A bomber destroyer is a type of fighter aircraft dedicated to destroying enemy bomber aircraft. It is similar in purpose to the interceptor, but differs primarily in form – while interceptors tend to be small, fast-climbing planes, bomber destroyers are typically built on much larger slow-climbing twin-engine designs provided with massive firepower. They also differ from night fighters, although often based on the same airframe, as they lack radar and are intended only for day use.

A number of nations developed such aircraft prior to WWII, all in order to provide an aircraft with enough warload, given the limited engine power of the era, to quickly destroy a bomber. Primary among these pre-war designs were several American aircraft, the Lockheed P-38 Lightning and the Bell P-39 Airacobra being the best examples, both of which were designed explicitly to mount a huge 37mm cannon in their nose for this mission.

Developments in armament, notably the introduction of the 20mm cannon by the RAF, generally led to the disappearance of the bomber destroyer from most air forces. Even small fighters, like the Supermarine Spitfire, were able to carry enough firepower to effectively deal with German and Japanese bombers.

The same was not true for the Luftwaffe however, who were facing much larger bombers than they fielded in return. Whereas German bombers were almost always twin-engined with a few hand-held rifle caliber machine guns for defence, RAF and US bombers were much larger four-engine designs with multiple multi-gun turrets. Since damage resistance is strongly correlated to aircraft size, they found that shooting down the bombers was proving to be very difficult.

Starting in about 1943, the Luftwaffe started fielding an increasing number of bomber destroyers. The most common were modifications of the Messerschmitt Bf 110, night fighters converted to the Zerstörer role by removing the radar and adding more guns. These planes proved to be very effective against US bomber raids in 1943, notably when firing rockets from long range. However they were also rather out of date, the 110 was supposed to have been replaced by 1941, and when the P-51 Mustang appeared the Bf 110 proved to be a deathtrap.

Later designs concentrated on dedicated high-speed planes for this role, notably the Dornier Do 335 Pfeil. Its speed would allow it to remain out of danger from the Mustangs, while still carrying a massive gunload. The Messerschmitt Me 262 also saw widespread use in the destroyer role, where its huge load of four 30mm cannons proved to be more than capable. But in general, few new designs of any sort saw action due to the rapidly deteriorating war conditions.

After the war the destroyer classification disappeared almost instantly. This was due to the introduction of improved high-speed cannons, notably the British Aden and French DEFA. Both of these guns could fire 30mm rounds at rates similar to all four 20mm cannons of the typical WWII aircraft. A single one of these cannon provided any aircraft with enough firepower to be a reasonable destroyer, even light interceptors.

The Soviet MiG-15 may be the last design dedicated to the destroyer role, mounting a 37mm cannon along with two 23mm guns. While this load proved to be less than useful against other fighters over Korea, in the instances where MiG met bomber, massive B-29 Superfortresses in this case, the MiG's caused considerable damage.

The era of the destroyer was finally killed outright with the introduction of the guided missile. Missiles could do considerably more damage than a cannon, at longer range, were lighter, and kept the fighters out of the range of the defensive guns on the bombers. The Germans had experimented with missiles and rockets during the war for all of these reasons, but were unable to field any of their designs.

See also:

interceptor
night fighter