It was nearly 10pm on March 26, 1991, when Madam Evelyn Wong received a call informing her that a Singapore Airlines plane - SQ117- had been hijacked.

Now 71, Madam Wong, a retired Senior Staff Sergeant, said: "I thought they were joking and I scolded the guy who called me.

"I said, don't play a fool. How can this be possible?"

When she reached the airport, many officers were already gathered at the police station.

"The spotlights were all on, with the "ang chia" (Hokkien for the red anti-riot vehicle) present," she recalled.

Madam Wong went to the operations room, where she oversaw the receipt and exchange of messages between different police units.

"You got no time to think, the hijackers were saying things like, you better (accede to our) requests or we will shoot a passenger every five minutes.

"I was really nervous, as it was very chaotic and hectic," she said.

The veteran officer, who retired in 1994, cited the incident as one of her most memorable cases.

She took on many roles during her 31-year career with the force, including a stint as personal security officer to the principal of Chung Hwa Girls' High School, now known as Zhonghua Secondary School, from 1965 to 1966.

Chinese students were protesting against the Government then, and had thought the principal was working with the authorities to abolish the Chinese education system. The principal needed a bodyguard as she was at risk of being attacked by the students.

Madam Wong, a trained marksman, was also at the front office of the Paya Lebar Police Station during the 1969 race riots. Those who were injured had turned up at the station to seek help and protection.

The mother of two joined the police force in 1963 after she saw an advertisement. She passed her interview, and trained for nine months at the former Police Academy in Mount Pleasant Road.

Instructors were very strict in those days. "If your buttons were not shiny, you would be scolded.

"When I think back, that was good because it instilled discipline.

"But(back then), I thought it was too harsh. I cried many times during training," she said. "And you would get scolded for crying."

Madam Wong was first posted to Paya Lebar Police Station, and later served in other divisions including the Police Academy and Airport Police.

After retiring in 1994, she joined the Trade Development Board, now known as International Enterprise Singapore, for nine years as an enforcement officer.

She also worked as a Customs officer, and at the Department of Statistics, among others.

Her advice for young officers?

"They must be passionate.

"The force will train you to be a multi-tasker and the exposure you get is really different.

"You won't get this kind of experience elsewhere."