerated and there was a need to deter like-minded individuals from doing the same.
Last month, a Singapore Airlines flight from Mumbai to Singapore was delayed at the airport in India for more than eight hours, due to a bomb threat. An SIA flight from Taipei to Singapore was delayed by a bomb hoax in February this year. It arrived some 15 minutes later than originally planned.