Last week (September 10) we told you the story of a Dornier 17 that was discovered at the bottom of the English Channel 70 years after being shot down by a Boulton Paul Defiant “turret fighter” in August 1940. As it turns out for the Defiants, that engagement would essentially mark their end as a frontline fighter in the Battle of Britain. The 290-mph Defiant was obsolete and vulnerable almost before it was deployed in May 1940. The aircraft was designed to attack unescorted bombers by flying in large formations while the “turret gunners” used a dorsal mounted turret to fire at incoming bombers with four 7.7-mm Browning machine guns.
At first the Defiants were able to devastate German bomber formations, but soon the Luftwaffe figured out they had no forward-facing armament and attacked them from below, where the turrets could not shoot. The Defiants started to suffer heavy losses. After a four-day engagement August 24-28, 1940, in which nine aircraft were lost, they were redeployed and proved better effectiveness as night fighters, electronic counter-measure aircraft (ECM), and aerial gunnery trainers.
See the article below from Xplanes about the history of the Defiant:
On July 19th 1940, nine Boulton Paul Defiant “turret fighters” of 141 Squadron - on their first operational sortie in the south of Britain - encountered a force of at least twenty Messerschmitt Bf 109s fighters whilst on patrol in the English Channel. Seven aircraft were shot down almost immediately - the remaining aircraft being saved by the intervention of a squadron of Hawker Hurricanes . Ten aircrew were lost. the squadron was withdrawn from the Battle two days later.
Between August 24th and 28th, the Royal Air Force’s other Defiant unit - 264 Squadron - lost at least nine aircraft and eleven aircrew, and was also withdrawn.
The Defiant was a creation of an earlier age. Up to the mid 1930s, multi-engined bomber aircraft were faster than the bi-plane fighters. The idea of bombers being escorted by fighters to their destination was not given serious thought, especially considering range limitations. “The bomber will always get through”
sums up a lot of theorist’s views of the time.
The “turret fighter” was conceived to help defend Great Britain against large formations of incoming unescorted enemy bombers. Working in groups, the gunners would co-ordinate their fire at the enemy formations - the weaponry being more powerful and longer lasting than what a standard fighter was capable of carrying.
It’s combat debut over Holland and Dunkirk, in May 1940, was chaotic to say the least. 264 Squadron
suffered losses at the hands of the Messerschmitt Bf 109 fighter - an aircraft it was not designed to fight against, but also claimed large numbers of kills. This is partly down to suprise - a Defiant was defenseless if approached from the front or underneath, but formidable if mistaken for another aircraft and approached from above and behind - and also down to the general phenomenon of “overclaiming” during the confusion of aerial combat. 264 Squadron developed a “defensive circle”
tactic to help against attacks by German fighters, but the Defiant was very much out of its depth in their presence.
In the Battle of Britain, there were to be no moments of glory. The Defiants of 141 Squadron adopted no defensive tactics and were shot down flying in small, straight and level formations. 264 Squadron, based in and during the heart of the Battle, fought bravely but were overwhelmed in the chaos. Aerial combat theory had changed - the fighter, not the bomber, had arguably become the key to victory.
The two squadrons eventually regained strength and became night fighter units. In this role, the Defiant was much more successful.