IT was costly threat for former Aetos security officer who threatened to kill his colleague should he lose his job.

Faisal Abdullah, 39, was fined $2,000 on Thursday after admitting to threatening Ms Sharifah Shahirah Syed Sulaiman Aljunied at Changi Airport's Terminal 2 on Nov 13 last year.

He warned her that he would kill her if he was fired from his job. He said he knew where she lived.

A district court heard that Faisal and the 21-year-old security screening officer were on duty that day at a gate holding room when Ms Sharifah told him to push a baggage on a X-ray machine roller. She was then performing hand-held metal detector screening.

After the flight duty, Faisal approached her over the earlier incident and they had an argument. He then uttered the threat with intent to cause alarm to her.

A second charge of punching her on the left chin was taken into consideration.

He told the court he did not have any ill intention when he made the threat. A sole breadwinner, he said he was dismissed from his job after the incident.

District Judge Hamidah Ibrahim imposed a fine, given that this was his first offence.