WI Panic Fighter 1938?



This picture purports to be of one of the 26 Mile Master M26 fighters converted. Single seat, six guns in the wings. The previous image I posted does look like the prototype Miles Kestrel with added guns!
 
I am a bit concerned about engine upgrade for these airframes. Bristol Mercury in 1938 was nearing growth limit, with power stagnating around 800 hp. Quite different from 1500hp Allison V-1710 which transformed P-36 to formidable P-40.
Using Bristol Pegasus or Hispano-Suiza 12Y as replacement will help only marginally as these engines were also limited to 1000 hp.
Using Allison V-1710 may be fine, but it was about 50% heavier, likely leaving no space for armament even if it would be possible to install much heavier engine at all.

Structural problems of wings likely mean SAI.207 can not be fitted with combat flaps. Also, it was below-average climber.
It was certainly a below-average climber when compared with then-current fighter that were slightly heavier, but featured much more powerful engines. Combat flaps were not installed at anything in this era of interest (1930-38), so IMO that's a moot point. Granted, wing was a bit on a small side, someting like what Yak-3 or SAI.403 had would've been a better choice.
Bristol Mercury was making 840-890 HP, on 87 oct fuel, dependin on version, by late 1930s. The V-1710 is in 1938 still in development, thus representing a gamble for the 1930-38 era. It will need plenty of modifications, strengthening and 130 grade fuel to make factory-aprooved 1500 HP.

Well, summarizing..if we are allowed any airfoil, hybridizing P-36/P40 fuselage with the wings of Ki-43 may give an ideal fighter/interceptor. Maneuverable, with 12.7mm weapon mount from beginning, and engine upgrade-able up to 1500 hp.
Realistically, i can imagine Nakajima covertly selling the wrecked Ki-43 11th prototype airframe in 1939 to make up the losses after been ordered to give up on it, may be after in-flight disintegration due clear-air turbulency (instead of making more mods and succeeding IOTL with 13th prototype). The Ruralia engineers reverse-engineer the Fowler flaps and overall wing profile, and re-make it in A2024 alloy - to be mated with P-36Q fuselage which is already license-produced. The result is super-maneuverable and long-range P-36, although slightly heavier than original Ki-43 (510 km/h speed and 17 m/s climb rate).
The airfoil of the Ki-43 is of 18% thickness at root, ie. far draggier than the 15% thick wing on the P-36, let alone a 13% thick wing of a Spitfire or 14% thick wing of the Bf 109. If we're to choose wing at after-1938 era to be featured in pre-1938 A/C, there are plenty of better wings in all the countries.
Let's not over-estimate Ruralia's capability in aerodynamics and materials - panic fighters that worked rely on proven, off-the-shelf stuff, even for big countries.

This is a French 'almost a panic fighter' - the VG-33: link
 
The airfoil of the Ki-43 is of 18% thickness at root, ie. far draggier than the 15% thick wing on the P-36, let alone a 13% thick wing of a Spitfire or 14% thick wing of the Bf 109.
Any idea what airfoil the CW-21 used? I found one listing for
'Curtiss CW-19 Spl' but that's not so helpful. Curtiss used mostly Clark Y before going to the 2215

And since I found a nice cutaway view showing the four cowl guns, everyone else can enjoy
 
I am a bit concerned about engine upgrade for these airframes. Bristol Mercury in 1938 was nearing growth limit, with power stagnating around 800 hp. Quite different from 1500hp Allison V-1710 which transformed P-36 to formidable P-40.
Using Bristol Pegasus or Hispano-Suiza 12Y as replacement will help only marginally as these engines were also limited to 1000 hp.
Using Allison V-1710 may be fine, but it was about 50% heavier, likely leaving no space for armament even if it would be possible to install much heavier engine at all.

.
The OP stated this was a panic fighter, the Pegasus, 12Y and Mercury are immediately available mature designs that meet the immediate needs for such a fighter and have been widely produced under licence in a number of countries. While they limit the long term potential of an aircraft as an interceptor, once that point has been reached the resulting aircraft will still be viable as ground attack aircraft.
 
marathag,

That beautiful cutaway drawing of the CW-21 structure is my best argument for a small nation with no metal construction experience to follow Lockheed's 1932 example. The simplicity of fabrication available with monocoque plywood outweighs any imagined weight penalty. Unquestionably the use of casein adhesives, widely available in the late thirties, combined with mittel-European weather would limit airframe durability out in the rain but they would certainly last as long as combat operations would (hypothetically) require. Design of an airplane is much more realistic than the sudden creation of a complex, skilled and demanding industry.

As for an engine actually available 'over the counter' with spares obtainable worldwide, the Napier W-1430 Lion had demonstrated supercharged performance well in excess of 1300 HP. Easily de-rated to the topic specified 1000HP. Basic weight of this engine was less than any contemporary V-12 I'm aware of.

Dynasoar
 
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marathag,

That beautiful cutaway drawing of the CW-21 structure is my best argument for a small nation with no metal construction experience to follow Lockheed's 1932 example. The simplicity of fabrication outweighs any imagined weight penalty. Unquestionably the use of casein adhesives, widely available in the late thirties, combined with mittel-European weather would limit airframe durability out in the rain but they would certainly last as long as combat operations would (hypothetically) require. Design of an airplane is much more realistic than the sudden creation of an industry.

Plenty of room for fuel tanks


Going to the Duramold(Phenol formaldehyde):cool: limits that, as casein was used for attaching the sub-assemblies.

Resorcinol-formaldehyde glue was being worked on in the UK, but was used as an adhesive for friction material to steel for clutches, not woodworking til midwar
It was less brittle than the Phenol resin, but had no real gap filling ability and still needed to be clamped under pressure, and didn't need the elevated temperature to cure

Epoxy had been discovered in Germany in the '30s, bit was not looked into as an wood adhesive

But again, we are looking for a structure that will hold together for a few years.
 
View attachment 391244

Here is a picture of the Miles Kestral/Master emergency light six gun fighter from 1940. The Kestrel first flew in1937 and therefore realistically this fighter version could have been available from 1988
This is the picture before I altered it. It's the original Kestrel Trainer prototype. Even as is it could have served as a (grossly under armed) emergency fighter.

 
If a "panic fighter" has a service life of 12-24 months before the structure becomes unsafe for full use, that is more than good. Between combat loss, other non-combat damage etc I wonder what the full service life of a "regular" WWII fighter was, and also after 18-24 months of war expect something better to come on the scene. I think everyone would agree that rifle caliber (.30 cal/7.62mm) armament is inadequate. For a panic fighter against other fighters and twin engine bombers, would 4x .50 cal/12.7mm be adequate (not ideal) given the limitations on this "panic fighter" - given the requirements and the engine limitations, adding cannon is nice but may compromise performance too much.
 
For a panic fighter against other fighters and twin engine bombers, would 4x .50 cal/12.7mm be adequate (not ideal) given the limitations on this "panic fighter" - given the requirements and the engine limitations, adding cannon is nice but may compromise performance too much.
That is one of the reasons I opted for the 12Y for the Kestrel Fighter. It was designed to allow the use of an engine mounted 20mm as was done in the French MS-406 fighter.
 
Dear Marathag,
Thanks for posting that beautiful cutaway drawing of a Curtiss-Wright 21.

We wonder how many different airplanes could be built on CW-21 jigs?
WI a Curtiss-Robertson-Wright CR-2 Coupe, 2-seater, side-by-side, 350 hp (CW R-760, 7-cylinder radial) engine visited Ruralia during a sales tour?
WI the Ruralia Air Force bought a few kits for CW-19 basic trainers? How soon before civilian customers start demanding a 4-seater variant of CW-19?
Why am I envisioning an airplane resembling a Yak 18T?

WI Ruralia bought CW-21 jigs and patterns to produce a series of airplanes based on CW-21?
How many CW-21 parts could be bolted-backwards to CR-2 basic trainers?
How many CR-2 parts could be bolted-forward to CW-21 fighters?
How many CW R-540-7 parts could be bolted-forward? How many parts could be bolted-backwards from R-2600 (twin row, 14 cylinder) or R-3350 (twin row, 18 cylinder radial engines)?

The goal is to build multiple different engines and airframes with the least tooling. Ideally, different generations and models share the same bolt patterns, allowing a battle-damaged CW21 fighter to “borrow” an outer wing panel from a CW-19 trainer.
 
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Dear Marathag,
Thanks for posted those beautiful cutaway drawings of Lockheed Vegas.
Your description of chemical engineering is also helpful.

WI a scion of a Ruralia timber magnate family returns from Stuttgart University with a duelling scar, a chemical engineering degree and lab experience formulating early versions of epoxy resin?
WI he is seconded to the family-owned canoe factory that is struggling with a shortage of birch bark?
WI he develops a canoe made of wooden ribbons bonded together with epoxy resin?

WI his cousin returns with a chemistry degree and a Masters’ Thesis on nylon 6?
WI the second cousin is loaned to the family-owned fish-net factory?
 
That is one of the reasons I opted for the 12Y for the Kestrel Fighter. It was designed to allow the use of an engine mounted 20mm as was done in the French MS-406 fighter.
Not just on the MS 406 - other french fighters took advantage of the feature, so did Czech and Yugosav designs, so did the Soviets with their M-100, -103, -105 and -107 engines (that were sharing the lineage with the Hispano engines).
The HS 12Y was probably the best non-Merlin engine for fighters before 1939, and it was available either as direct purchase or as a license-produced engine (Czech and Soviets took that path).
 
My what if version of the Westland Whirlwind has it equipped with 12Ys instead of the more often talked about Merlin. In my opinion the 12Y is the engine Rolls Royce hoped the Peregrine would be and as the Soviets proved still had a fair amount of development potential, at least for 2nd rank air forces.

I think the German's might have something to say about it being the best non Merlin engine though. (Hears loud murmurs about the DB601 coming from over the North Sea)
 
If we are using resin technology may I point to Gordon's Aerolite from which they made a Spitfire fuselage just in case aluminium ran short.
 
My what if version of the Westland Whirlwind has it equipped with 12Ys instead of the more often talked about Merlin. In my opinion the 12Y is the engine Rolls Royce hoped the Peregrine would be and as the Soviets proved still had a fair amount of development potential, at least for 2nd rank air forces.

I think the German's might have something to say about it being the best non Merlin engine though. (Hears loud murmurs about the DB601 coming from over the North Sea)
Hence the qualifier 'before 1939' - apart from one-offs, prototypes etc, the DB 601 was being installed in the Bf 109s from spring of 1939, with airframe production outstripping the engine production (similar situation happened with Ki 61 and Merlin Mustang) in that year.
Peregrine was still a bit better than HS 12Y, it was able to run well both on 87 (+6.75 psi for 885 HP at ~5km) or 100 oct fuel (+9 psi boost; around 1000 HP at 3-4 km), was smaller, but without a provision for a prop cannon. Most importantly, it was later in the game than Merlin, let alone the HS 12Y.
For a what-if - the HS12Y is license produced in Britain instead of the hopeless Alvis Pelides, or, even better, instead of the Napier Dagger.
 
Hence the qualifier 'before 1939' - apart from one-offs, prototypes etc, the DB 601 was being installed in the Bf 109s from spring of 1939, with airframe production outstripping the engine production (similar situation happened with Ki 61 and Merlin Mustang) in that year.
Peregrine was still a bit better than HS 12Y, it was able to run well both on 87 (+6.75 psi for 885 HP at ~5km) or 100 oct fuel (+9 psi boost; around 1000 HP at 3-4 km), was smaller, but without a provision for a prop cannon. Most importantly, it was later in the game than Merlin, let alone the HS 12Y.
For a what-if - the HS12Y is license produced in Britain instead of the hopeless Alvis Pelides, or, even better, instead of the Napier Dagger.
Later HS 12Z was able to run on 100 octane fuel, delivering some 1300 hp. ;)
 
Dear Marathag,
Thanks for posted those beautiful cutaway drawings of Lockheed Vegas.
Your description of chemical engineering is also helpful.

WI a scion of a Ruralia timber magnate family returns from Stuttgart University with a duelling scar, a chemical engineering degree and lab experience formulating early versions of epoxy resin?
WI he is seconded to the family-owned canoe factory that is struggling with a shortage of birch bark?
WI he develops a canoe made of wooden ribbons bonded together with epoxy resin?

WI his cousin returns with a chemistry degree and a Masters’ Thesis on nylon 6?
WI the second cousin is loaned to the family-owned fish-net factory?
It's amazing with all the developments in Chemistry during the 19th Century, none it was in making better glues than Collagen and Protein based glues from animals. You know, hides, milk or blood that were from hundreds or even thousands of years.

There were many missed opportunities after all the uses of Coal Tar were being looked into, and really nobody was looking into making faster curing, stronger UV resistant and waterproof glues till the 1920s

Phenols were pretty obvious, but missed when the first uses were for doing solid castings, Bakelite before WWI.

They aren't ideal, being brittle, and needing both pressure and heat to cure. catalyzing two part Epoxy Resin was missed in the '30's, and polyester resin during WWII .

Another choice would be Urea formaldehyde, discovered in the 1880s, but not used for wood til it gradually got more popular during the '20s. this was used for Marine glues, like for PT boats

Any of those early glues could have been used to do a process similar to what Fairchild did, but in the 1930s.

yes, would be life limited, but airplanes were not being made to last a hundred years, technology was changing so very quickly from WWI onwards

Wood would be cheap, and fast building, plus not requiring a specialized workforce,

Now for Curtiss in St. Louis. The CW-19 wings were hardly changed from all the various types from the CW-19 to -23. Most all the 'CW' numbers from 1 through 16 were wooden wings and steel
tube fuselage craft from Travel-Air, a company that had Walter Beech, Clyde Cessna and Lloyd Stearman in it, and left after they were 'merged' into Curtiss Wright, and started their own light airplane companies.

Doing a version of the -19 as a four place does not stretch credibility. The wings, and area ahead of the instrument panel where hardly changed.

Look what Walter Beech did after WWII

Same length, slightly less wingspan, with a few changes, like the Vee Tail, would be known as the Bonaza

-19 not a bad design influence for light, all-metal aircraft
 
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