Worst British twins, and how to fix?

[Admiral Beez]

The British had some twin engined, ICE-powered aircraft that were duds, such as the Avro Manchester. I would include in these the following:

Blackburn Botha
Armstrong Whitworth Albemarle
Saro Lerwick
Blackburn B-20

With effort the twin-engined Manchester was made into the superlative four-engined Lancaster. What can we do to get other British ICE-powered twin-engined duds into successful territory?

 

[Howard Gibson]

The Manchester had a good airframe and a pair of crap engines. Did those other aircraft have crap engines or crap airframes?

 

[wuzak]

The Manchester had a good airframe and a pair of crap engines. Did those other aircraft have crap engines or crap airframes?

The Blackburn B20 had the same engines, but was an experimental aircraft to prove the concept of a retracting float.

 

[cherry blossom]

The Albemarle is simple. It should have been cancelled. It was designed following a specification according to Wikipedia: "This sought a twin-engine medium bomber of wood and metal construction, without the use of any light alloys, in order that the aircraft could be readily built by less experienced manufacturers from outside the aircraft industry." It ended up as a poor medium bomber and its most notable role was towing gliders. It wasn't ideal for that as the engines tended to overheat due to the high power needed at low speed. However, the big issue was that the contractors for the Albemarle should have been making Mosquitos.

 

[Admiral Beez]

The Albemarle is simple. It should have been cancelled.

Well, that goes for all four. Forget the Botha torpedo bomber, and instead expedite the Beaufighter torpedo spec. Maybe skip the Hampden torpedo Bomber too, all hands to the Beaufighter.

 

[SaparotRob]

Install 4 J-35s on the Lerwick. That should help.

 

[pbehn]

The Halifax like the Manchester was originally supposed to be a twin and there was a proposal for a Sabre engined Mosquito. The problem was with the Sabre and Vulture engines.

 

[WARSPITER]

Not quite sure how to fix.

 

[Thumpalumpacus]

Dad used to say, "You can't polish a turd."

 

[Sabrejet]

Dad used to say, "You can't polish a turd."

...then Tesla came along with the Cybertruck.

 

[EwenS]

Well, that goes for all four. Forget the Botha torpedo bomber, and instead expedite the Beaufighter torpedo spec. Maybe skip the Hampden torpedo Bomber too, all hands to the Beaufighter.

Follow the specs that led to the Botha. Separate 1935 specs for a torpedo bomber and a general recce aircraft were merged into a single Spec 10/36 the following year to be powered by Bristol Perseus engines to fill both roles. Fulfilled by both the Botha & the Beaufort ordered off the drawing board. During the design process it became apparent that, due to rising weight, more powerful engines would be required. The Air Ministry agreed to Bristol changing to the Taurus for the Beaufort. But with production of that engine expected to be limited, Blackburn had to soldier on with the Perseus in the Botha. In service the Botha came to be intended as the GR aircraft and the Beaufort as the TB. So the Botha was on a hiding to nothing before it flew. But such was the need for aircraft, any aircraft, its development was allowed to proceed. The Botha also had a few handling problems initially. But despite the high loss rate it fulfilled a useful training role allowing better types to remain on the front line.

The Beaufighter came from a completely different line of aircraft development.

Beaufighter arose from a 1938 Bristol suggestion of using Beaufort components and Hercules engines to create an interim fighter armed with 20mm guns pending the arrival of a successor to the Westland Whirlwind into service. While most famous as a night fighter, early aircraft also went to Coastal Command from Nov 1940 as a long range fighter and replacement for the Blenheim IVf. The idea of using it to carry a torpedo didn't arise until Dec 1941 when the RAF were looking for a successor to the Beaufort in the TB role. Development of the "Torbeau" began in April 1942 and rapidly progressed with the first arriving in service before the end of 1942.

As discussed on other threads in the past, the Hampden only became a torpedo bomber in April 1942 as a stopgap due to a shortage of Beauforts for the TB role in the U.K. Wellingtons also filled that gap in the Med from the beginning of 1942.

The success of the "Torbeau" however is linked to a complete change of tactics in CC from mid-1942 with the creation of the first strike wing at North Coates in Nov 1942. It also benefitted from the availability of improved torpedoes that could be dropped at faster speeds and greater heights than those available to the Beaufort in 1940/41.

So it is all very well saying "all hands to the Beaufighter" but first you have to decide that the Beaufort, which only reached its first squadron in Nov 1939 (just 11 weeks after the outbreak of WW2) and carried out its first mission in mid-April 1940 needs to be replaced. Anything else is just hindsight.

 

[Admiral Beez]

So it is all very well saying "all hands to the Beaufighter" but first you have to decide that the Beaufort, which only reached its first squadron in Nov 1939 (just 11 weeks after the outbreak of WW2) and carried out its first mission in mid-April 1940 needs to be replaced. Anything else is just hindsight.

My bad, I meant Beaufort to replace Botha, not the later Beaufighter

 

[EwenS]

The Albemarle is simple. It should have been cancelled. It was designed following a specification according to Wikipedia: "This sought a twin-engine medium bomber of wood and metal construction, without the use of any light alloys, in order that the aircraft could be readily built by less experienced manufacturers from outside the aircraft industry." It ended up as a poor medium bomber and its most notable role was towing gliders. It wasn't ideal for that as the engines tended to overheat due to the high power needed at low speed. However, the big issue was that the contractors for the Albemarle should have been making Mosquitos.

From "The British Aircraft Specifications File" under Spec 17/38 for the Bristol 155 subsequently transferred to AW under Spec 18/38 is worth quoting (with my emphasis):-

"To enable sources of labour and materials hitherto not extensively utilised for aircraft production to be exploited in the event of a national emergency, the Air Council will consider designs for an aeroplane whose primary characteristic is the ability to be constructed rapidly and cheaply by unskilled and semi-skilled labour. The use of composite structures of wood, metal, synthetic materials and compressed laminated wood should be investigated. It is accepted that some sacrifice in structure weight will have to be made to simplify construction but the aerodynamic design should be clean and the fullest advantage should be taken of the smooth finish obtainable with the materials which are available."

The companies the work was subcontracted to the likes of Harris Lebus (furniture manufacturers), Rover Car Co & MG Motors. Production aircraft were assembled by AW Hawksley at Brockworth, another company within the Hawker Siddeley group of companies.

Harris Lebus' major product in WW2 was the Horsa glider, construction of which was sub-contracted from Airspeed itself a De Havilland subsidiary.

Interestingly De Havilland proposed a development of the all metal DH95 Flamingo twin engined airliner for this Spec.

 

[SaparotRob]

Dad used to say, "You can't polish a turd."

Has anyone actually tried?

 

[Admiral Beez]

Has anyone actually tried?

View: https://www.youtube.com/watch?v=yiJ9fy1qSFI

 

[nuuumannn]

Attributed to the Botha, a test pilot remarked in his report that, "access to the cockpit is difficult, it should have been made impossible..."

 

[nuuumannn]

Botha: scrap entirely, get Blackburn to build Beaufighters under licence.

Beaufort: fix the damn Taurus (this was done by the time the Albacore enters service)! Otherwise, fit US Twin Wasp engines as the Australians did.

The Albemarle was a proof of concept aircraft that got a production order, it was built by firms whose efforts were not otherwise employed for war work. It wasn't meant to be a war winning contemporary bomber, but a stop gap in case British war production was interrupted. It did incorporate a novel defensive armament, with two turrets, one on top and one underneath, with a remote observer calling out position reports on enemy fighters from a glazed tail section. The top gun, a Boulton Paul Type A four-gun turret was fitted, whereas the lower turret was never fitted. A mock up was installed in the prototype only. Conclusion, can't really help the Albemarle, to do so would be a waste of resources.

The Manchester provided difficulties outside of the engines, which afflicted the type throughout its career and thankfully the changes made to the Manchester Mk.III BT308 made sure that the issues that affected the Mancherster did not affect the Lancaster. It suffered directional stability problems. On BT308 the hori stab was lengthened and taller fins were fitted, which were retro-fitted to production Manchesters, which were designated Manchester Ias. The mid upper turret, the Nash & Thompson FN.7 caused an osscilation in the rear fuselage when turned, seriously affecting the centre fin, which vibrated itself to pieces - it was wood covered in fabric. This was caused by the turret's assymetric shape. This was cured in the Lancaster with the fitting of a different mid-upper turret. The Manchester's electrical systems took some wringing out, it was quite an advanced aircraft when first conceived. Avro had never put a big-ish all-metal aircraft into production when it designed the Manchester, so hydraulic and electrical systems had to be designed from scratch, experience in which Avro at that time had little. The only experience Avro's work force had in building modern all-metal structures and their incorporated systems was building Blenheims under licence. The Manchester was a big leap in capability following Avro's previous mass production twin, the Anson I.

The Lerwick was found to be troublesome from the outset, aerodynamics-wise, both the manufacturer and the Marine Armaments Experimental Establishment agreed on its poor qualities. The only solution is to end production early on and task Saro with production of the Sunderland, which was already in production and service by the time the war begins.

The B.20 was a one-off concept demonstrator. Blackburn built Sunderlands under licence during the war, keeping its Dumbarton facility, which built the B.20 in work.

 

[Admiral Beez]

Attributed to the Botha, a test pilot remarked in his report that, "access to the cockpit is difficult, it should have been made impossible..."

While I must credit them for introducing the world's first all metal, folding wing, retractable undercarriage carrier aircraft, did Blackburn ever make a good aircraft? The superlative Buccaneer, aside. The Botha needs to improve lateral visibility, for one. What the heck was its designer thinking make a torpedo bomber where the pilot has no side to side view?

 

[nuuumannn]

One British aircraft I would make changes to, although it isn't a twin, is the Handley Page Halifax. The aircraft suffered numerous niggling issues that plagued it throughout the bulk of its career and contrary to popular belief, the switch in powerplant did not cure all of its ills. To begin with, it should receive Hercules engines from the outset, thus relieving Rolls-Royce from having to sort out the issues that the Merlin installation suffered. Changing the engines to Hercules' from the outset does away with the poorly designed nacelles, which HP was responsible for. These induced vibration in the airframe at certain power settings, which was cured by inviting Rolls-Royce to redesign the nacelles, something Rolls-Royce normally did on designs fitted with its engines.

The cooling of the engines would have been dealt with sooner if Herculeses were fitted from the outset. Merlin-engined Halifaxes underwent changes to their radiator designs owing to cooling issues, these were brought about from attempting to maintain performance at heavy loads, which resulted in higher than normal operating RPMs, causing a reduction in range owing to higher fuel consumption, aside from higher maintenance hours on Halifax engines as they were being thrashed. This resulted in increasing numbers of Halifaxes making turn-backs after take-off. This issue was related to the airframe's excessive drag and it did not go away entirely with the fitting of the Hercules engines. Halifaxes in service could not maintain the type's design speeds and range during normal operations and loads and a number of meetings were held within the Air Ministry questioning the Halifaxe's high loss rates and inability to maintain performance once the type entered squadron service.

To cure the drag issue, the basic design needs to be lightened and more streamlined from the outset, or in a massive drag reduction programme of changes, many of which were introduced through the different marks on the production line. One solution was the fitting of more powerful engines, 60 Series Merlins, but the Air Ministry deemed these to be better served in other types. Also, the rudder overbalance issue needs to be reviewed earlier. It took until mid 1943, after a first flight in 1940, soon after in the second prototype the issue was picked up - nearly three years, before it was finally cured.

 

[nuuumannn]

While I must credit them for introducing the world's first all metal, folding wing, retractable undercarriage carrier aircraft, did Blackburn ever make a good aircraft?

It depends on time period. The Blackburn interwar torpedo aircraft family, beginning with the Swift and Dart and progressing through to the Shark were all good reliable aircraft. Designer Maj F.A. Bumpus was responsible for these. Blackburn's between-the-wars flying boats were also good designs, these were the responsibility of Maj Rennie, whose idea the split fuselage flying boat concept embodied in the B.20 was. It appears the run of less than inspiring designs comes about with George Petty's ascendency as Blackburn's chief engineer, beginning with the Skua, which wasn't a terrible aircraft but was bigger than it needed to be. Petty was also responsible for the Botha and Firebrand.