我们来看看dogfight的定义

http://en.wikipedia.org/wiki/Dogfight

A dogfight or dog fight is a common term used to describe close-range aerial combat between military aircraft. The term originated during World War I, and probably derives from the preferred fighter tactic of positioning one's aircraft behind the enemy aircraft.

From this position, a pilot could fire his guns on the enemy without having to lead the target, and the enemy aircraft could not effectively fire back. (清注意这句话)

The term came into existence because when two fighter aircraft circle each other trying to achieve this position, it resembles two dogs chasing each other's tails.

还“Aircrafts not horse, there is no head to tail chase.”呢。呵呵。