Finger-four

The "Finger-four" formation (also known as the "four finger formation"), is a flight formation used by fighter aircraft. It consists of four aircraft, and four of these formations can be combined into a squadron formation.

The formation consists of a flight of four aircraft, composed of a "lead element" and a "second element", each of two aircraft. When viewing the formation from above, the positions of the planes resemble the tips of the four fingers of a human right hand (without the thumb), giving the formation its name.

The lead element is made up of the flight leader at the very front of the formation and one wingman to his rear left. The second element is made up of an additional two planes, the element leader and his wingman. The element leader is to the right and rear of the flight leader, followed by the element wingman to his right and rear.

Both the flight leader and element leader have offensive roles, in that they are the ones to open fire on enemy aircraft while the flight remains intact. Their wingmen have a defensive role — the flight wingman covers the rear of the second element and the element wingman covers the rear of the lead element.

Four of these flights can be assembled to form a squadron formation which consists of two staggered lines of fighters, one in front of the other. Each flight is usually designated by a color (i.e. Red, Blue, Yellow, and Green).

The formation was developed by several air forces independently in the 1930s. The Finnish Air Force adopted it during 1934-1935.Luftwaffe pilots developed the formation independently in 1938 during the Spanish Civil War, and were the first to use it in combat.

In the 1930s the Finnish Air Force, aware of its weakness in numbers compared to its neighbours, sought to offset the disadvantage with a radical re-think of its tactics.

The new tactical philosophy emphasized aggressiveness (a willingness to attack regardless of the odds) and shooting accuracy (at a time when aerobatic skill was prized by most air forces of the time). Hand-in-hand with these changes was the adoption of the pair and four formation, which made for economy and gave the flexibility the new tactics required. The aircraft in the new formations had greater vertical and horizontal separation, so they were free to scan in all directions for enemy aircraft rather than focusing on maintaining a close formation. This allowed the pilots to maintain greater situational awareness and reduce the chance of being spotted by the enemy due to the looser formation. The two pairs could split up at any time and attack on their own. Also, the pilot who spotted the enemy would become the leader of the pair or even the whole flight for the duration of the attack as he had the best situational awareness at that moment in time.

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Wikipedia