Minimum fighters mayhem

[SwampTiger]

The thing for the French is - what to buy with limit being 1 or 2 fighter designs? The MS.406 was of lacklustre performance (barely better than the Japanese fixed-U/C fighters with radial engines, less than Hawk 75s and He 112B with indifferent Jumo 210G), while also requiring inordinate amount of manhours to produce (IIRC same as the two-engined Pozez 63 series, or 50% more than D.520). Dewoitine D.500/501 line is hopeless, though a version with retractable U/C and better radiator would've been probably useful for 1940.
UK was buying Defiants and Gladiators along with Hurricanes and Spitfires, with Whirlwind and Beaufighter in pipeline. So I'd say that French need several designs to make up for shortcomings of their fighter's line-up.

French politics forced the issuance of military contracts to a variety of firms throughout the country. Each firm wanted to build its own designs. The administration was just getting hold of procurement and manufacturing chaos in the late 1930's. The defense establishment should have concentrated on two or three designs in each category and required manufacturers to bid on building these chosen designs. However, hindsight is easier than real life. Isn't politics grand!

 

[CalBear]

In 1930s and 1940s (but not limited to) many companies were trying to design, manufacture and sell 'light fighters' - aircraft that will not be using latest engines, but that will rely on small size and weight in order to became performers. For many reasons, those designs rerely suceeded.
The task is here to 'design' fighters for the late 1930s/early 1940s, for each country & company historically capable of that, that will be using second- or even third-rate engines. Small stature, but still hopefully capable to provide good service. Armament, materials, technology and aerodynamics of the day to be used.
Engine power will be limited to 750 HP for up to year of 1939, 850 HP for 1940, 990 HP for 1941 and on. Just historical engines, up to two designs can be offered per country - on with liquid-cooled engine, another for air-cooled.
Armament of at least 4 LMGs, or 2 HMGs, or 1 cannon. Range/radius sufficient for current doctrine of the choosen air force/service.

Good service against what? Aircraft of the same year or just straight up?

In 1941 all you need to do is pull one 20mm and you have the A6M (950hp engine 2x20mm cannon, 2x7.7mm mg). Wait until January 1, 1942 (1,050 hp 1x.50cal, 1x30 cal) and you can plug in the P-36, except now you can add a second .30 cal). Same goes for the original, as first flown in April of 194o, P-40 (1,050 HP, 357 mph, except it has 2x.50 cal and no .30 cal and no cannon)

 

[sonofpegasus]

Who could design and build a British Bloch 700? The Bristol Mercury would be the engine of choice for this aircraft. How much better than the Miles Kestrel would it be?

 

[tomo pauk]

Who could design and build a British Bloch 700? The Bristol Mercury would be the engine of choice for this aircraft. How much better than the Miles Kestrel would it be?

People at Supermarine, De Haviland or Percival - the ones with racing pedigree. Bristol probably, they were offring a neat fighter armed with 4 cannons (though powered by Hercules), AM said 'thanks, but no thanks'.
Miles Kestrel used a very thick wing profile, unlike the aircraft from those companies. So the performance shoulf be better.

Good service against what? Aircraft of the same year or just straight up?

Same year, plus another year. With engine upgrade(s) another 2-3 years. Eg. the Germans can throw in He-100 powered with Jumo 211G for 1938/39, then move to HS 12Y in 1940. British can offer a fighter with RR Kestrel in 1939/40, move to Peregrine in 1941

In 1941 all you need to do is pull one 20mm and you have the A6M (950hp engine 2x20mm cannon, 2x7.7mm mg). Wait until January 1, 1942 (1,050 hp 1x.50cal, 1x30 cal) and you can plug in the P-36, except now you can add a second .30 cal). Same goes for the original, as first flown in April of 194o, P-40 (1,050 HP, 357 mph, except it has 2x.50 cal and no .30 cal and no cannon)

I will try to avoid un-symetrical recoil, that will happen with just one cannon per side
We don't need 1050 HP in order to make 350-ish mph. VG-33 did it on 860 HP, the SAI.207 and 403 were a bit faster on even less power. 1000-1100 HP with a V12 engine of early ww2 vintage was making severla fighters go 360-370 mph.
P-36 is too slow for my liking, especially for the purposes of this thread.

 

[SwampTiger]

See Air Ministry Specification F 5/34. Bristol Type 146, Gloster F 5/34, and Vickers Venom using Bristol Perseus, Mercury and Aquila respectively.

 

[TonyA]

I will try to avoid un-symetrical recoil, that will happen with just one cannon per side

Never seen this referenced before. The only A/C with dissimilar wing armament I'm aware of is the Beaufighter. Is such a thing a real problem?

 

[SwampTiger]

The British could have the Vickers Venom with Bristol Mercury and four Vickers .50/12.7x81 ordered by December 1935, building by August 1936 and in squadron service by late 1938. Send two or three squadrons to Singapore in 1939, build in India and Australia starting in 1938 if you could get by the Colonial Office veto of local manufacture.

 

[marathag]

In 1941 all you need to do is pull one 20mm and you have the A6M (950hp engine 2x20mm cannon, 2x7.7mm mg). Wait until January 1, 1942 (1,050 hp 1x.50cal, 1x30 cal) and you can plug in the P-36, except now you can add a second .30 cal). Same goes for the original, as first flown in April of 194o, P-40 (1,050 HP, 357 mph, except it has 2x.50 cal and no .30 cal and no cannon)

Curtiss would build Hawk 75 however the customer wanted, the Cowl guns could be optioned with either .30, 6.5 Madsen, 7.35 Madsen or 8mm Vickers or .50 Browning, .50 Vickers or 11.35 Madsen, and one or two 30 class in each wing, one 50 Vickers(50 Browning not listed for wings)or one 23mm Madsen or 20mm Oerlikon in a gondola under each wing, and one gun from the cowl could be replaced with a gun camera. This from the Curtiss 1939 sales booklet, that also listed small bombracks as an option, 10 30 lbs or 6 50 lbs bombs Flare dropping mechanisms, and optional Armored seatback for the pilot

 

[Peabody-Martini]

Curtiss would build Hawk 75 however the customer wanted, the Cowl guns could be optioned with either .30, 6.5 Madsen, 7.35 Madsen or 8mm Vickers or .50 Browning, .50 Vickers or 11.35 Madsen, and one or two 30 class in each wing, one 50 Vickers(50 Browning not listed for wings)or one 23mm Madsen or 20mm Oerlikon in a gondola under each wing, and one gun from the cowl could be replaced with a gun camera. This from the Curtiss 1939 sales booklet, that also listed small bombracks as an option, 10 30 lbs or 6 50 lbs bombs Flare dropping mechanisms, and optional Armored seatback for the pilot

You highlight what one of the problems is. With export fighters things like superchargers and the latest engines are deleted if they were ever there in the first place, so the trade offs become larger. Performance, pilot survivability and armament, you only get two.

 

[marathag]

You highlight what one of the problems is. With export fighters things like superchargers and the latest engines are deleted if they were ever there in the first place, so the trade offs become larger. Performance, pilot survivability and armament, you only get two.

With the Hawk 75, even had choice of P&W or Wright power, and there were versions with better supercharger sections. Curtiss could have put in an engine with a two stage unit, but P&W was still trying to take care of a surging issue in 1939 with their new in-house design intercooled 2 stage SC.
Army was tossing a lot of money at Turbocharging, not superchargers for radials.

There is one more metric in your list, Money. The Hawk wasn't cheap in 1939, but would quickly be seen as a bargain for what later fighters would cost.

 

[tomo pauk]

You highlight what one of the problems is. With export fighters things like superchargers and the latest engines are deleted if they were ever there in the first place, so the trade offs become larger. Performance, pilot survivability and armament, you only get two.

Export fighters also have other shortcomings, like vast majority of the countries not even been allowed to buy certain stuff. Eg. US government was in one mood yesterday, another today, then another tomorrow.
Each engine for aircraft from early 1930s have had supercharger installed (bar some left-overs, like the BMW VI or Fiat A.30): Cyclone, Twin Wasp, Kestrel, HS 12Y, Jumo 210. Granted brand new engines are hard to come by for anything but the country of origin.

With the Hawk 75, even had choice of P&W or Wright power, and there were versions with better supercharger sections. Curtiss could have put in an engine with a two stage unit, but P&W was still trying to take care of a surging issue in 1939 with their new in-house design intercooled 2 stage SC.
Army was tossing a lot of money at Turbocharging, not superchargers for radials.

There is one more metric in your list, Money. The Hawk wasn't cheap in 1939, but would quickly be seen as a bargain for what later fighters would cost.

Curtiss was unable to cater for needs of both US and French AFs with Hawk in 1939/40. Hence coming out with indigenous fighter has merits, a third or fourth country gambling on availablility of it will loose the gamble.
P-36 was never considered as a light fighter, not even in 1941.

 

[marathag]

Curtiss was unable to cater for needs of both US and French AFs with Hawk in 1939/40. Hence coming out with indigenous fighter has merits, a third or fourth country gambling on availablility of it will loose the gamble.
P-36 was never considered as a light fighter, not even in 1941.

That's true, but closest to what the IJN/IJA had in the Zero and Oscar.

CW-21 at the St. Louis plant wasn't exactly choked with orders, so that made sense. Per the older thread, everyone should recall that the Demon grew from the CW-19

Here is the family

• CR-2 - Curtiss-Robertson prototype with strut-braced wing and unfaired undercarriage (two built) 1930

• 

• Model 19L - prototype with cantilever wing, spatted undercarriage and Lambert R-266 engine (one built)

• Model 19W - prototype with Warner Super Scarab engine (one built)

• Model 19Q - Lycoming R-680-B2 Seaplane design (none built)

• Model 19R Fighter - militarized version with tandem seating, weapons mountings, and Wright J-6-7 engine (23 built)

• Model 19R Long Range Trainer - Extra center mounted 35 gallon aux tank pod. One fixed forward gun, one rear manned gun.

• Model 19R Light Bomber - Two .30 cal guns with two A-3 bomb racks. (563 lb)

• 

• Model 19R Photo Reconnaissance - Two bottom mounted camera ports.

• Model 19R Attack (special) - single seat with wing mounted guns (none built)

• Model 19R Advanced Trainer - Pratt&Whittney R-760-E2 or R-975-E3 engine choices.

• Model 19R Seaplane - proposed 1936 variant of the 19Q (none built)

• Model A19R - military trainer offered to USAAC (three built, one later converted to CW-22)

• Model B19R - projected civil version of Model A19R (none built)

• Model C19R - Amphibian standard trainer R-975-E3 (none built)

• Model C19R - Amphibian advanced trainer (none built)

• Model C19R - Amphibian fighter - One forward gun, one manned gun (none built)

• Model C19R - Amphibian photographic aircraft - Fairchild KB-3 camera mount

• Model C19Z - Standard Amphibian or Seaplane trainer - Pratt & Whitney Wasp SC-G

• CW-23 - advanced military trainer with Pratt & Whitney R-1340 engine and retractable undercarriage (one built)

 

[tomo pauk]

That's true, but closest to what the IJN/IJA had in the Zero and Oscar.

CW-21 at the St. Louis plant wasn't exactly choked with orders, so that made sense. Per the older thread, everyone should recall that the Demon grew from the CW-19
...

The CW-19 seems interesting. Size is neither too big nor too small.
A fighter of same span/length/wing area, powered, say, with Twin Wasp Junior in production by 1938 and service by foreign AFs 1939, and then the version with turbo in production in 1940-42 (by then also using 100 oct fuel). Retractable U/C, single seater. I've suggested The TW Junior beasuse it fits power limit per year, plus it was pretty small engine, 44 in diameter.

 

[marathag]

The CW-19 seems interesting. Size is neither too big nor too small.
A fighter of same span/length/wing area, powered, say, with Twin Wasp Junior in production by 1938 and service by foreign AFs 1939, and then the version with turbo in production in 1940-42 (by then also using 100 oct fuel). Retractable U/C, single seater. I've suggested The TW Junior beasuse it fits power limit per year, plus it was pretty small engine, 44 in diameter.

Howard Hughes got near 1000HP on the Twin Wasp in his H-1 Racer on the new 100 Octane over the standard 700HP. 352mph over a closed course(where he ran it out of fuel and crashed) and an average 327 mph on a transcontinental record run from Burbank to Newark

The CW-19 and H-1 were very similar in size and wing area, the short wing H-1 was 138 sq.ft and long wing 191 sq.ft the CW-19 had 174sq.ft

The long wing version was set to carry up to 280 gallons of fuel, while the CW-19 had 48 gallons, with an option for 35 more

 

[tomo pauk]

Howard Hughes got near 1000HP on the Twin Wasp in his H-1 Racer on the new 100 Octane over the standard 700HP. 352mph over a closed course(where he ran it out of fuel and crashed) and an average 327 mph on a transcontinental record run from Burbank to Newark

The CW-19 and H-1 were very similar in size and wing area, the short wing H-1 was 138 sq.ft and long wing 191 sq.ft the CW-19 had 174sq.ft

The long wing version was set to carry up to 280 gallons of fuel, while the CW-19 had 48 gallons, with an option for 35 more

The limit on engine power is set here for it's reasons - let the 'normal' fighters and bombers have spanking new engines, the 'minimum fighters' will use 2nd tier engines, that can run happiliy on 87 oct fuel too. Easily available engines simplify procurement problems, especially for foreign buyers, while performance can/will be attained through small size and weight. Light fighters cost less money to purchase and operate.

From the 1st post:
"In 1930s and 1940s (but not limited to) many companies were trying to design, manufacture and sell 'light fighters' - aircraft that will not be using latest engines, but that will rely on small size and weight in order to became performers.
...
Engine power will be limited to 750 HP for up to year of 1939, 850 HP for 1940, 990 HP for 1941 and on. Just historical engines, up to two designs can be offered per country - on with liquid-cooled engine, another for air-cooled."

100 oct fuel was not available for any country by just the flick of a switch, especially if we talk about thousands of galons the AF will use daily in case of war, and especially before 1940s. An OTL example - French used the HS-12Y/31 on the VG-33 because it was able to be run on 87 oct fuel, unlilke the /45, used on D.520, that required 100 oct fuel, granted the /45 made more power at all altitudes.

 

[marathag]

T

From the 1st post:
"In 1930s and 1940s (but not limited to) many companies were trying to design, manufacture and sell 'light fighters' - aircraft that will not be using latest engines, but that will rely on small size and weight in order to became performers.
...
Engine power will be limited to 750 HP for up to year of 1939, 850 HP for 1940, 990 HP for 1941 and on. Just historical engines, up to two designs can be offered per country - on with liquid-cooled engine, another for air-cooled."

100 oct fuel was not available for any country by just the flick of a switch, especially if we talk about thousands of galons the AF will use daily in case of war, and especially before 1940s. An OTL example - French used the HS-12Y/31 on the VG-33 because it was able to be run on 87 oct fuel, unlilke the /45, used on D.520, that required 100 oct fuel, granted the /45 made more power at all altitudes.

But just with tuning and better fuel, the Twin Wasp does future proof your design, since it was at 700HP before 1939. With the tweaks available for that since 1936, you can get right to that HP limit with ease, while not effecting reliability

It's about the best powerplant choice for the minimum fighter, and it never got the improvement in supercharging. As it was, the big differences between the different versions was being geared or direct drive, and different impeller ratios.
P&W never finished development the two stage supercharger for the TWjr.

 

[Peabody-Martini]

A plane that might interest you, the Curtis SC Seahawk

https://en.wikipedia.org/wiki/Curtiss_SC_Seahawk

 

[tomo pauk]

But just with tuning and better fuel, the Twin Wasp does future proof your design, since it was at 700HP before 1939. With the tweaks available for that since 1936, you can get right to that HP limit with ease, while not effecting reliability

It's about the best powerplant choice for the minimum fighter, and it never got the improvement in supercharging. As it was, the big differences between the different versions was being geared or direct drive, and different impeller ratios.
P&W never finished development the two stage supercharger for the TWjr.

Don't get me wrong, I like the Twin Wasp, and I'm of opinion that there was even more scope for improvement of power than it was used up in ww2. Examples of the J.22, DB-7 and P.66 show that performers can be made around it, even if those used 2nd, or perhaps 3rd best possible R-1830. The R-1830 got improvement in supercharging - for example, by mid-1941 it was also available as the 1st operational engine with 2-stage supercharger in the world (in series production), and it was outfitted with turbocharger in both bomber and fighter application - but that will be beyond scope for 1939 and '40.

I've suggested the TWjr with turbo, but probably it would'e been cheating, since there was no operational A/C that flew that combination. On the other hand, moving from the TWjr (used here in 1938-39-40) to the 'full' TW (1941) should not be much of a hussle.

A plane that might interest you, the Curtis SC Seahawk

https://en.wikipedia.org/wiki/Curtiss_SC_Seahawk

That plane interests me very much - it was the 1st, and probably the only Western aircraft that used turbocharger with air-cooled turbine. That allowed for compact installation of the turbocharger system. Interest is even greater since there is no surviving example of it nowadays, and no cutaway or schematics that depict the particular installation.
As for the A/C itself, it was neither small nor light, for example the wing size was in the ballpark with Hawker Typhoon, or almost twice the size of the Polikarpov I-16.

 

[Draconis]

.

That plane interests me very much - it was the 1st, and probably the only Western aircraft that used turbocharger with air-cooled turbine. That allowed for compact installation of the turbocharger system. Interest is even greater since there is no surviving example of it nowadays, and no cutaway or schematics that depict the particular installation.

Could you elaborate on the turbocharger turbine cooling? I'm trying to picture how it would be different than the turbocharger installation in a P-47 or B-17.

 

[tomo pauk]

Could you elaborate on the turbocharger turbine cooling? I'm trying to picture how it would be different than the turbocharger installation in a P-47 or B-17.

Turbine blades were hollow, and passages fed fresh air to the blades in order to cool them. Allows for turbines being far less susceptible to the hot exhaust gasses' temperatures, that in return allows placement of turbocharger next to the engine, rather than to some location feets or yards away. That again means that designer need to allocate far less of internal volume to the propulsion system, meaning smaller and lighter aircraft that will perform better. Germans employed such system on the BMW 801J engines, used on Ju-388, plus on some of their jets (meaning that expensive and hard-to-come-by metals were not needed). Ford proposed the system for their stillborn V-1650 V12 engine (not to be confused with Packard Merlin V-1650). Bell proposed a version of P-63 with same turbocharger from the Curtiss SC, remained in 'paper stage'.
A retrofit of such turbo on existing A/C with turbocharger will probably not give the same results as with aircraft designed from ground-up for that, since there will not be any 'shrinking' of the resulting A/C. With P-47, there is also a thing of re-ballancing the aircraft. Retrofitting on, say, P-40, P-51, F4F/F2M and/or A-20 would've been a good thing IMO.