'Minimum' fighter A/C for 1937-45?

[naraic]

But why not just build more Hurricanes and use the merlins from Battles etc for them? Then put the second rate engines in a twin engine light bombers to replace the Battle?

If the British are to purposefully build a second line fighter I would suggest a decision to build an export monoplane fighter. Then the British government might block the sale of merlin engined planes in the mid 30s.

A Kestrel design could then emerge and have a production line. In the late 30s anything with a production line wasn't going to be closed in Britain.

 

[Driftless]

If the British are to purposefully build a second line fighter I would suggest a decision to build an export monoplane fighter. Then the British government might block the sale of merlin engined planes in the mid 30s.

A Kestrel design could then emerge and have a production line. In the late 30s anything with a production line wasn't going to be closed in Britain.

Maybe instead of a Merlin, one of the home-grown radials?

 

[Lascaris]

Rolls Royce sold the French a Merlin III licence for 50,000 pounds in 1939 (plus a 200 pound fee for every engine built). If you are friendly to Britain that's a bargain price arguably, less than the cost of four Hurricanes. A Merlin III powered IK-3 or B-135 would be good for 560-570 km/h. Then if you survive long enough to switch to more powerful versions of Merlin you should be set for the whole war.

 

[naraic]

Rolls Royce sold the French a Merlin III licence for 50,000 pounds in 1939 (plus a 200 pound fee for every engine built). If you are friendly to Britain that's a bargain price arguably, less than the cost of four Hurricanes. A Merlin III powered IK-3 or B-135 would be good for 560-570 km/h. Then if you survive long enough to switch to more powerful versions of Merlin you should be set for the whole war.

Its interesting the British view to arms sales in the 30s.

In 1935/1938 the Merlin was key technology you couldn't even buy a plane using a Merlin engine. It was key technology. If you want to buy fighters from Britain you were offered a Gloster Gladiator.

In 1939 everything and licenses too were on sale (but delivery could be dodgy) to help fund emergency scaling up of production.

50,000 +200 per unit doesn't sound like much but if the French built in any kind of appreciable volume it could have been a massive deal for Roll Royce. At this time Rolls Royce was building multiple factories and needed the money for investment badly.

 

[Driftless]

Would you classify the Arsenal VG.3x series as minimum fighters? Wooden semi-monocoque construction, single 20mm, with 4 x7.5mm machine guns. Several engines were considered: H-S 12Y, Allison V-1710, and the Merlin.

 

[brazen]

The MB.2 with the proposed retractable undercarrage sounds like it would fit the requirement well, simple construction would mean that it's easy to maintain and fit with whatever engine was required.

 

[Reggieperrin]

(Fighter) Airframe design was beyond the curve in many countries, and in a lot of companies in countries that were on forefront of aero business. Poland - P.11 was okay for mid-1930s, while P-24 was obsolete both from wing, engine and undercarriage point of view. Yugoslavia: IK-2 was obsolete on arrival, it took them forever to came out with IK-3. France - D.500 and 510 went obsolete quickly, D.520 and de-bugged MB.150 series were too late, the MS.406 looked right but was hopeless in service. MB.150 series was also under-performers in 1940. Czechoslovakia and Italy - too long in love with biplanes, the engine installation on G.50 and MC.200 looked like a generation older than what Ki-27 had. UK - in the era of Hurricane why bother with yet another biplane fighter (Gladiator)? Japan - Ki-43 was probably 3-4 years lagging behind comparable European fighters.



Different countries will have different industries and different plans. Poland and Czechoslovakia were in a good shape to make affordable fighters that still perform well in second half of 1930s with engines they had in production, however the fighter airframes were obsolete, and new airfrmes were too late. Similar was the case for Italy, temporary saving grace was that Germany kicked France and UK from European ground war by mid-1940. Japan was making no fighters of note in the 1930s, even if the Ki-27 was a decent fighter for the engines it used and while having a fixed U/C. UK needed to cover a lot of their overseas territories, in practice it meant that they were using biplanes in 1940 and 1941 in Med. People often mention the Miles fighter designs - Miles company was favoring wings of thickness-to-chord ratio of 20-22% (!) at root, including the M.20, that made Hurricnae's wing a thin wing.
France was a country that was making expensive second rate aircraft, including the MS.406 and 'flying house' bombers.

The more I have read about this period the more horrendously complicated it turns out to be. The mid thirties seems to have been when a lot of previously competitive countries and companies just fell off the pace without realising it, and when a lot of previously sensible things became basically suicidal. An example being two-row radial engines, where many manufacturers had successfully made them with only two bearings, indeed Hispano had previously tried building a three bearing one and it was a failure - but from 1935 any two-row radial without a centre bearing was doomed. Even the much vaunted Hispano v12s had little future after 1935 due to flimsy construction.

Same with the ‘tried and tested’ structure of tubes and wires and fabric and lots of little bits of riveted sheet metal that people were deeply in love with because it was supposedly low risk and easy to repair and non-strategic and whatever. After 1935 the reality was that if you had a decent number of rubber presses and a good design you could press out plane parts so quickly and cheaply that as to make those other factors irrelevant, and the advantages only multiplied when labour became short due to conscription. If you had no presses you basically had no aircraft industry, but an arts and crafts movement.

In terms of a minimum fighter, I’m not sure there is much improvement to be had over OTL. Depending on the mission requirements and industry capabilities a Bf109, Hawk 75, Hurricane, Spitfire or Macchi 200 with a second rate engine is probably going to be as good or better than a second rate fighter with a second rate engine, and I doubt there would be much cost difference. My guess is that the 109 would be cheapest to manufacture but the cost of getting it from the Nazis would be high.

 

[naraic]

In terms of a minimum fighter, I’m not sure there is much improvement to be had over OTL. Depending on the mission requirements and industry capabilities a Bf109, Hawk 75, Hurricane, Spitfire or Macchi 200 with a second rate engine is probably going to be as good or better than a second rate fighter with a second rate engine, and I doubt there would be much cost difference. My guess is that the 109 would be cheapest to manufacture but the cost of getting it from the Nazis would be high.

A while back I looked at unit costs 1939 of Spitfires Hurricane and Gladiators.

While I can't guarantee the numbers are accurate (as they were for specific orders rather than just general costs) the Hurricanes and the Gladiators cost about the same and the Spitfire cost half again as much. While the Gladiator was clearly the second line fighter of the three the cost benefit was non existant.

In fact one can argue that the Hurricane was the British minimum fighter in the late 30s and the early 40s while the Gladiator was a mistake.

 

[tomo pauk]

The more I have read about this period the more horrendously complicated it turns out to be. The mid thirties seems to have been when a lot of previously competitive countries and companies just fell off the pace without realising it, and when a lot of previously sensible things became basically suicidal.

Some countries made relatively modern bombers in second half of 1930s (Poland, Italy) while their fighters remained backward. A lot of companies indeed found the task of switching from strutted and braced biplanes (or monoplanes) to cantilever monoplanes to require far more effort than expected.

Even the much vaunted Hispano v12s had little future after 1935 due to flimsy construction.

Indeed, flimsy construction (it took Soviets to make the blocks thicker, reinforcement here and there, addition of the low gear for the S/C, and the best M-105 were still under 1300 HP despite the high-octane fuel and engine gaining 50% more weight), bad S/C (the -45 gotten a better unit, but too late) and 2-valve cylinder head for crying out loud.

In terms of a minimum fighter, I’m not sure there is much improvement to be had over OTL. Depending on the mission requirements and industry capabilities a Bf109, Hawk 75, Hurricane, Spitfire or Macchi 200 with a second rate engine is probably going to be as good or better than a second rate fighter with a second rate engine, and I doubt there would be much cost difference.

Hurricane with a second rate engine will not work - it took a best engine in the world to make it a performer, and it was not competitive vs. Bf 109E or Spitfire with similar power figures. From Hawker we'd probably want the fuselage of the Fury mated to a suitably small monoplane wing with retractable U/C - ie. a true Fury monoplane.
Conversely, from British and German perspective of 1939, Macchi 200 was already powered by a second rate engine.
Hawk 75 - at least what Americans were using - have had an engine in-between the Fiat A.74 and Merlin or DB 601A. Installation of the V-1710 to make a P-40 evened the playing field a lot there, even if the V-1710 was running late vs. DB 601A and especially vs. Merlin.
A Spitfire with a lesser engine is an interesting idea. What might not work for foreign buyer is it's a bit late appearance, and non-availability before 1942 (for the British allies).
Bf 109 with lesser engine was made, it used the Jumo 210 engine before the 109E version came about. With Jumo 210G, it made about 315 mph; granted, the weapon set-up was weak, usually just two LMGs. A Bf 109 with Kestrel -> Peregrine -> Merlin would've been interesting.

 

[LostCosmonaut]

If the issue is not just cost, but a "limited tech" fighter that can be built locally, the Swedish FFVS J-22 is probably the best that could be done by countries with limited aircraft industries in the period and no access to top of the line V12 engines.

I really like the J22; the R-1830 is around since the mid-30s (although a bit anemic compared to later versions), and if you're worried about that use four rifle caliber mgs in the first version will save a couple pounds. Biggest issue is probably high altitude performance.

A bit outside the topic, but the US building a J22 clone in the 1930s instead of the P-35 and P-36 would be interesting...

 

[naraic]

A Spitfire with a lesser engine is an interesting idea. What might not work for foreign buyer is it's a bit late appearance, and non-availability before 1942 (for the British allies).

I'm afraid that this is unlikely to work as a minimum fighter for the reason that the Spitfire airframe (without engine) was already more expensive than a Hurricane. Due to that if you build a Spitfire airframe it's not a minimum fighter no matter what engine you put in.

 

[tomo pauk]

I'm afraid that this is unlikely to work as a minimum fighter for the reason that the Spitfire airframe (without engine) was already more expensive than a Hurricane. Due to that if you build a Spitfire airframe it's not a minimum fighter no matter what engine you put in.

Thus this thread

 

[Peg Leg Pom]

Hurricane with a second rate engine will not work - it took a best engine in the world to make it a performer, and it was not competitive vs. Bf 109E or Spitfire with similar power figures

A Hurricane with a Napier Dagger was proposed as an emergency fighter and would probably have been adequate against all but the 109's. There's no reason it couldn't have been offered as a export fighter to small nations Britain wanted to butter up anytime from 1937 on. The airframe's there, as is the engine currently being built for the Hawker Hector Army Co Operation aircraft.

 

[CB13]

As others have also commented, my best guess would be that as long as the DB601 evolves per OTL, the concept of a "minimum fighter" may be fatally flawed. Specifically, with the evolution of the OTL DB601, it ensures that the OTL German Me-109e can always choose, where, when and how to engage said "minimum fighter" (by which I mean that the pilot of the "minimum fighter" will almost always be surrendering both speed and altitude to their German opponent) which negates both its relative fighting ability and therefore its suitability for task. I had never thought about it until the question was asked (which makes it a great question), but in reality what was needed was doctrine built around air supremacy where larger numbers were exchanged for fewer truly spectacular fighters. JMHO.

 

[Peg Leg Pom]

As others have also commented, my best guess would be that as long as the DB601 evolves per OTL, the concept of a "minimum fighter" may be fatally flawed. Specifically, with the evolution of the OTL DB601, it ensures that the OTL German Me-109e can always choose, where, when and how to engage said "minimum fighter" (by which I mean that the pilot of the "minimum fighter" will almost always be surrendering both speed and altitude to their German opponent) which negates both its relative fighting ability and therefore its suitability for task. I had never thought about it until the question was asked (which makes it a great question), but in reality what was needed was doctrine built around air supremacy where larger numbers were exchanged for fewer truly spectacular fighters. JMHO.

This assumes that the nation building or buying the minimum fighter will be threatened by one of the major powers. The nation may for example be in South America and not need first rate European standard aircraft, just something reasonably modern that they can maintain with their existing facilities.

 

[sparky42]

A Hurricane with a Napier Dagger was proposed as an emergency fighter and would probably have been adequate against all but the 109's. There's no reason it couldn't have been offered as a export fighter to small nations Britain wanted to butter up anytime from 1937 on. The airframe's there, as is the engine currently being built for the Hawker Hector Army Co Operation aircraft.

I suppose that requires the UK to be even thinking about such a design which they weren't in '37.

 

[Reggieperrin]

A while back I looked at unit costs 1939 of Spitfires Hurricane and Gladiators.

While I can't guarantee the numbers are accurate (as they were for specific orders rather than just general costs) the Hurricanes and the Gladiators cost about the same and the Spitfire cost half again as much. While the Gladiator was clearly the second line fighter of the three the cost benefit was non existant.

In fact one can argue that the Hurricane was the British minimum fighter in the late 30s and the early 40s while the Gladiator was a mistake.

It would be very interesting to know how the production costs changed for hurricane vs spitfire as production developed. It wouldn’t surprise me if that cost difference shrank a bit, since 1939 was still quite early in the manufacturing run for Spitfire while the Hurricane factories had been running a while

Indeed, flimsy construction (it took Soviets to make the blocks thicker, reinforcement here and there, addition of the low gear for the S/C, and the best M-105 were still under 1300 HP despite the high-octane fuel and engine gaining 50% more weight), bad S/C (the -45 gotten a better unit, but too late) and 2-valve cylinder head for crying out loud.

Bf 109 with lesser engine was made, it used the Jumo 210 engine before the 109E version came about. With Jumo 210G, it made about 315 mph; granted, the weapon set-up was weak, usually just two LMGs. A Bf 109 with Kestrel -> Peregrine -> Merlin would've been interesting.

Hispano crankshaft was apparently also flexible as a politicians principles, Swiss versions had to have it tripled in to sustain power.

An OTL bf109d or hawk75 would, IMO, be just fine for many purposes, not least because they apparently functioned much as intended and had most of the essential things designed in.
There is always a temptation to get lost in trying to achieve perfection but for this scenario it seems particularly pointless. Any ‘perfect’ airframe would immediately attract a top-line engine and promoted into being a spitfire/109E replacement, likewise spending a ton of effort trying to perfectly optimise a second rate airframe with a second rate engine is effort wasted from more useful things like getting it into mass production or designing the next generation of aircraft.
If one looks at some of the planes even major air forces were using in 1940 like Gladiator, fiat biplanes, PZL P.24, A5M & Ki-27, I-15 & I-16, the variety of semi-functioning crap the AdA had to put up with, then 109D or Hawk75 seem like quite nice options to me. Not perfect for sure, but a lot of pilots and commanders would have prayed to have such an upgrade, the AdA both prayed and paid cash for it.

Similarly stick an R-1830, Kestrel or Jumo into the Hurricane or Macchi and it seems like they would be not fine but not absolutely terrible either, which is better than some of the OTL choices people had to make. I would agree the Hurricane is getting elderly but then it was a low-risk evolutionary design in 1935 so keeping it going by 1940 is a stretch even with a top-line engine. A gelded hurricane with a feeble engine vs gloster Gladiator? Not great either way, but I can see someone choosing the Hurricane and stripping out half the guns. At least that way they get some experience operating a modern-ish fighter, although that cuts both ways.

Alternatively - gelded hurricane , Bf109D etc vs Gloster 4/34 with an R-1830 or similar in the front? That would be a very tempting gamble although there is a risk that the Gloster is as problematic to field/produce as the spitfire or MB.150, or that it distracts Gloster/Hawker from spamming out proper Hurricanes. And if one is developing such a nice aircraft why not put in a little more effort, scale it to a Hercules/R-2180 or similar and try for Spitfire/109E performance?

 

[AJE]

Even the much vaunted Hispano v12s had little future after 1935 due to flimsy construction.

The 12Z and VK107 still got up to 1,800 HP, and that was enough to last the French and Soviets to the jet age, so at least it was good enough for them.

It would be very interesting to know how the production costs changed for hurricane vs spitfire as production developed. It wouldn’t surprise me if that cost difference shrank a bit, since 1939 was still quite early in the manufacturing run for Spitfire while the Hurricane factories had been running a while

From a long set of PMs I made on an ideal WWII fighter:

Spoiler: Man-hours data

This disparity is clearly visible when you look at the numbers. In January 1940, it took 15,000 man-hours to build a Spitfire 1A and 9,000 to build a Bf 109E. By 1942, that gap had only widened. The Bf 109F needed only 4,000 man-hours to build whereas the Spitfire Mk V required 13,000.

Spitfire Mk 1A January 1940: 15,000
Bf 109E January 1940: 9,000
Spitfire Mk V 1942: 13,000
Bf 109F 1942: 4,000
Source (and also found here)

Fighters:
Spitfire January 1940: 15,200
Hurricane January 1940: 10,300
Whirlwind January 1940: 26,600
Tornado January 1940: 15,500
Bombers:
Battle January 1940: 24,000
Whitley January 1940: 52,000
Wellington January 1940: 38,000
Manchester January 1940: 52,100
Halifax January 1940: 76,000
Stirling January 1940: 75,000
Source (it's at the very bottom at footnote 89 or just page-search "man-hours")

P-51 1941-42: 8,666
P-51 1944: 2,639
F-86 1948-1950: 24,793
F-86 1951: 5,153
Source (pages 722-729)

B-17: 35,400 1943, 18,600 1944
B-24: 24,800 1943, 14,500 1944
B-25: 14,800 1943, 10,700 1944
C-46: 113,000 1943, 49,500 1944
C-54: 142,100 1943, 62,600 1944
P-38: 14,800 1943, 9,600 1944
P-47: 22,200 1943, 9,100 1944
Source (page 333, along with many other production measures)

Getting the new fighter into service was a slow and laboured process however. A C.202 required 22,000 man-hours to complete, while it took Alfa Romeo over a year to put the DB601A-1 into production as its licence-built RA.1000 R.C.41-I Monsone- and afterwards its factory was able to produce only 60 engines per month. Despite these setbacks, the Regia Aeronautica finally had a fighter that was clearly superior to the RAF’s Hurricane and on a par with the Luftwaffe’s Bf 109. The C.202 saw its first combat over Malta on 1 October when seven 9 Gruppo aircraft conducted a fighter sweep over the island.

Macchi C.202 (likely late 1941): 22,000
Source (page 67)

“The C.202 also required 20,000 man-hours to produce compared to just 4,500 for the Bf 109.”

Macchi C.202: 20,000
Source (page 20)

On recommendations of German observers from their Ruestungs und Kriegsproduktion Stab (the Armaments and War Production Staff), further G.55 manufacture was dispersed across Monferrato, enabling workers in various towns and villages throughout the area to construct different specific parts, which were then brought together for rapid assembly in Turin. German efficiency measures also reduced Centaur fabrication from 15,000 to 9,000 man-hours per finished airplane. In all, 274 of the latest Fiats were produced by war’s end.

Fiat G.55 (1943): 15,000
Fiat G.55 (1944): 9,000
Source (pages 41-42)

He-219-A-0 (only 11 A/C Built): 9,000 Man Hours

Bf-109E (1939): 12,000
Bf-109E (1940): 6,000~
Bf-109F (1941): 7,800~
Bf-109F (1942): 4,000
Bf-109G (1942): 5,700~
Bf-109G (1943): 4,000
Bf-109G (1944): 2,000
P-38 (First Aircraft): 360,000
P-38 (500th Aircraft): 17,000
P-38 (10,000th Aircraft): 3,800
Avro Lancaster (1941): 51,000
Avro Lancaster (1945): 20,000
Il-2 Sturmovik (Early): 9,500
Il-2 Sturmovik (Late): 5,900
B-2A Spirit (First A/C): 3,500,000
B-2A Spirit (Northrop Estimate for 11th B-2): 1,000,000
Airbus 300 (First A/C): 340,000
Fiat G.55 (Early Production): 15,000
Bf-109: 5,000
F-16A (1984): 29,000
F-16C (1989): 45,000
F-22 Mid Fuselage: 60,000
Spitfire: 15,200
Hurricane: 10,300
Whirlwind: 26,600
Tornado: 15,500
Battle: 24,000
Whitley: 52,000
Wellington: 38,000
Manchester: 52,100
Halifax: 76,000
Stirling: 75,000
B-17 (1942): 54,800
B-17 (Seattle Boeing ; 1943): 35,400
B-17 (Seattle Boeing ; 1944): 18,600
B-24 (Consolidated San Diego; 1943): 24,800
B-24 (Consolidated San Diego; 1944): 14,500
B-25 (North American Inglewood; 1943): 14,800
B-25 (North American Inglewood; 1944): 10,700
C-46 (Curtiss Buffalo; 1943): 113,000
C-46 (Curtiss Buffalo; 1944): 49,500
C-54 (Douglas Santa Monica; 1943): 142,100
C-54 (Douglas Santa Monica; 1944): 62,600
P-38 (Lockheed Burbank; 1943): 14,800
P-38 (Lockheed Burbank; 1944): 9,600
P-47 (Republic Farmingale; 1943): 9,600
P-47 (Republic Farmingale; 1943): 9,100
Source (along with a bunch of other useful production data)

His main page also has a bunch of other useful data for production. For comparison, this page also has some mentions of productivity through the Industrial revolution, and this page mentions the man-hours to produce a car in 2008- 13.57 to 35.1.

There is also a bunch of other unconfirmed data on man-hours to produce an aircraft on this forum page.

Hopefully this data will let me get a better idea of how many man-hours the fighter can be expected to require, and how much those man-hour requirements can be reduced with certain design choices.

It should be in there somewhere (some planes are in there multiple times for different sources, factories, variants, or dates of production)

 

[tomo pauk]

The 12Z and VK107 still got up to 1,800 HP, and that was enough to last the French and Soviets to the jet age, so at least it was good enough for them.

Thanks for the exhaustive list of aircraft prices.
For the HS12Y - the VK-107 shared about nothing with it. Crankcase, crankshaft, blocks, pistons, heads, valve gear, air & mixture distribution, supercharger, reduction gear, carburetor(s) - everything was new. It took Soviets more than 5 years of hurried war-time design to have VK-107 run reliable just when ww2 ended; the ww2 era VK-107s were a hot mess with 25 hours between overhaul.
As for the 12Z making 1800 HP, seems this is way too optimistic. See posts by 'Bretoal' here; the Yugo S-49 fighters' HS-12Z-17s were under 1500 HP.

 

[AJE]

For the HS12Y - the VK-107 shared about nothing with it. Crankcase, crankshaft, blocks, pistons, heads, valve gear, air & mixture distribution, supercharger, reduction gear, carburetor(s) - everything was new.

But still developed from the previous engines, so it was a member of the Hispano-Suiza 12 family of engines.