Sten SMG aircraft: productionized aircraft part 2, the what if

[tomo pauk]

This kind of points out the problem with the Sten gun school of aircraft design.
If you want to use the same power plant and armament of the standard/first line fighters you have already spent 46.6% of the total cost.
If you can reduce the cost of the airframe by 20% your Sten fighter will cost about 89.49% as much as the standard fighter. Is that "savings" worth it? as in pay for the new tooling, duplication of supply, etc.

Sten was not just about price being low (that certainly helped), but also about the ability to make them in big quantities for a major war that was to swallow man and material alike. Eg. neither of the 3 Italian fighter producers, whose series-produced fighters were worth talking about (Fiat, Macchi, Regianne), was not offering a fast-to-manufacture A/C.
Eg. see here for the MC.202, particularly the wings - each rib was a built-up piece, making the aircraft taking much more manhours than what would a wing that had stamped 1-piece ribs, as in case of Bf 109 for example.

High manhour cost was noted by the Germans when they were testing the '5 series' fighters, looking to perhaps make the best of them in Germany.

Now if you can use a cheaper engine things get a bit more attractive at first glance but then you are very likely to loose performance. French were pretty good at keeping the speed up. Climb, cockpit view, field performance not so much.
You can get some of the performance back and save money by using less armament.

Money can be saved with less operations and manhours needed to make the A/C in quantities needed.
MS.406 was bad in keeping speed up, and 'good' in keeping the manhour cost high. French aircraft designers didn't have 1000+ HP engines to make their fighter perform, either.
Spitfire, despite it's high manhour cost, was also with bad forward visibility

 

[Shortround6]

Spitfire was a vision champion compered to

A lot of planes may have been able to produced easier with different tool and/or substitutions.

However for stamped ribs you need
1. Stamping presses.
2. Stamping dies.

and how big are the stamping machines?
One piece rib or 2/3 piece?

Unfortunately many companies did not have expensive machine tools or power machinery when starting out and designed things to be built with what they had or anticipated getting soon. An order for 100 planes only allows a budget of so much money for special tools. A contract for 1000 planes can completely pay for more complicated tooling that speeds production. Funding aircraft in dribs and drabs over many small batches insures the highest cost but allows for changing to something else the easiest.

The MC 202 was built to between 1100-1500, accounts differ. However it was built in 11 (?) series ( no idea if they were different contracts) and in 3 factories, one of which built about 100 aircraft. Production was also sometimes divided with MC 200s being continued in production due to a shortage of DB engines. So they really had the worst of several situations.
Spend money and/or move tooling and then not get the DB engines leaving them with nothing for the effort or keep investment to a minimum and make them the old way while waiting for engines to dribble in.

 

[z42]

Sten was not just about price being low (that certainly helped), but also about the ability to make them in big quantities for a major war that was to swallow man and material alike.

So with this definition the Hurricane would be a good example of a Sten fighter. Cheaper and faster to build than the Spit, yet still good enough to be useful as a fighter early in the war.

 

[tomo pauk]

1-engined Schnellbomber probably qualifies as as a Sten among the bombers.
For the Italians - they were on the right track with the Ca.335 and 355 types (yes, no possibility of mixing these up, not at all ) - aircraft sized between Spitfire and Hurricane, reasonably streamlined, with V12 engine in the nose.
Shortcomings - as usual with the Italian good stuff, they were too late, with Ca.335 also having the bad luck that it was not available for their air force for testing and further improvement since the only example was captured in Belgium by the Germans, who refused to have the Italians reposes it. Bombload was also modest, 100 kg on the prototype; the 355 was to carry up to 400 kg (~900 lb) bomb

Had the Italians had desire to make it at home - Sabca in Belguim was to produce the 335 as S.47 - they could've installed the Asso IX, or the L.121, and have a bomber as fast as MC.200, or, more importantly, as fast as the Hurricane. Let alone the P.24, Fulmar or Gladiator; up the bomb load as it was possible to do.
Another appeal for the Italians, and in line with the Sten principle, is that such a bomber would've been far easier to make than a host of small twin-engined bombers Italians/Caproni have had penchant for.

Granted, by some time 1942, a much better V12 would've been needed, than it were the legacy Italian engines. meaning that Germans, British, or even the Soviets or Americans were in an even better position to make this work, in any ww2 year we discuss this. Even the French.
Both Germans and British can do this in 1937-38; Americans can do it with turbo 'support' even earlier.

 

[special ed]

Umm... like the He 70?

 

[tomo pauk]

Umm... like the He 70?

He 70 strikes me as too big to function as an 1-engined Schnellbomber (and the 118, that was of similar shape and size) - after all, wing size was that of the Bf 110, or 60-100 % greater than the 1-engined fighters of the day. We'd get sorta German Battle with the DB 601 in the nose? We can see that already the Henley is ~40 mph faster than the Battle, on same engine, but smaller.

Japanese have gotten the size and shape right with the D4Y*, the bomber being as fast as the current Zero or Ki-43 and very long ranged. Size-wise it was sorta Spitfire with fatter fuselage, the bomb bay located behind the cooling system.
The 1st version was 30-35 mph faster than the Henley, despite a bit lower engine power at altitude; it was also faster than the Hurricane of Bf 110C.

*what they didn't get right was opting for fuel tanks without self-sealing, and meager protection for the crew (situation like in the West before 1939-ish); also the bomber was initially not very good as a dive bomber operating from carriers (neither is much of concern for Europe, even for Germany if they opt to dispense with dive bomber everything)

 

[tomo pauk]

A generic (= anyone could've did it, even a few years before ww2) fast-ish bomber: your current V12, beard radiator with a decent bomb behind it. Nose is nicked from P-40, rest from Ca 335.

 

[Bretoal2]

A generic (= anyone could've did it, even a few years before ww2) fast-ish bomber: your current V12, beard radiator with a decent bomb behind it. Nose is nicked from P-40, rest from Ca 335.

View attachment 742044

Fairey Battle ?

 

[tomo pauk]

Fairey Battle ?

Batle was too big - talk Bf 110 with just one engine in the nose instead of two on the wings.

 

[Shortround6]

Batle was too big - talk Bf 110 with just one engine in the nose instead of two on the wings.

The curse of trying to get a heavy load out of a small field using a crappy propeller

 

[tomo pauk]

The curse of trying to get a heavy load out of a small field using a crappy propeller

I don't think that anyone was using fixed pitch prop on their bombers by late 1930s.

 

[Shortround6]

I don't think that anyone was using fixed pitch prop on their bombers by late 1930s.

You are quite correct.
The British thought that a 2 pitch prop was a gift from god

But you may want to check on some of the 2nd line aircraft in some countries.

 

[tomo pauk]

An interesting claim from a book (Caccia assalto 2) that deals with Italian ww2 aircraft: that one MC.202 required 21000 manhours and Lire 514000, while the SAI 403 was supposed to cost Lire 96000, and required 6000 manhours.
FWIW

 

[z42]

An interesting claim from a book (Caccia assalto 2) that deals with Italian ww2 aircraft: that one MC.202 required 21000 manhours and Lire 514000, while the SAI 403 was supposed to cost Lire 96000, and required 6000 manhours.
FWIW

Wiki says only a single prototype of the SAI 403 was ever made, so hard to see what the relationship is between the above numbers and the actually realized numbers had the aircraft been mass produced.

 

[tomo pauk]

Wiki says only a single prototype of the SAI 403 was ever made, so hard to see what the relationship is between the above numbers and the actually realized numbers had the aircraft been mass produced.

Hence the "FWIW"

 

[Shortround6]

Wiki says only a single prototype of the SAI 403 was ever made, so hard to see what the relationship is between the above numbers and the actually realized numbers had the aircraft been mass produced.

Well, the SAI 403 wasn't that different than the SAI 207 which was based on the SAI 7 and they built 10-12 of each of those.

Not mass production but at least some idea of what it took to screw-glue one together.
Of course when you are trying to get the contract the labor bill is always a little low.

 

[GrauGeist]

That canopy, though...

 

[Shortround6]

That canopy, though...

Also shows what happens when you think that you can just stick a couple of guns in a racing plane and get an instant fighter

 

[SaparotRob]

That canopy, though...

Looks better than the Skua's.

 

[tomo pauk]

A more neutral Yugoslavia - make the sibling of the F-5 by making a deal with Northrop, instead of making a bad copy of the Jaguar with Romanians. Viper jet engines should've been a good fit, it even uses a bit less fuel than the J-85.
Both West and East agree that F-5 was straightforward to make and use, Yugoslavs get a supersonic aircraft unlike what Orao was, while there is no drop in ordnance capacity vs. Orao.

Romanians can 'retaliate', and make a MiG-21 spin-off with a better wing (at least what the J-7 had) and side air intakes, sorta the JL-9.