The turret fighter was a concept in air warfare that was quite popular with the British Air Ministry in the 1930s. The theory was that a fighter aircraft could be fitted with a rotating gun turret behind the pilot which would not only provide a defence against an attacking enemy aircraft but could also relieve the pilot from having to get on an opponent’s tail since attacks could be made by the gun turret from nearly any angle (akin to the modern air warfare concept of off-boresight missile firings).
The origins of the concept can be traced back to World War I where the majority of aircraft such as the Bristol F.2B fighter had two man crews with the crewman in the rear position manning a machine gun on a pivot to supplement the fixed forward firing armament available to the pilot. The trend in fighter design in the interwar period leaned towards single pilot aircraft with faster performance and heavier fixed forward armament but there were still those who believed that aircraft armed with trainable weapons would offer an advantage.
The introduction of the powered turret as defensive armament on a bomber aircraft had two distinct impacts on air warfare doctrine. Firstly, it was believed that defensive armament was becoming so potent and the bombers becoming so fast that escort fighters would not be needed. As combat experience would later prove this was a fatally flawed belief. Another impact of powered turrets was the idea of mounting them on fighter aircraft creating a bomber-destroyer that could attack the unescorted enemy bomber formation from any angle with concentrated firepower.
The RAF began a series of experiments using Hawker Demons equipped with a powered turret and it impressed the Air Ministry enough to issue specification F9/35 calling for a two seat, single engined turret fighter armed with four .303 machine guns. This specification resulted in the famous Bolton Paul Defiant turret fighter. At around the same time the Air Ministry issued O30/35 which called for a naval equivalent to operate off the Royal Navy’s carriers. This resulted in the Blackburn Roc turret fighter.
The RAF and Royal Navy leadership and planners might have been confident in the concept but this was in ignorance of how far technology was developing. Single engined fighters were becoming faster and more heavily armed tipping the balance back in their favor over the bombers. This meant that any bomber attack on Britain would require escort fighters and this meant that the Defiant and the Roc would have to ‘mix-it’ with the superlative Messerschmidt Bf109D. The weight of the turret and its mechanism meant that both the Roc and Defiant were sluggish in comparison to the single engined German fighter which was one of the very best in the world in 1939.
When war came the Defiant did prove a nasty surprise to German fighter pilots that attacked from the aircraft’s rear before getting cut to pieces by the .303 guns. It would not last however as German pilots quickly learned that the Defiant could be attacked from below and the front since the aircraft lacked any forward firing armament. Losses mounted dramatically as the German pilots used their superior agility to keep out of the turret gunner’s line of sight. By the time of the Battle of Britain in 1940 it was obvious that the Defiant was going to have to operate with the single engined Hurricanes and Spitfires to keep the Bf109s at bay while the Defiants attacked the bombers. Quietly however the aircraft was slowly withdrawn from frontline service but it was at this point the night bombing campaign began and the aircraft received a new lease of life as a nightfighter carrying one of the first air intercept radar sets.
The Royal Navy’s Roc turret fighter had an even less successful career. Rather than equip entire squadrons with the type it instead served in mixed squadrons comprising Blackburn Skuas (a nearly identical aircraft but lacking the turret and instead used for bombing) with Rocs acting for fighter defence. Very quickly the Roc proved incapable of catching German fighter aircraft and was almost impotent during the Norway campiagn. The aircraft is only credited with a single kill, a Ju88 bomber, in 1940. While useless as a fighter the aircraft did find itself very adept at destroying high speed torpedo carrying E-boats in the English Channel. The aircraft was quickly relegated to second line duties such as target towing and training.
In theory the turret fighter should have been a war winning concept but in practice the aircraft technology in terms of engine and airframe design wasn’t available to compensate for the weight of the turret and even if it was the technology would no doubt be used in single seat fighters as well and the turret fighters would be at a disadvantage again. However the contribution the Defiant made to the development of night fighting tactics can’t be underestimated so as the old saying goes every cloud has a silver lining – and the Defiant could shoot down a German plane inside it thanks to its radar.