From Bristol Bulldog to Spitfire, Handley Page Heyford to Lancaster - the revolution in aircraft design in the late 1930s

[whart57]

If we take 1933, the year Hitler took power in Germany, as our starting point, then the RAF had just introduced the Handley Page Heyford into Bomber Command service

 

 

In the fighter squadrons the Bristol Bulldog had been in service for three years and would remain in service a few more

 

 

Both of these aircraft were recognisably similar to the planes the RAF had at the end of World War 1 in the same roles. Yet the Spitfire and Lancaster that entered service five and eight years later were so different it could be said there was a revolution in plane design. Or was there? Or was it natural evolution. And did a similar process take place in other countries?

 

That's what this topic is about, I hope others will join in and contribute

[The Lurker]

A quick google of 1930's German  Military Aircraft suggests a similar evolution; once Germany began rearming they started with biplanes; various Arado, Albatros and early Heinkel fighters, although I have not picked up on a bomber.

 

I would have thought that military necessity pushes technology quicker than peacetime (look at the development of planes in WW1 as an example) and growing rivalry prompted an arms race which speeded up the development.

 

At the same time, I believe the desire to win air races in the interwar years meant that fighter designs had something to draw on. 

[Barry Ten]

I think there was a rapid evolution in the early to mid thirties. The DC-3 is only two years younger than the Heyford but looks much more modern. The B17 dates from around the same time, also a much more sophisticated machine, in fact so complex compared to its predecessors that it was almost unflyable until the concept of the checklist had been devised. 

Edited January 11, 2023 by Barry Ten
slight correction

[Hroth]

The most important work a Heyford undertook was in the Daventry experiment which demonstrated the feasibility of what was initially called "Radio Direction and Finding" (RDF), later better known as Radar....

 

[whart57]

It might be worth compiling a short list of innovations brought into aircraft design during the 1930s. Off the top of my head are:

• Aluminium replacing wood and canvas
• Three-bladed multi-pitch propellors
• Liquid cooled inline aero-engines
• Fuel injection replacing standard carburation
• Enclosed cockpits
• Retractable undercarriage

Obviously not every innovation was incorporated in every plane. The radial engine in particular was still much used right up to the end of the piston engined era. And of course, famously, the use of wood made a comeback with the De Havilland Mosquito.

 

Some 1930s designs were fairly conservative. This Italian Fiat design was not introduced to service until 1939 and did, briefly, feature in the Battle of Britain, operating out of Occupied Belgium

 

 

The Italians also used them as escort fighters over Malta.

 

 

Edited January 11, 2023 by whart57

[whart57]

1 hour ago, The Lurker said:

A quick google of 1930's German  Military Aircraft suggests a similar evolution; once Germany began rearming they started with biplanes; various Arado, Albatros and early Heinkel fighters, although I have not picked up on a bomber.

 

That is possibly because Germany was allowed to have fighters for self defence but not bombers. I don't know, it would be in the small print of the Treaty of Versailles. Did those planes pre-date Hitler's rejection of the Versailles Treaty?

[woodenhead]

Listen to the first 30 seconds of this video, by all accounts the Bristol Blenheim should have blitzed the German defences at the beginning of the war and still been the most potent weapon of the cold war.  Only one other aircraft has beaten it for speed - the SR71.

 

[whart57]

They describe the Daily Mail  as "prestigious" as well!

[woodenhead]

Something else to consider, at the start of the 1930s - bi-planes, by 1937 Heinkel were pursuing jet propulsion and the first prototype was the Heinkel He 178 in 1939 albeit a rather underpowered aircraft.

 

When you consider the speed of development it is staggering - at the end of WW1, whilst there were mechanised weaponary in the form of tanks, guns and planes, the battlefield was still the place where the fighting took place, Zepellin raids were an annoyance and did cause death but it was nothing on the scale of what was to come.  In WW2 which took terror beyonds the fields of battle, by the end of the war that ability had developed to unstoppable unmanned missiles and single bombs capable of flattening large parts of cities.  Less than 10 years later we had developed the capability to destroy civilisation across the globe with just a few bombs.

[Kickstart]

Some things had just become viable in scale.

 

For example the Junkers J1 was an all metal monoplane with a liquid cooled inline engine built in 1915 (but not accepted into service). The 1920s had very little development (the Bristol Fighter was still in RAF service into the 1930s) for various reasons, with development getting more advanced in the 1930s

 

All the best

 

Katy

[whart57]

It may be a little narrow to consider only military aircraft. The inter-war years were also when civil aviation first started. Civil airliners went through a similar revolution. Consider the mainstay of Imperial Airways in the early 1930s, the HP42

 

 

And then consider Douglas' radical DC2 of only a couple of years later

 

 

The DC3 which followed on a couple of years later on again consolidated the design and some remained in service until the 1970s.

 

 

 

[IWCR]

 

One  german  biplane  contempary with  the  Heyford was the Heinkel 59,  this  was  still in  service  throughout  most  of  the  war  in  its  floatplane  variant.  Originally  a  maritime  bomber  or  torpedo  bomber  its  later  use  was  as  an  air  sea  rescue  floatplane  or  trainer.

 

Pete

[Tartaruga]

I think that the date you give is key. Prior to 1933 the world was coming out of a recession and with the advent of Hitler rearmament started in earnest which enabled money to be spent on new designs.

You mention the FIAT but the Gloster Gladiator trumped the original Spitfire for approval from the RAF in 1937 ,but Mitchell refined the design to what we recognise today, and the Gladiator was still in service at the begining of the war. 

Poland was one of the largest spenders militarily in Europe and had some modern designed aircraft but by 1939 their frontline fighters were obselete being designed in the late 20's and produced in 1931. The P11 was a monoplane while RAF were still using biplanes. 

 

[J. S. Bach]

6 hours ago, whart57 said:

If we take 1933, the year Hitler took power in Germany, as our starting point, then the RAF had just introduced the Handley Page Heyford into Bomber Command service

 

 

 

I can see the Lancaster in the Heyford.

[burgundy]

Quite interesting to think about the rate of change of a new technology. The early years tend to see very radical development before improvements settle down to be much more incremental. You can apply this to railways as well as to aviation. If you apply it to IT, you can speculate where we are on the curve at present.   

Best wishes 

Eric  

[Ramblin Rich]

12 minutes ago, burgundy said:

Quite interesting to think about the rate of change of a new technology. The early years tend to see very radical development before improvements settle down to be much more incremental. You can apply this to railways as well as to aviation. If you apply it to IT, you can speculate where we are on the curve at present.   

Best wishes 

Eric  

Quite true, we went from the Wright brother's hop in 1903 to supersonic flight within 50 years. Moon landing and commercial supersonic transport in less than 70. We've definitely tailled off in the years since.

[Ozexpatriate]

It all starts with Sir Bennett Melvill Jones whose 1929 paper "The Streamline Airplane" presented to the Royal Aeronautical Society was seminal.

 

Some may find this paper, "On the planning of British aircraft production for the Second World War and reference to James Connolly" interesting.

 

It goes into great detail with the air ministry's struggle to define specifications that could keep pace with the revolutionary developments taking place in the mid-1930s - including how "Specification F.7/30" utterly failed and resulted in the purchase of Gloster Gladiators which entered service in the RAF in 1937 as a front line fighter!!!

 

It also explains how the Boulton-Paul Defiant came to be and why so many Fairey Battles* were built.

 

* Incomprehensible in some respects, yet not of course in context.

 

 

[Ozexpatriate]

7 hours ago, whart57 said:

Aluminium replacing wood and canvas

The essential change here is a revolutionary structural change.

 

To achieve the 'streamlined' form factor, the girder design of the wood+fabric designs where the fabric surface was not load bearing changed to one in which "a metal skin carried a high proportion of the loading, both in bending and torsion"*

 

* From the paper linked above.

 

[pH]

9 hours ago, woodenhead said:

Something else to consider, at the start of the 1930s - bi-planes, by 1937 Heinkel were pursuing jet propulsion and the first prototype was the Heinkel He 178 in 1939 albeit a rather underpowered aircraft.

Jet propulsion becoming a practical proposition caused another step change in aircraft (specifically fighter) design. Then-current development of new piston-engined fighters in (at least) the UK and Germany was stopped. This was the last in a series of highly-rated prototypes that were developed but never made it into production for the RAF:

https://en.wikipedia.org/wiki/Martin-Baker_MB_5

 

The company went on to specialize in a specific type of aircraft equipment.

 

 

 

[Ozexpatriate]

1 hour ago, pH said:

This was the last in a series of highly-rated prototypes that were developed but never made it into production for the RAF:

Looks like a Spitfire and a P-51 had a baby.

 

Similarly cancelled with the advent of jets, the Supermarine Spiteful/Seafang and CAC Kangaroo.

[J. S. Bach]

2 hours ago, pH said:

Jet propulsion becoming a practical proposition caused another step change in aircraft (specifically fighter) design. Then-current development of new piston-engined fighters in (at least) the UK and Germany was stopped. This was the last in a series of highly-rated prototypes that were developed but never made it into production for the RAF:

 

The U. S. A-1 Skyraider by Douglass Aircraft was another exception, first f;own in March of 1945; the Japanese never felt its sting, for which they should be thankful. The A-1 served into the Vietnamese war; a long service life. I was present when the A-1 was "piped over the side" at NAS Lemoore upon its official retirement from US Navy service. We (the ground support shop that I was attached to) got that plane to use as a training aid for plane captains.

 

https://en.wikipedia.org/wiki/Douglas_A-1_Skyraider

 

 

[Ozexpatriate]

3 hours ago, J. S. Bach said:

The U. S. A-1 Skyraider by Douglass Aircraft was another exception

Dave, as I'm sure you know, there were a bunch of piston-engined aircraft (new and WW2-era) that were deployed by western navies (long after their airforces moved to jets) while navies experimented with reliably operating jets on aircraft carriers.

 

The USN deployed aircraft like the Grumman F8F Bearcat from 1945 through 1963. The F4U Corsair flew with the USN as late as 1953, as did the Martin AM Mauler (which the Skyraider replaced). Similarly the RN flew the Hawker Sea Fury until 1953.

 

The RN flew propeller aircraft from Fairey for a while. The Fairey Firefly was used until 1956. The RN also used the Fairey Gannet for a long time, but that was a turboprop. The Skyraider may well have been the last combat, piston-engined aircraft in US or British service but it was one of many for a long time.

 

None of these piston designs began after 1945. Even the Skyraider flew before the end of WW2.

 

Edited January 12, 2023 by Ozexpatriate

[F-UnitMad]

13 hours ago, J. S. Bach said:

I can see the Lancaster in the Heyford.

As the Heyford was built by Handley Page, it's the Halifax you should be able to see. 😉

[whart57]

12 hours ago, Ozexpatriate said:

Some may find this paper, "On the planning of British aircraft production for the Second World War and reference to James Connolly" interesting.

 

 

It is. One factor to come out though is the confusion over strategy. During the 1920s British planning worked on the basis of the next war being with France, a sort of old habits dying hard mindset really given Britain had last fought France over a century earlier. Only in 1935 did planning turn to thinking of Germany as the most likely enemy.

 

More pertinently was the tension between the needs of fighters for home defence and bombers to attack and defeat the enemy. In most countries the strategic doctrine that bombing cities would demoralise a civilian population and provoke them into revolting against their government took hold. In the early 1940s Goering and "Bomber" Harris would demonstrate that that strategy was baloney. The Blitz and the sustained bombing which completely flattened German cities from 1943 to 1945 had the opposite effect in that it united civilians behind their governments.

 

There is a tendency to see fighter development in the 1930s as being Spitfire vs Messerschmidt 109, the two technically most superior protagonists. The Hurricane probably only made it to 1939 because it was, correctly, judged to be easier to maintain and repair under combat conditions as well as being able to be manufactured by the likes of car factories. However there were a dozen or more other designs in front line service in 1939 and 1940. France, Italy, the Netherlands, Poland and Russia all had domestic aero companies that had produced front-line fighters. Most were performing at around 300 mph top speed - like the Hurricane - and most were under-armed compared to the British and German fighters. The designers were well aware of that but they were working with inferior power plants and couldn't accept the weight of more guns - and ammunition - and sourcing the 20mm cannon they really wanted was nigh impossible.

 

Occasionally one of the "inferior" designs would have a feature that would even things up a bit - the Fokker D.21 for example could do very tight turns and dive like a Stuka, which evened things up a little when they came up against Me109s - but it's instructive that the only use the Luftwaffe had for captured fighters was training.

 

Which really leads to the conclusion that it was the Rolls Royce Merlin that won the Battle of Britain, not the Spitfire.

[woodenhead]

29 minutes ago, whart57 said:

 

More pertinently was the tension between the needs of fighters for home defence and bombers to attack and defeat the enemy. In most countries the strategic doctrine that bombing cities would demoralise a civilian population and provoke them into revolting against their government took hold. In the early 1940s Goering and "Bomber" Harris would demonstrate that that strategy was baloney. The Blitz and the sustained bombing which completely flattened German cities from 1943 to 1945 had the opposite effect in that it united civilians behind their governments.

 

 

And yet to this day Russia still bombs cities into destruction as a tactic to demoralise citizens.

 

I guess though that it depends on whether said target country has the backing of NATO aligned countries to keep the armed forces supplied, the poor Syrian populous never really had that as it was their own 'government' who instigated it.