How do flies fly
Flies are outstanding aerialists flies can hover, move vertically and even fly backwards. Also a tiny fruit fly beats its wings once every 4 milliseconds.
Flies only have two functional wings. The other pair have shrunken into drum-sticks like organs called halteres. Halteres function as gyroscopes that help flies orient themselves in flight.
Mechanical couplings helps flies keep their sense of rhythm. When the front wings go up the halteres go down. Also when the front wings speed up so do the halteres.
Flies' wings flap as opposites, they are not hooked together like most insects. When you watch a fly you can see drum-stick shaped halteres flapping up and down. Flies move at amazingly high speeds, a human equivalent might be patting his head and rubbing his tummy for a mile.
In conclusion flying is a big part of a flies life. It needs four wings to fly, halteres and its real wings.