Fighter Aircraft

A fighter aircraft is a military aircraft designed primarily for attacking other aircraft, as opposed to a bomber, which is designed to attack ground targets, primarily by dropping bombs. Fighters are comparatively small, fast, and maneuverable. Fighter aircraft are the primary means by which armed forces gain air superiority. At least since World War II, air superiority has been a crucial component of victory in most modern warfare, particularly "conventional" warfare between regular armies(as opposed to guerrilla warfare), and their acquisition and maintenance represent a very substantial proportion of military budgets in militaries that maintain modern fighter forces.

Introduction

The word "fighter" did not become the official British term for a single seat fighter until after the First World War. In the RFC/RAF such aircraft continued to be called "scouts" into the early nineteen twenties. In the French, Italian, German and Portuguese languages the term used (and still in use) literally means "hunter", while in Russian the fighter is called "истребитель" (pronounced "istrebitel") which is literally "exterminator". The U.S. Army labeled their fighters as "pursuit" aircraft until the late nineteen forties.
Fighters were developed in response to the fledgling use of aircraft and dirigibles in World War I for reconnaissance and ground attack roles.
As aerial warfare became increasingly important, so did control of the airspace. By World War II, fighters were predominantly all-metal monoplanes with wing-mounted batteries of cannons or heavy machine guns. By the end of the war, turbojets were already beginning to replace piston engines as the means of propulsion, and missiles to augment or replace guns.
For historical purposes, jet fighters are sometimes classified by generation. The generation terminology was initiated by Russian defense parlance in referring to the F-35 Lightning II as a "fifth-generation" plane.[citation needed]
Modern jet fighters are predominantly powered by one or two turbofan engines, armed primarily with missiles (from as few as two on some lightweight day fighters to as many as eight to ten on air superiority fighters like the Su-37 Flanker or F-15 Eagle), with a cannon as backup armament (typically between 20 and 30mm in calibre), and equipped with a radar as the primary method of target acquisition.

[edit] Piston engine fighters

[edit] World War I

A Sopwith Camel 2F1 biplane at the Imperial War Museum in London
The word “fighter” was first used to describe a two seater aircraft, with sufficient lift to carry a machine gun and its operator as well as the pilot. The first such “fighters” belonged to the “gunbus” series of experimental gun carriers of the British Vickers company which culminated in the Vickers F.B.5 Gunbus of 1914. The main drawback of this type of aircraft was its lack of speed. It was quickly realised that an aircraft intended to destroy its kind in the air needed at least to be fast enough to catch its quarry.
Fortunately another type of military aircraft already existed, which was to form the basis for an effective "fighter" in the modern sense of the word. It was based on the small fast aircraft developed before the war for such air races as the Gordon Bennett and Schneider trophies. The military scout aeroplane was not initially expected to be able to carry serious armament, but to rely on its speed to be able to reach the location it was required to “scout” or reconnoitre and return quickly to report – all the time making a difficult target for AA artillery or enemy gun-carrying aircraft. British “scout” aircraft in this sense included the Sopwith Tabloid and Bristol Scout – French equivalents included the light, fast Morane-Saulnier N.
In practice, after the actual commencement of the war the pilots of small scout aircraft armed themselves with pistols, carbines and an assortment of improvised weapons with which to attack enemy aircraft – proving to be as successful in their efforts as specifically designed “fighter” aircraft.
It was inevitable that sooner or later means of effectively arming “scouts” would be devised. One method was to build a “pusher” scout such as the Airco DH.2, with the propeller behind the pilot. The main drawback was that the high drag of a pusher type's tail structure meant that it was bound to be slower than an otherwise similar tractor aircraft. The other was to mount the machine gun armament outside the arc of the propeller. Given the tendency of early machine guns to jam (and hence the need for the pilot to have access to the gun’s breech) as well as determining the aiming point, this was a stopgap solution at best. Despite this mounting a machine gun to fire over the propeller arc was to remain in service from 1915 on the Nieuport 11 until 1918 on the Royal Aircraft Factory S.E.5 with its purpose built Foster mounting.
So clear was the need to arm a tractor scout with a forward firing gun whose bullets actually passed through the propeller arc that inventors were busy trying various methods in both France and Germany. Hanz Schneider had patented a device before the war to interrupt the machine gun's stream of bullets (by preventing it from firing when the propellor's blade was in the way) before the war and Anthony Fokker developed this into the Interrupter gear that would make the Fokker Eindecker such a feared name over the Western Front despite it being an adaptation of an obsolete pre-war French Morane-Saulnier racing monoplane. Simultaneously, Roland Garros (the first French 'Flying ace') was also working on a Interrupter gear, which attempted to time the firing of the individual rounds similarly when the propellor wasn't in the way. Unfortunately his choice of machine gun was poor - the gas operated Hotchkiss wasn't predictable enough to be able to time the firing and as a desperation measure he fitted metal wedges to protect the propellor's blades. At the same time the RNAS was taping up the blades on its scouts so that any rounds that damaged the prop wouldn't cause it to fail before the aircraft could be landed, with the fabric from the tape hopefully holding the blade together.
The success of the Eindecker started a cycle of improvement among the combatants, building ever more efficient single seat fighters. The Albatros D.I of late 1916 set the classic pattern followed by almost all such aircraft for about twenty years. Like the D.I, they were biplanes (only very occasionally monoplanes, or triplanes). The strong box structure of the biplane wing allowed for a rigid wing that afforded accurate lateral control, essential for fighter-type maneuvers. They had a single crew member, who flew the aircraft and also operated its armament. They were armed with two synchronised Maxim-type machine guns, which were much easier to synchronise than other types – firing through the propeller arc. The gun breeches were typically right in front of the pilot’s face. This had obvious implications in case of accidents, but enabled jams (to which Maxim-type machine guns always remained liable) to be cleared in flight and made aiming them much easier.