AHC: 1930s/40s airforce on a budget

[tomo pauk]

...
Yup, installation packaging can be a attractive especially in an aircraft where frontal area is of vital importance. The R-1820 had a 55" diameter (2376 sq.in. frontal area), irrc, where the R-1830 was something like 48" (1810 sq.in. frontal area). That's pretty big difference in area, 3 square feet.

Considering that V-1710 and Merlin were between 5.2 and 5.9 sq.ft. (plus coolant radiator that can be fitted so that much of it's drag is very low), 3 sq ft of difference might be a serious thing for a designer. 2376 sq in.is. is 16.9 sq ft. There were reasons why Bristol Mercury was considered as a 'fighter engine' in the 1930s, and Pegasus was not - Mercury was of smaller frontal area.

Now, for the Germans - say, competition between BMW and BRAMO, before the merger, brings out V8 and V12 spin-offs of their respective radials. Being German, those engines would've probably feature side-mounted S/C and provision for the prop gun, plus Kommandogeraet. Initially, V8 of perhaps 800 PS at altitude and/or 900 PS at low level, the V12 maybe 1100 PS at atltitude, 1300 at low level (ballpark HP figures for pre-war, 87 oct)? Both 132 and 323 are phased out, there is no BMW 801.
The dirt-cheap Bf 109 becames even cheaper, the He 100 is produced.

 

[Gudestein]

He-100, designed from the onset for simplicity in production.
D-model goes without saying.

 

[EverKing]

3 sq ft of difference might be a serious thing for a designer.

Exactly what I was trying to point out. Thanks

Initially, V8 of perhaps 800 PS at altitude and/or 900 PS at low level, the V12 maybe 1100 PS at atltitude, 1300 at low level (ballpark HP figures for pre-war, 87 oct)?

Those are actually pretty impressive numbers for the time for the V12, especially on 87 oct. fuel. At the very least, I'd consider them to be more than respectable.

there is no BMW 801

Like with the non-starter of the R-2800, this makes me sad. The 801 is one of my favorite engines, just a thing of beauty.

 

[tomo pauk]

Those are actually pretty impressive numbers for the time for the V12, especially on 87 oct. fuel. At the very least, I'd consider them to be more than respectable.

Not all V12s are the same - the V12 that uses cylinders of the BRAMO 323 will have a displacement of 36 liters.

Like with the non-starter of the R-2800, this makes me sad. The 801 is one of my favorite engines, just a thing of beauty.

Oh, the R-2800 will start - 18 clinders will often beat 12, while 14 might not do it
The BMW 801 in OTL offered a preciously small advantage vs. DB-601/605 line until mid-1944 as a fighter engine, and was eclipsed after that with DB 605AS and subsequent versions. 801 was much heavier (even when the cooling system is calculated in for the DBs), used much more fuel, was draggier despite the technical advancements.

Some money-saving things:
- A gun-less bomber, a Mosquito-clone is you will. Just remeber to make bomb bay big enough from the get go.
- Have De Haviland design a fighter or two in 1930s.
- R-1820 + turbo for high-alt performance on the cheap - the R-1820 cost ~60% of a V-1710. Easy 1200 HP in 1941, from SL to 25000 ft. The R-1820 got better by early 1944 - 1350 HP.
- Tank buster/fighter-bomber on a budget - a Vee engine with provision for a 25-40 mm cannon. Air cooled Vee engine for extra survivability, just remember to protect the oil system.
- 1-engined bomber or night fighter - big radial with decent supercharging, fuselage akin to the US Avenger/HelldiverII/Sea Wulf (has bomb bay) but for crew of two, wing size as of P-47.

 

[Jukra]

If we're going on a budget for a small country I'd say building AAA is much more sensible than trying to purchase a large amount of interceptors. It's really hard to keep up with technological race with limited R&D resources while even older AA guns are useful. The key is to go for large enough guns soon enough, ie. something in 5" class for cities. Maybe deployed on rail cars for strategic mobility on land?

But even smaller caliber guns (20mm, 40mm, 3", 3,5") are useful for lower level and naturally more mobile.

AA can also operate even on second class personnel, such as women (it's WW2 era, after all), schoolboys and older reservists. AA can also function in anti-tank, anti-ship and even indirect fire mode when operating with the field armies.

Of course it's no panacea and you're going to need at least some interceptors too.

If we have domestic aircraft production one aircraft type I would focus on would be an effective high-level reconnaissance plane, in effect Ki-46 equivalent.

As for bombers, I'm not sure they're worth it. A limited number of highly trained dive bombers for anti-shipping duties and key battles on land maybe?

So, basically what I would suggest is...

..an interceptor which can also act as close escort
..a long range invulnerable reconnaissance plane for tactical, operational and strategic reconnaissance
...a dive bomber
...a huge load of AA guns of different calibers

 

[Augenis]

There is only one true answer to this. All other answers are false.

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

Lithuanian aircraft was, in general, an example of "maximize combat effectiveness while keeping the planes cheap"

 

[AdA]

Assuming 30/40s means WW2, and going for a small number of multi role aircraft with long service lives.

Fighter/Interceptor/Ground attack - P47D (multi role, unbreakable, long life)
Bomber/Recce/Torpedo Bomber/Night Fighter - Mosquito
MPA/SAR/ASW - Catalina
Observation/Liasion/Medvac/Army cooperation Fi156 Stork
Transport - C47
Trainer - T6

The P47 might seem a strange choice in terms of value for money, being a big aircraft, but they could do anything and went on to have long lives in many countries with low budgets. The corsair can do almost anything, but lacks the High Altitude capability of the P47 and would mean getting another fighter for high altitude work.

 

[AdA]

A lot of the "light" fighters were not really meant to be cheap, but to be built in small factories while the factories building the "normal" fighters were building up capacity, or to avoid bottlenecks in the production of the new engines in the 1000HP class by designing fighters that could use smaller, and readily available engines in the 600/700HP class.
Built in small series, often in low tech factories, their unit cost would probably be higher than a normal fighter built in well organized modern factory.

 

[jsb]

If we're going on a budget for a small country I'd say building AAA is much more sensible than trying to purchase a large amount of interceptors.

I'm really not sure I agree, did heavy AA really achieve anything before VT fuzes, I think 40mm Bofors with smoke generators and old 3" WWI guns to disrupt high altitude bombers would be cheaper? I would then spend most of my money on fighters, type depending on date.

Assuming 30/40s means WW2, and going for a small number of multi role aircraft with long service lives.

Fighter/Interceptor/Ground attack - P47D (multi role, unbreakable, long life)
Bomber/Recce/Torpedo Bomber/Night Fighter - Mosquito
MPA/SAR/ASW - Catalina
Observation/Liasion/Medvac/Army cooperation Fi156 Stork
Transport - C47
Trainer - T6

The P47 might seem a strange choice in terms of value for money, being a big aircraft, but they could do anything and went on to have long lives in many countries with low budgets. The corsair can do almost anything, but lacks the High Altitude capability of the P47 and would mean getting another fighter for high altitude work.

Not sure I agree If i'm budget limited for WWII, I would want to cut down types and pick cheaper aircraft.

I'm not sure you need bombers/transports/MPA with hindsight (depending on location) if you can pick high powered fighters?

Fighter/Recce - P 51 Mustang
Advanced trainer/ground attack - your 1930s fighter that's now obsolete and spare
Trainer/Liasion - DH.82 Tiger Moth

 

[Cryhavoc101]

Stand up Kahn style Aircraft factories - ie Castle Bromwich with lots of single task Machine tools - enough so that a given machine tool does not have to be re-jigged or retasked during the life time of a given production run. Therefore regardless of the aircraft you are building or its complexity a relatively unskilled worker can be utilised at most stages of the production of each Aircraft and this increases the speed of construction, reduces costs over the entire production run and can be setup in just a few years.

Russia OTL for example had Kahn and US Engineers setup such factories and train achitects as well as pucharse many 1000s of modern US machine tools in the early 30s in order to create hundreds of Locomotive and Tractor factories and these were obviosly a great sucess once retasked to make tanks etc durign WW2.

 

[Jukra]

I'm really not sure I agree, did heavy AA really achieve anything before VT fuzes, I think 40mm Bofors with smoke generators and old 3" WWI guns to disrupt high altitude bombers would be cheaper? I would then spend most of my money on fighters, type depending on date.

German FLAK did not have VT fuzes at all and shot down a mighty number of planes. Finnish flak with no VT-fuzes shot down 1106 planes in 1941-1944 against 1612 planes shot down by fighters. The difference being, of course, that like with every air force there's much more hot air in numbers of planes shot down by fighters.

The thing is, that 1929 Bofors 75mm AA gun (or equivalent) is a viable AA-weapon up to 1950's with upgrades. 1929 fighter is a toast in just a few years. In effect, up to 1945 even if we consider peacetime operations you would have to purchase several generations of aircraft (say, Bristol Bulldog-Gloster Gauntlet-Gloster Gladiator-Hawker Hurricane-Spitfire V-Spitfire XIV) to keep up to date performance. That makes lifetime costs of fighters much higher than FLAK.

And, if you want to upgrade, say, 75mm flak to 90mm one, you can recycle older guns to tanks, coastal batteries etc.

Small countries did not have the means to keep up with technological development of aircraft and thus would have to do with increasingly inferior domestic built planes (witness FAF's attempts to make domestic fighters...) or to use whatever hand-me-downs their powerful friends or frenemies are willing to sell them.

With a big country, say, France or UK or Germany the equation is different, and naturally even nowadays fighters have certain advantages over AAA and vice versa.

As for budget, here is a very rough and inaccurate attempt to calculate fighter vs. flak costs.

Here are 1941 German costs for airplanes:

Basic Price Price with engine
Me-109E 58 800 85 970

Against this 12,8cm Flakzwilling cost 202000 RM's.

If we assume roughly similar cost with heavy FLAK over time (ie 2 fighters against 1 gun) we might get up to 1945 with following "generational cost"

1929 20 Bulldogs - 10 75mm FLAK
1933 20 Gauntlets - 10 75mm FLAK
1937 20 Hurricanes - 10 90mm FLAK
1941 20 Spitfire V - 10 12,8cm FLAK
1945 20 Spitfire XIV - 10 12,8cm FLAK

As for frontline you would have for similar investment in 1945 at hand

20 75mm, 10 90mm and 20 12,8CM twin FLAK guns against 20 Spitfire XIV's.

 

[EverKing]

The P47 might seem a strange choice in terms of value for money, being a big aircraft, but they could do anything and went on to have long lives in many countries with low budgets. The corsair can do almost anything, but lacks the High Altitude capability of the P47 and would mean getting another fighter for high altitude work.

At $83,000 in 1945 (perhaps less in earlier iterations) I think the P-47 is priced out of our market for this exercise. Overall I like your concept, but I would propose replacing the P-47 with the P-43 (@tomo pauk do you have prices for the Lancer?) which still had the turbo-charger and decent high altitude performance it was just outclassed IOTL because of the amount of money thrown into advanced designs. If you want to save even more money, replace the R-1830 with the R-1820 (which may be too much of a performance loss) with provision for upgrade to a turbocharged R-2600 (which, as was previously stated, was actually less expensive than the R-1830 for a time with a 50% increase in power) as the P-44 Rocket (instead of using the failed R-2180-1). You won't quite get P-47 performance and due to the smaller internal spaces you won't have the range either, but I think the end result will be a competitive all-purpose Fighter-Bomber for several tens of thousands of dollars less per aircraft. If you use the Egg concept for the engine, you can share a common installation/cowling with the B-25/XF6F/Avenger but with different exhaust collectors and intake ducting to accommodate the Turbo. This gives you a common engine for your main medium bomber, naval fighter, torpedo-bomber, and land-fighter/bomber; simplifying training, logistics, and due to the massive numbers which would be built could ultimately reduce per-unit costs.

 

[tomo pauk]

There is only one true answer to this. All other answers are false.

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

Lithuanian aircraft was, in general, an example of "maximize combat effectiveness while keeping the planes cheap"

There is no requirement here that says 'a fighter might be 100-200 km/h slower than other fighters'. Lithuanian ANBO_IV is not an example of maximize combat effectiveness, since it can't keep with bombers of the day, let alone fighters.
If we really want a 9 cyl powered fighter that can actually catch a bomber, there was a numbe to choose, like Fokker D.XXI, Ki-27, A5M etc. My fovorite would've been the Bf 109 powered by Bristol Mercury.

Assuming 30/40s means WW2, and going for a small number of multi role aircraft with long service lives.

Fighter/Interceptor/Ground attack - P47D (multi role, unbreakable, long life)
Bomber/Recce/Torpedo Bomber/Night Fighter - Mosquito
MPA/SAR/ASW - Catalina
Observation/Liasion/Medvac/Army cooperation Fi156 Stork
Transport - C47
Trainer - T6

The P47 might seem a strange choice in terms of value for money, being a big aircraft, but they could do anything and went on to have long lives in many countries with low budgets. The corsair can do almost anything, but lacks the High Altitude capability of the P47 and would mean getting another fighter for high altitude work.

Excellent choices, very much feasible for any aircraft-producing country, excluding the P-47. The low-budget countries that got expensive US fighters (P-47, P-38, Corsair) got them without money. Fuel was not issue for hundred or so per country, either. The 18 cyl turbo powerplant was out of question for non-USA countries, too, until mid war, thus leaving 1930s and early ww2 without a fighter, unless something other is produced and/or purchased.
I'll toss in the An-2 - shows that one 9 cyl radial of 1000 HP can give a good service.

 

[tomo pauk]

German FLAK did not have VT fuzes at all and shot down a mighty number of planes. Finnish flak with no VT-fuzes shot down 1106 planes in 1941-1944 against 1612 planes shot down by fighters. The difference being, of course, that like with every air force there's much more hot air in numbers of planes shot down by fighters.

The thing is, that 1929 Bofors 75mm AA gun (or equivalent) is a viable AA-weapon up to 1950's with upgrades. 1929 fighter is a toast in just a few years. In effect, up to 1945 even if we consider peacetime operations you would have to purchase several generations of aircraft (say, Bristol Bulldog-Gloster Gauntlet-Gloster Gladiator-Hawker Hurricane-Spitfire V-Spitfire XIV) to keep up to date performance. That makes lifetime costs of fighters much higher than FLAK.

And, if you want to upgrade, say, 75mm flak to 90mm one, you can recycle older guns to tanks, coastal batteries etc.

Small countries did not have the means to keep up with technological development of aircraft and thus would have to do with increasingly inferior domestic built planes (witness FAF's attempts to make domestic fighters...) or to use whatever hand-me-downs their powerful friends or frenemies are willing to sell them.

With a big country, say, France or UK or Germany the equation is different, and naturally even nowadays fighters have certain advantages over AAA and vice versa.

...

Do we know how much there was fighter aircraft in Finland vs. how many cannons? The AAA can't help over enemy-held airspace.
Germany was awash with heavy and light AAA (10000 of heavy pcs in 1944 in service), yet, once the 8th AF LR fighters killed LW fighters, US bomber losses went into ~2% vs. ~10% befor the LR escorts were employed.
Recruiting high school boys, wousewives and PoW into crews for AAA is false economy, that was one of main factors in declining of LW Flak arm from 1942 on - from 4000 heavy shells per kill to 16000 (16 thousand) im 1944.

(@tomo pauk do you have prices for the Lancer?)

This:

 

[jsb]

The P47 might seem a strange choice in terms of value for money, being a big aircraft, but they could do anything and went on to have long lives in many countries with low budgets. The corsair can do almost anything, but lacks the High Altitude capability of the P47 and would mean getting another fighter for high altitude work.

From the above what does a P47 give that nearly twice the number of P51 would not do better?

I want the P40 from 1942 for my air force, even if I'm sure that's a typing error!

 

[AdA]

I'm really not sure I agree, did heavy AA really achieve anything before VT fuzes, I think 40mm Bofors with smoke generators and old 3" WWI guns to disrupt high altitude bombers would be cheaper? I would then spend most of my money on fighters, type depending on date.


Not sure I agree If i'm budget limited for WWII, I would want to cut down types and pick cheaper aircraft.

I'm not sure you need bombers/transports/MPA with hindsight (depending on location) if you can pick high powered fighters?

Fighter/Recce - P 41 Mustang
Advanced trainer/ground attack - your 1930s fighter that's now obsolete and spare
Trainer/Liasion - DH.82 Tiger Moth

There is no requirement here that says 'a fighter might be 100-200 km/h slower than other fighters'. Lithuanian ANBO_IV is not an example of maximize combat effectiveness, since it can't keep with bombers of the day, let alone fighters.
If we really want a 9 cyl powered fighter that can actually catch a bomber, there was a numbe to choose, like Fokker D.XXI, Ki-27, A5M etc. My fovorite would've been the Bf 109 powered by Bristol Mercury.



Excellent choices, very much feasible for any aircraft-producing country, excluding the P-47. The low-budget countries that got expensive US fighters (P-47, P-38, Corsair) got them without money. Fuel was not issue for hundred or so per country, either. The 18 cyl turbo powerplant was out of question for non-USA countries, too, until mid war, thus leaving 1930s and early ww2 without a fighter, unless something other is produced and/or purchased.
I'll toss in the An-2 - shows that one 9 cyl radial of 1000 HP can give a good service.

In the Real world the P47 would only be sold to countries allied with the US (It was used by the Brazilian AF in Italy in 1944).
In an ideal world, the P47 can replace 3 types. An interceptor, a tactical fighter and a ground attack aircraft. The P51 can do the same, but while it is the equal of the P47 as a fighter, its not as good as a fighter bomber/attack aircraft. An was even less an export type than the P47 during the war.
The An-2 is a post war aircraft.
The best deal on the market as a multi-role aircraft that just might be sold to a neutral country would probably be the P36G

 

[Driftless]

Not calculated into the budget so far: cost of basic and advanced training, and regular flight operations including routine maintenance. If you are running a tight budget, do you press for a planes that are easier to learn to fly and are lower maintenance? That may buy you some more air frames and pilots, or do you go the opposite direction - relatively smaller number of more advanced planes and a smaller cadre of real professional pilots?

 

[Augenis]

There is no requirement here that says 'a fighter might be 100-200 km/h slower than other fighters'. Lithuanian ANBO_IV is not an example of maximize combat effectiveness, since it can't keep with bombers of the day, let alone fighters.

What do you mean it can't keep up with the other planes of the day? With a maximum speed of 220 mph, it's faster than its main competitors in the region - Letov Š-28, Hawker Audax and Armstrong Atlas.

 

[AdA]

At $83,000 in 1945 (perhaps less in earlier iterations) I think the P-47 is priced out of our market for this exercise. Overall I like your concept, but I would propose replacing the P-47 with the P-43 (@tomo pauk do you have prices for the Lancer?) which still had the turbo-charger and decent high altitude performance it was just outclassed IOTL because of the amount of money thrown into advanced designs. If you want to save even more money, replace the R-1830 with the R-1820 (which may be too much of a performance loss) with provision for upgrade to a turbocharged R-2600 (which, as was previously stated, was actually less expensive than the R-1830 for a time with a 50% increase in power) as the P-44 Rocket (instead of using the failed R-2180-1). You won't quite get P-47 performance and due to the smaller internal spaces you won't have the range either, but I think the end result will be a competitive all-purpose Fighter-Bomber for several tens of thousands of dollars less per aircraft. If you use the Egg concept for the engine, you can share a common installation/cowling with the B-25/XF6F/Avenger but with different exhaust collectors and intake ducting to accommodate the Turbo. This gives you a common engine for your main medium bomber, naval fighter, torpedo-bomber, and land-fighter/bomber; simplifying training, logistics, and due to the massive numbers which would be built could ultimately reduce per-unit costs.

With the option to use the same engine in locally built/assembled Dakotas and Catalinas.
The modified P43 would take the fighter/fighter-bomber/Recce/attack roles.
A modified locally built A20 with the same engine could take the bomber/torpedo bomber/night fighter role.
Apart from the Stork and a trainer, we would have a one engine air force.
Sounds like a good plan.

 

[DrakonFin]

Do we know how much there was fighter aircraft in Finland vs. how many cannons?

Some quick estimates (somebody correct me if I am obviously missing something):

About 550 fighter aircraft used in first line service by the FAF, vs. c. 1000 light, c. 350 medium, and c. 350 heavy AA guns used by all branches of the Finnish military.