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

But still developed from the previous engines, so it was a member of the Hispano-Suiza 12 family of engines.
Not a single bit from the HS 12 familiy of engines fit on a VK-107.
Same as not a single bolt from the Buzzard will be able to fit on a Griffon for the Griffon to work as it should.

We can debate the family issues all day, the HS 12Y was still a worse engine than the DB 601 or Merlin, and by a good margin. Unfortunately, the best French engine was that HS 12Y.
 
no love for the Vickers Venom (probably in place of the Gladiator)

?
It's hard to figure out which engine would fit best.

It's a lot easier to play with an idea that has an otl engine. The Venom's engine was thrown out at prototype stage. None of the other Bristol radials fit nicely. The Mercury is more than half again the size.

Also of course Vickers was a bit overloaded at this time so capacity probably wasn't available.

Production could of course be licensed out but Vickers tended to make bad partners when it came to licensing out their aircraft designs.
 
Not a single bit from the HS 12 familiy of engines fit on a VK-107.
Same as not a single bolt from the Buzzard will be able to fit on a Griffon for the Griffon to work as it should.

We can debate the family issues all day, the HS 12Y was still a worse engine than the DB 601 or Merlin, and by a good margin. Unfortunately, the best French engine was that HS 12Y.
Fitting parts doesn't matter, as long as the engine was developed by modifying the previous engine and not designing it from scratch, it's a member of the family, and represents one potential of the basic design of that engine family. Besides, the HS 12Y wasn't worse than the DB 601- it didn't have dry sleeves or a combination of gallery oil feed and inverted layout, so it actually worked reliably in exchange for its lower power. It may have been worse than a Merlin or Jumo 210/211, but it could match a DB 601 overall.
 
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Idle question but the Germans built over 600 Bf-109D. What happened to them after being phased out of service? Is there a reason they could not be handed over to their minor allies when they were still flying P.24s and biplanes?
 
The Gloster F5/34 might fill the OP's criteria for a light weight fighter though in using the Mercury engine, in fighter terms a second line engine, it does fulfil that requirement. Though the AM and RAF would be loath to part with any Mercuries as they were being reserved for the Blenheim at the time.
An alternative aircraft OTL is the Martin Baker MB2 specifically designed for ease of construction and field maintenance it's Napier Dagger gave a peak out put of 820 Hp. Change this for a RR. Kestrel XXX which could get 750Hp or more and carryout the proposed development of the MB2 to have 20mm cannons and retractable under carriage and you could well have a 300mph second string cannon armed fighter by the end of 1938 that could be massed produced. If the Dagger could be got to work reliably and not deafen all and sundry within half a mile then sticking with that power plant might work as well.
 
From a long set of PMs I made on an ideal WWII fighter:

Spitfire Mk 1A January 1940: 15,000
Spitfire Mk V 1942: 13,000
Hurricane January 1940: 10,300
thanks, this is fascinating. Spitfire goes from 145% of 1940 hurricane to 126% of 1940 hurricane in ~2 years while presumably also gaining more complexity in terms of e.g. tank installation. Also shows the difference between designed for production machines in modern industry (bf109, P-51) vs Italian arts and crafts approach, with UK somewhere in between.
But still developed from the previous engines, so it was a member of the Hispano-Suiza 12 family of engines.
But on that basis one might as well say that the Mistral Major was successfully stretched to 1600hp and should have been a fully competitive war-winning engine for France. However SNECMA getting the 14R to the same level in 1949 that Merlin etc had in 1942 isn‘t much use to anyone, so it’s more informative and succinct to say - all the french engines were poor during the rearmament period.

Again, in a lineup of Merlin, DB201, JM210, V-1710, 12Y and even the Kestrel then picking out the 12Y looks like the booby prize, although it’s still much better than nothing. Also better than a Liberty, BMW VI etc I think?
But with poor power, poor altitude, poor reliability, expensive, it’s not very compelling. By the time all the issues are resolved one could have engineered an early Grifon or DB603 for about the same effort (or an XI-1430, Vulture etc if one is unlucky). However in the sales pitch it looked good, the Hispano legacy was legendary, and by the time the scope of the issues were realised it was too late to start over.
 

Driftless

Donor
Bombers:
Battle January 1940: 24,000
Astonishing list! My first (witless) thought was: how many man-hours did that take to compile the list? ;) :biggrin:

My other tangent thought was the entry for the Battle. By 1940, that was the tail end of the run, so that 24k m/h number seems like a lot of work for limited capability.
 
Idle question but the Germans built over 600 Bf-109D. What happened to them after being phased out of service? Is there a reason they could not be handed over to their minor allies when they were still flying P.24s and biplanes?
I believe the me 109d was convertible to me109e. I believe it may have just needed an engine swap and some small modification.

At any rate the Germans would have seen the me 109ds as more valuable being stripped for parts to support the me 109es rather than shipping them off to allies.
 
But on that basis one might as well say that the Mistral Major was successfully stretched to 1600hp and should have been a fully competitive war-winning engine for France. However SNECMA getting the 14R to the same level in 1949 that Merlin etc had in 1942 isn‘t much use to anyone, so it’s more informative and succinct to say - all the french engines were poor during the rearmament period.

Again, in a lineup of Merlin, DB201, JM210, V-1710, 12Y and even the Kestrel then picking out the 12Y looks like the booby prize, although it’s still much better than nothing. Also better than a Liberty, BMW VI etc I think?
But with poor power, poor altitude, poor reliability, expensive, it’s not very compelling. By the time all the issues are resolved one could have engineered an early Grifon or DB603 for about the same effort (or an XI-1430, Vulture etc if one is unlucky). However in the sales pitch it looked good, the Hispano legacy was legendary, and by the time the scope of the issues were realised it was too late to start over.
If you're evaluating the engine as it existed and not whether it was worth developing further, then yes, the existing HS 12Y was largely inferior to the Merlin, Jumo 210, and V-1710 families. It was certainly superior to the old WWI-era engines with individual cylinders (Liberty, BMW III, Napier Lion families), and still superior to early monoblock wet-sleeve engines (Curtiss D-12, Kestrel families). Against a DB 600 series engine, it was a better design so more reliable (DB never fixed the problems with the engine), though was more lightly built so less powerful in the HS 12Y variant, so it was probably a match for a DB 600 or 601, though inferior to a later 601, or any 605 or 603.

Against the Mikulin AM-34 family, I don't know, it was maybe equal to an M-34RNA. I wonder if the Soviets would allow license production of the AM-34 to countries during this period.
 
Besides, the HS 12Y wasn't worse than the DB 601- it didn't have dry sleeves or a combination of gallery oil feed and inverted layout, so it actually worked reliably in exchange for its lower power. It may have been worse than a Merlin or Jumo 210/211, but it could match a DB 601 overall.
Jumo 210 was perhaps 3rd league engine, even the Kestrel or Mercury were better. A V12 of 19L displacement will not be going very far.
Jumo 211 was a 35L engine, it was much easier to extract more power there. Having a 2-speed drive for the S/C meant that it was not scarifying high altitude power to gain low-altitude power and vice-versa.
The DB 601 was better still - 1100 to 1100 HP at low altitudes, 1020 HP at 4-4.5 km. All by winter of 1938/39. A variable-speed supercharger covered well altitudes between SL and higher ones.
All of those worked reliably while offering better power than HS 12Ys.
There was no 2-speed nor variable-speed drive for S/C on the HS 12Y, and the best in-service version - HS-12Y-45 - was one year late vs. DB 601A. The -45 have had a much improved S/C, with variable intake vanes that helped lowering the losses at lower altitudes. It was still halfway in power vs. altitude between the legacy HS 12Ys - like the ones installed on MS-406 - and DB 601A.
(those installed on MS-406 or on VG-33 were making the power at 4 km about as good as the humble Mercury on the Gladiator or on the Blenheim)
Whether a V12 was inverted or not was not a mark of good or bad engine.
 
Again, in a lineup of Merlin, DB201, JM210, V-1710, 12Y and even the Kestrel then picking out the 12Y looks like the booby prize, although it’s still much better than nothing. Also better than a Liberty, BMW VI etc I think?
But with poor power, poor altitude, poor reliability, expensive, it’s not very compelling. By the time all the issues are resolved one could have engineered an early Grifon or DB603 for about the same effort (or an XI-1430, Vulture etc if one is unlucky). However in the sales pitch it looked good, the Hispano legacy was legendary, and by the time the scope of the issues were realised it was too late to start over.

DB is probably the 601? Jumo - we'd want the 211? Problem with both of them is availability for anyone that is not Germany before 1940, so it is questionable for a 3rd country to bet the house on those.
The 210 was small and of low power, but it was doing well in small fighters like the Bf 109 or He 112.
Kestrel is very interesting, although the HS 12Y of the day will do better power at lower altitudes, and offers the prop-gun facility; Kestrel is physically much smaller, though.
Both Kestrel and Jumo 210 on something like the diminutive SAI.207 would've been interesting, seems like it was making 575 km/h on 750 HP.
Liberty and BMW VI don't matter much, neither is outfitted with supercharger as-is. Ditto for the Fiat A.30.
V-1710 on something small might bring a winner, however it was not available for anyone before France folded, and even then just for the countries US allowed the export (UK, China).

HS 12Y was a decent engine, however being 3rd or 4th best is not much of an accomplishment.
 
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.

I see where you're going but as soon as a single player in that environment purchases an air dominance fighter, it negates the other more affordable types that surrounding nations may have purchased as well. Just as an example if Brazil bought two squadrons of Gladiators, then they would suffice only until Argentina bought a squadron of Me-109e's. As soon as that happens the value of the theoretical minimum fighter is gone. The concept arguably only works as long as everyone else in the theater agrees to the same limitation.
 
When it comes to a minimum fighter there's a key question of what we do we want.

In this thread we seem to be looking at the best fighter we can build without using a top of the line engine. This could be for cost reasons or because we can't access the top of the line engine.

I'd like to look at what we need from a performance idea.

From a performance perspective a minimum fighter during ww2 is one that is competent at fulfilling the roles of a fighter in the absence of front line opposition.

IIRC there was only one squadron of Gladiators operating as fighters during the battle of britain. They were in northern Scotland. Out of the range of ME 109s. The threat was unescorted bombers or ME 110s.

In the Brazil Argentina example this is a very valid role as a lot of Brazil and Argentina were out of range of opposition air bases for fighters.

Many fighters suggested in this thread can fulfill this role.

The second performance goal of a minimum fighter is top cover. That is operating as an escort fighter when the enemy does not have radar. This means that intercepting fighters are almost always climbing, reducing their effectiveness significantly as opposed to a fighter at altitude. It also includes operating defensively against bombers and fighter escorts with a radar advantage (where you can reliably be at altitude before attackers).

This performance goal is one that very few fighters discussed here can fulfill.

It's an interesting distinction.
 

Driftless

Donor
The second performance goal of a minimum fighter is top cover. That is operating as an escort fighter when the enemy does not have radar. This means that intercepting fighters are almost always climbing, reducing their effectiveness significantly as opposed to a fighter at altitude. It also includes operating defensively against bombers and fighter escorts with a radar advantage (where you can reliably be at altitude before attackers).

This performance goal is one that very few fighters discussed here can fulfill.

It's an interesting distinction.

Could this role be filled with a plane of lesser performance, but with longer range/loiter capability - as a make-do-with-what-we've-got?
 
DB is probably the 601? Jumo - we'd want the 211?

HS 12Y was a decent engine, however being 3rd or 4th best is not much of an accomplishment.
Sorry, I’m unbelievably incompetent at typing on a tablet. Yes, DB601 but even the Luftwaffe couldn’t get enough of those. Not sure about availability of the Jumo engines but I assume easier to get the 210 than 211 which in turn easier than DB601 - although all may have been unavailable for export? V-1710 is probably more a concept than a reality in rearmament period with only a few dozen examples available in 1939. So all those are more like “here’s what you could have won” I suppose. Then there are ramp head merlins, Kestrels, 12Ys of which one is decent, one is interesting and the last somewhat sub-par IMO. Then all the round engines.

HS12Y seems to have been OK so long as it was not required to make maximum possible power, but unfortunately that is exactly what everyone wants from a military engine. Especially if the neighbours are hostile and have very good engines available to them. The reliability problems could probably have been worked around in the same way the Russians worked around their engine issues if the AdA had plentiful spare aircraft, engines and parts but unfortunately they did not. Failing that it would need a very efficient airframe to avoid demanding too much power.

Which brings me back back to the 109. Cheap, small, probably effective even with limited power, it or something very like it is very attractive despite its many well known flaws and it is a pity that none of the small light weight fighters like Arsenal, Caudron, Ambrosini, XP-77 got the same formula working in a similar timeframe. The LW gets a lot of stick for never moving on from the 109 but if they really were getting them for half or a third the man-hours of a spitfire I can see why they would cling to it.
 
The question defies the military logic of any period. Any fighter plane that isn't near the top of the food chain will get eaten. Of course pilot quality is a huge factor in air combat, but it can only go so far. The Bf-110 was flown by some of the best German pilots, and we saw the results. The F-2F was cannon fodder in the pacific. The P-40 was marginal. Obviously an air force has to balance numbers, and cost, but has to go with the best performance it can reasonable get. The cost of being second best is just too high. During the Cold War the Soviets grudgingly conceded that, by relying much more heavily then the West on SAM systems. In the WWII period that wasn't an option. You ether had first rate fighters, in sufficient numbers, or you conceded air superiority to the enemy.

The the key reason the Axis lost the air war was they lost the numbers game of industrial production. This was the inevitable result of a long war, against larger industrial powers. However they also lost the war of pilot training, which caused a serious erosion of combat capabilities particularly with Japan. German aircraft tech was competitive to the end, but fell behind in some key areas, but the situation would only have been worse with less capably fighters then the Bf-109, or FW-190. If the Allies had a cheap fighter doctrine their losses would've been even more severe, in a war of severe losses.

As for smaller powers they always have to get what they can afford on their more limited budgets, but even they will get the top of the line when they can. Today they can buy cheap Russian, or Chinese fighters, or F-35's. It's where their priorities, and political alignment take them.
 
Yes, DB601 but even the Luftwaffe couldn’t get enough of those. Not sure about availability of the Jumo engines but I assume easier to get the 210 than 211 which in turn easier than DB601 - although all may have been unavailable for export? V-1710 is probably more a concept than a reality in rearmament period with only a few dozen examples available in 1939. So all those are more like “here’s what you could have won” I suppose. Then there are ramp head merlins, Kestrels, 12Ys of which one is decent, one is interesting and the last somewhat sub-par IMO.
Jumo 210 was probably easiest to get of German V12 engines. The 211 was a bit later than the DB 601A by a few months; indeed nobody gets those unless it is in bed with Nazi Germany, or nazi Germany want's them there.
The HS 12Y was no worse than Kestrel, ramp-head Merlins were not available to anyone? Seems like only Yugoslavia and Belgium gotten the Merlin II or/and III. France told Yugoslavia to shop elsewhere by the late 1930s, so they bought the Avia-produced 12Ys for the IK-3 and Italian radials for the proposed Orkan bomber after the Do-17s gotten the G&R radials.

All in all, for a 'third' country in second half of 1930s, the RR Kestrel was probably the most sensible V12 engine on the market - available, of modest size and weight, and with decent power at altitude.

HS12Y seems to have been OK so long as it was not required to make maximum possible power, but unfortunately that is exactly what everyone wants from a military engine. Especially if the neighbours are hostile and have very good engines available to them. The reliability problems could probably have been worked around in the same way the Russians worked around their engine issues if the AdA had plentiful spare aircraft, engines and parts but unfortunately they did not. Failing that it would need a very efficient airframe to avoid demanding too much power.

Agreed all the way.
Unfortunately, the D.520 was too late, the VG.33 was way too late. The MS.406 was anti-thesis of 'very efficient airframe' in any sense. AdA was in shambles for many years.

Which brings me back back to the 109. Cheap, small, probably effective even with limited power, it or something very like it is very attractive despite its many well known flaws and it is a pity that none of the small light weight fighters like Arsenal, Caudron, Ambrosini, XP-77 got the same formula working in a similar timeframe. The LW gets a lot of stick for never moving on from the 109 but if they really were getting them for half or a third the man-hours of a spitfire I can see why they would cling to it.

109 was an excellent fighter.
Arsenal with VG.33 - too late; it also used the best engine France was making. Caudron - too late, also wrong engine choice (450 HP at 4000m) - too bad they were not using the tiny G&R 14M engine (650 HP at 4000m for 30 minutes). Perhaps this is a cue to just how bad was the French situation when rearmament started? British at least considered 840-1000 HP engines for their 'colonial fighters'.
The XP-77 was even worse than C.714, both on engine choice (Ranger engine took a lot time to became viable) and also in flight characteristics. Ambrosini fighters - again too late.
There was also the MB.700, powered by the G&R 14M engine; too late.

Bf 109 was available in a timely manner, unlike these fighters.
 
The question defies the military logic of any period. Any fighter plane that isn't near the top of the food chain will get eaten. Of course pilot quality is a huge factor in air combat, but it can only go so far. The Bf-110 was flown by some of the best German pilots, and we saw the results. The F-2F was cannon fodder in the pacific. The P-40 was marginal. Obviously an air force has to balance numbers, and cost, but has to go with the best performance it can reasonable get. The cost of being second best is just too high.

We can also point on other stuff that defies logic. Like Bf 110 having any bearing on what the Norwegian, Polish or French pilots will be flying. Or that it took US Navy decades to introduce a monoplane fighter, despite having huge carriers in service.
The case of Bf 110 shows that having the biggest and baddest fighter might not be such a good idea in the 1st place.
 
We can also point on other stuff that defies logic. Like Bf 110 having any bearing on what the Norwegian, Polish or French pilots will be flying. Or that it took US Navy decades to introduce a monoplane fighter, despite having huge carriers in service.
The case of Bf 110 shows that having the biggest and baddest fighter might not be such a good idea in the 1st place.
Ok, what I said about the Bf-110 had nothing to do with what Norwegian, or Polish pilots were flying, because they weren't buying planes from Germany anyway. The Bf-110 was the victim of rapidly changing technology. When it entered service it was faster then just about anything in the air, so it's lack of maneuverability wasn't so critical, but the situation changed by 1940. The French were major aircraft producers themselves, so that's irrelevant to the question. As I said small powers have to buy fighters on the basis of what they can afford, and their political alignment. Smaller powers also have minimal orders, if their not at war, but once their in a war they face the same quality vs quantity questions major air forces face.
 
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