The Lufbery circle or Lufbery wheel, also spelled Lufberry or Luffberry, is a defensive air combat tactic first used during World War I. While its name derives from the name of Raoul Lufbery, the leading fighter ace of the Lafayette Escadrille, he did not invent the tactic; how it acquired this name is not known, although it may be from his popularization of it among the incoming U.S. pilots he trained. In non-American sources it is in fact usually referred to simply as a "defensive circle". Description This air tactic can only be mounted by formations of aircraft working together: it involves forming a horizontal circle in the air when attacked, in such a way that the armament of each aircraft offers a measure of protection to the others in the circle. It complicates the task of an attacking fighter – the formation as a whole has far fewer "blind spots" than its members, so that it is more difficult to attack an individual aircraft without being exposed to return fire from the others. The tactic, evolved in the context of trench warfare, was not used purely defensively: [The] Lufbery Circle, or follow the leader formation, a great help to each man’s tail. In other words you dive down on a trench, spray it with your guns, and zoom up without worrying much whether a load of nickel jacketed steel is going to crease the seat of your pants. And you don’t worry much because the pilot behind you is taking his turn at spraying the troops in the trench, with the result that they are too occupied with getting out of his way to turn around and blaze away at you as you zoom up. And in the case of the Lufbery Circle, it wouldn’t be healthy for a Hun to try and drop down on the tail of the ship in front of you because you would simply pull up your nose a bit and chew off the soles of his field boots with your bursts. As the state of the art advanced the technique was increasingly used to enable slower, less capable fighters to cope with attacks by an enemy flying superior types, although it has also sometimes been used by light bomber formations. History Perhaps the earliest use of the Lufbery was by formations of F.E.2b aircraft in 1916/17 when in combat with superior German fighters