Prototype of the Blackburn Botha
|
|
The Blackburn Botha was one of the least successful British aircraft of the Second World War, suffering from a serious lack of engine power, and with a front line career of only three months.
The Botha was designed to satisfy Air Ministry specification M.15/35, for a three man land-based twin engined torpedo bomber/ reconnaissance aircraft. Two aircraft were designed to match this specification – the Blackburn Botha and the Bristol Beaufort. Both aircraft were designed around the 850hp Bristol Perseus sleeve-valve radial engine, which proved enough power for the original three man aircraft, but in 1936 the Air Ministry decided to add a fourth crew member. This increased the weight of both aircraft to such an extent that the Perseus engine was no longer seen as adequate. More powerful Bristol Taurus engines were available, but only in small numbers. The Beaufort was given the more powerful engine, and had a successful (if brief) front line career, before becoming the basis of the Bristol Beaufighter.
No Taurus engines were available for the Botha, and so Blackburn was forced to work around the Perseus. Despite this a contract for 442 aircraft was placed in December 1936, and the first Botha made its maiden flight on 28 December 1938.
The Botha was a high-wing monoplane. The pilot’s cockpit was positioned well forward, giving the pilot a good view down and ahead of the aircraft. The navigator and radio operator positions were behind the pilot’s cockpit, and the navigator also doubled as the bomb aimer, with a bomb aiming position in the nose. Defensive firepower was proved by a rather odd looking egg-shaped gun turret behind the wings. The first few Bothas were powered by the 880hp Perseus X, but most were given the 930hp Perseus XA. Even so, they were still underpowered, and as a result were slower, and had a worse rate of climb, than when first designed.
The Botha began to reach training units in significant numbers early in 1940. Four aircraft were lost in fatal accidents between 5 March and 8 July 1940, and the Botha never shook the evil reputation it gained in this period.
The lack of power meant that the Botha was outperformed by the Bristol Beaufort in just about every way – the Beaufort was faster, with a better rate of climb, a longer range and better endurance. The higher service ceiling of the Botha was of little relevance in a torpedo bomber.
The Botha only equipped one front line unit, No.608 (North Riding) Squadron of Coastal Command. This squadron received its first Bothas in July 1940, and flew its first operational sortie on 10 August 1940. Despite the poor reputation of the Botha, only one of the thirty aircraft operated by No.608 Squadron was lost during the Botha’s three months of front line patrols over the North Sea. The last of those sorties came on 6 November 1940, and from then until March 1941 the squadron reverted to the Avro Anson. No.608 Squadron needed a reliable aircraft that was easy to fly on long coastal patrols, and the underpowered Botha was not that aircraft.
The Botha went on to be used by twenty training units, nine schools of technical training and the Target Towing Unit at Abbotsinch. Even here the Botha had a short lifespan – all the nine training units to receive the Botha in 1941 had replaced it by the end of 1942 (all but two by July 1942), and off the eight training units to receive the Botha during 1942, all but No.11 Radio School at Hooton Park had replaced their aircraft by the end of 1943. The Botha retained a poor reputation, but its record with the training units was perfectly acceptable.
One of the units to use it for longest was No.3 School of General Reconnaissance, which operated it for just over two years, from November 1940 to December 1942. From March-December 1942 this unit’s Bothas logged over 16,000 hours, and only six aircraft were lost. Of these one was lost in an aerial collision, and another when it was hit by another aircraft while at dispersal. The main early cause of losses was damage from sand caused by a lack of air filters on the Perseus engines. The majority of surviving Bothas were declared obsolete in August 1943, and were quickly scrapped.
Engine: 2 x Bristol Perseus XA
Power: 930hp each
Crew: 4
Wing span: 59ft 0in
Length: 51ft 0.5in
Height: 14ft 7.5in
Empty Weight: 12,036lb
Full Weight: 18,450lb
Maximum Speed: 249mph
Service ceiling: 18,400ft
Maximum Range: 1,270 miles
Armament: One 0.303in machine gun in nose and two in dorsal turret
Bomb load: 2,000lb – either bombs or internally carried torpedo.
