Worst British twins, and how to fix?

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Botha would have been at least adequate with a pair of R1820s
It would have solved the power problem, it would not have solved the poor/restricted vision and the control issues (might have made them worse?), the high landing speed. Other problems that might have been fixable were petrol and exhaust fumes entering the cockpit and that asymmetrical dorsal turret causing rudder buffet.

This one was not really Blackburn's fault. That was the turret they were given and it caused a lot of problems on other aircraft.
The high landing speed may have been fixed with more/better training but the British didn't have a good twin engine trainer for "high" performance twins.
I Know that Botha and "High" performance seem like a contradiction but while the Anson gave a lot pilots a gentle introduction to twin engine flying even a lightly loaded Botha had about 50% increase in wing loading and a landing speed in the low 80s. Anson had a higher landing speed than a Blenheim I so the Botha was bit of a handful in 1940 with no redeeming features.
 
The question that always comes to my mind is, if the Botha was not around what what would be taken away to do the high speed twin advanced trainer role?
Blenheim.
Bothas in trainer role are red herring, used to defend the good-awful design. And slow, as very slow.
 
The question that always comes to my mind is, if the Botha was not around what what would be taken away to do the high speed twin advanced trainer role?
They were used for a wide variety of training. Navigators, bomb aimers and gunners come to mind.

In April 1942 No 3 Air Gunnery School opened at RAF Castle Kennedy in SW Scotland. Its initial equipment was 46 Bothas with 27 Battle target tugs. Other training schools in that area had been using Bothas since 1940.
 
Blenheim.
Bothas in trainer role are red herring, used to defend the good-awful design. And slow, as very slow.
A Blenheim didn't have the internal space for navigator / bomb aimer training. Larger aircraft capable of carrying an instructor and multiple pupils was what was needed. Another type used early War was the early Whitleys. Later of course trainer versions of the Wellington came to be used as Bomber Command moved to 4 engined heavies.
 
Would that not reduce the number of Blenheims for operational tasks? Whatever one thinks of the Blenheim it was the period light bomber of the RAF.

We want the pilots and other crewmembers to train in a safe aircraft.
Blenheims were ill suited for daylight tasks against the German opposition, and used 4-8 times as much of pilots per ton of bombs delivered than the better bombers RAF had in service.
 
Training accidents were much more common in the WW II era (and into the 50s) than they are now. But the Botha was among the front rank of most dangerous. One source (welcome to correction) claims out 478 aircraft in the training units 169 were written off in accidents, including 24 ditched into the sea after engine failures. Better engines could help with this, both through fewer engine failures (same engine as the Skua/Roc) and the fact that the Botha struggled and often failed to fly on one engine. British seemed to have problem with this. Other countries were not immune or the short periods of time (France ?) didn't really register.
The courage of the crews that under took long over water flights with such machines (Whitley's with large radar arrays) is often overlooked.
It took a while for the idea that twin engines alone were NOT enough to sink in. You needed both enough power to fly on one engine and a good enough propeller to fly at a useable speed. Using the smallest, cheapest engines was not, in the end, a smart choice.

The Lockheed Hudson, a converted airliner, was a much better choice for ASW and maritime recon because most of them would continue to fly on one engine and not slowly and steadily descend to water/ground. Hudson also had plenty of room for students. It cost more though.

Getting back to the original post.

Blackburn Botha
Armstrong Whitworth Albemarle
Saro Lerwick
Blackburn B-20

The first 3 were under powered. Then we can get into the other problems.
The Blackburn doesn't have enough track record. It crashed after about 13 days so high speed testing is doubtful. Maybe the Vulture wasn't the best choice of engine but the crash was due to alerion flutter. Not the first or last airplane to have that problem, but then there is the problem of if it was actually useable as a service aircraft.

A lot may depend on the sea state requirement for landing and take-off. It may have worked well in sheltered waters but if they wanted it to land and take-off in 6 ft waves it might not have worked? or needed a lot of work on the shape of the nose float/pontoon and wing floats.
 
And with a design like that you dare mock French ones ?
 
Spec R.1/36 saw 4 submissions from Blackburn, Shorts, Supermarine & Saunders-Roe. The last named "won" with the S.36 Lerwick design, gaining a small production contract as a result. A single Blackburn B.20 was ordered but was only ever meant to be a "proof of concept" aircraft.

The Spec called for an aircraft that was "highly seaworthy and of sufficiently robust construction to ride out rough seas at moorings and to operate in rough water conditions from so-called sheltered waters". So no intention to operate any of the designs on the open sea in 6ft waves.

This is another example of the difference between USN and British practice in the maritime aviation sphere. The RAF flying boat bases were generally in sheltered locations adjacent to land masses and the RN made little use of seaplane carriers interwar, and when they did the RAF aircraft supplied were no larger than the Walrus. This is unlike the USN where it used a significant number of AV/AVP/AVD from the 1930s, starting with converted 4 stack destroyers and minesweepers to support their flying boats often in much more open waters.

Until the mid-1930s most flying boats were biplanes with somewhere high up to mount the engines and props away from any sea spray. The move to monoplanes generally meant accepting a deep and therefore draggy fuselage to achieve the same effect e.g. the Sunderland (Consolidated got round the problem with the PBY parasol wing layout).

Blackburn's novel solution got around the problem with the split hull. The B.20 had about 75% of the air drag of a conventional deep hull. And on the water the engines and props were kept well clear of spray. An added benefit was that the top of the float provided space for the crew to do all the water handling, mooring etc, and when the fuselage was lowered hangar storage became easier.

The split hull concept didn't die with the crash of the B.20 13 days after its first flight. Blackburn proposed its B.40 design to Spec R.13/40 using the same concept. Span 98ft, weight 52,000lb powered by 2x2,080hp Bristol Centaurus radials, armament 1x20mm plus 4x0.5" & 4x0.303" plus bombs. Sir Henry Tizard described it in late 1940/early 1941 as "An experimental machine not of any great importance from the point of view of the war unless the war goes on a long while". But he still thought the experiment was worth pursuing. The project continued until cancelled in Jan 1942. Problems were its predicted range was inadequate as well as its single engined performance.

Blackburn also pursued the concept in the B.44 single seat floatplane fighter to Spec N.2/42. Again for operation from sheltered waters. Span 50ft, weight 14,000lb, 2,240hp Napier Sabre IV giving 360mph at 25,000ft toting 4x20mm & 2x500lb bombs. It only reached the mock up stage before being cancelled as a result of work done on the design at RAE Farnborough which indicated it would have handling problems on take off, and might not be able to rake off at all!!
 

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