Military fly over

Every Saturday just after 7 pm I get startled by a military jet flying very low and very fast over my apartment. I have looked all over the internet to find information as to why this happens but haven't found any. I live very close to the Prime Minister's palace so am guessing that it is a military tradition for them to do this each week.

I actually live just down the street from the first Prime Minister of Singapore, Mr. Lee Kuan Yew. He held the office from 1959 to 1990. Interestingly, his eldest son is the current Prime Minister and lives at the official palace. Lee Kuan Yew lives on Oxley Road (I live on the corner of Oxley Road and Eber Road) and has 24 hour armed guards outside his house. They actually block off the street from about 10 pm to sometime early in the morning to prevent noise in front of his house. It is just a normal house on a city street and without the gates and the armed guards you'd never know somebody important lived there.