SINGAPORE - A man who unlawfully operated a drone in September 2020, causing two Republic of Singapore Air Force (RSAF) aircraft to be rerouted, was fined $51,000 on Thursday (April 14).

The incident caused a risk of collision and the RSAF also had to impose a 30-minute runway closure.

The Straits Times understands that this is the largest fine imposed for a case involving the unlawful flying of drones.

Deputy Public Prosecutor Chong Ee Hsiun had said that Jason Ng Yok Sen's offence is the first one that led to both diversion of aircraft and closure of runway.

Before handing down the sentence on Thursday, District Judge Lorraine Ho also noted that Ng's act had led to a disruption of military operations.

Ng, 43, pleaded guilty on Tuesday to three charges linked to the drone - an unmanned aircraft (UA) - under the Air Navigation Act. Fourteen other charges were considered during sentencing.

He will have to spend 100 days behind bars if he is unable to pay the fine.

Ng bought the DJI Mavic 2 Zoom drone, which weighed about 900g, in late 2018.

He registered the device with the Civil Aviation Authority of Singapore on Jan 11, 2020.

Before operating the UA outdoors for a recreational purpose at an altitude exceeding 60m above mean sea level, Ng had to obtain a Class 2 Activity Permit. The court heard that he did not do so.

He went to Taman Jurong Park on two separate occasions in May 2020 and flew the drone until it reached heights of over 100m.

Ng was at the park at around 7.40pm on Sept 8 that year when he again launched the drone, and it reached an altitude of 134m above mean sea level.

He operated the device for about 20 minutes and it covered a distance of 931m in the vicinity of Corporation Road.

The court heard that his actions that evening endangered RSAF personnel and aircraft.

In an earlier court proceeding, DPP Chong said: "The altitude and location of the accused's UA meant it was directly within the flight path of a Tengah Air Base runway. Two RSAF aircraft with a total aircrew of four personnel were scheduled to use that runway for landing within the next hour after the drone was detected by the airbase aeroscope.

"There was a risk of collision, which would have threatened both lives and property. The RSAF had to reroute the two affected aircraft away from said runway, and impose a 30-minute runway closure due to the accused's actions."

Defence lawyer Azri Imran Tan from IRB Law had pleaded for his client to be given a fine of up to $46,000, saying: "It cannot be ignored that there was no actual injury to persons and/or damage to property or aircraft."

The lawyer also said that Ng was "a mere drone hobbyist" who had "no specific aims or malicious intentions of endangering lives or property".