Ideal fighter for VVS, 1941-42

[davebender]

You want a high - low mix. Lot's of inexpensive but capable short range fighter aircraft for defensive purposes and to serve as escort for CAS missions up to about 75 miles behind enemy lines. Plus a smaller number of more expensive fighter aircraft that have the combat radius for escorting bombers. The YaK was the VVS low cost fighter aircraft and it should have production priority. There's no point talking about strategic bombing if you cannot secure your own airspace.

 

[Shortround6]

There wasn't a Hi-Lo mix in WW II as far as money went. The Russians had one engine available be for fighters until the M-82 came along. they had one 20mm cannon and one 12.7 machine-gun. the plane either had a radio or it didn't. Short range planes don't need radios?
What do you leave out of your "Lo" mix fighter? One or two fuel tanks and a dozen sq ft of wing? That won't change the price by more than a few percent. All the expensive stuff--- engine, propeller, retracting gear, brakes, instruments, radios, oxygen systems and guns cost the same regardless of the size of the airframe.

Modern air forces with a Hi-Lo system often use different engines ( or a single instead of a twin) , different radars and electronic suites ( a major expense) in addition to different file capacities come up with vastly different sized aircraft.

Using more different types of airframes than you have to results in higher spares and logistics costs. A hidden cost in the Hi-Lo mix that is often over looked.

 

[tomo pauk]

The inability to except a prop hub gun is also a property of the radial engines, as well as the Western in-lines, so why not put the 2 Shvaks under cowling, maybe aside the crankcase? That equals the punch of the La fighters prior late 1944/early 1945. The radials were also large heavy.
The single speed engine is good for 1250 HP at 16100 ft - a tad better than Merlin 45, while better than V-1710, even with 9,60:1 supercharger. It's significantly heavier than those two, though. The lighter weapon ammo package would even out the things somewhat. No Soviet plane carried better punch than 2 Shvaks until late 1942, until the advent of the heavy weight (for Soviet standards) the Lagg-3-37.
All of the fuel can go to the wings, IIRC that's how the MiGs and La(GG)s were practicing anyway.

The change of the supercharger ratios for a FTH reduction to 4km (~13000 ft) should indeed release some power down low, but the 5 km of altitude is hardly that punishing for such a set-up.

 

[davebender]

In addition to being a fire hazard adding a lot of weight to the wings is bad for maneuverability. Not a big deal for bombers but I wouldn't put a fighter aircraft main fuel tank in the wings except as a last resort.

 

[Shortround6]

About 400-500lbs heavier, the extra length compared to the radial may mean the center of gravity of the engine is further forward than the slightly heavier radial. The guns have to be behind the engine ( barrels can be along side) as you have to get the ammo in and out of the receiver.
At almost a 50% increase in weight over the M-105 this engine Poses some real challenges to a fighter designer.
The Mig had some serious CG issues which is why it was never upgraded. A new design may get around that but at the cost of a bigger airframe to begin with which cuts into the performance.
Russians tried single 12.7 under each wing but didn't like the performance penalty, reportedly the up-gunned fighters
could not maintain formation with the regular fighters.

 

[tomo pauk]

The M-105 is light, but the power is on the weak side. The radials are in the same category, plus the drag penalty*. The AM-35 is big heavy, while offering more power, esp. at higher altitudes. The weight power can be compared with DB-601/Merlin/V-1710 - the power to weight ratio would be maybe at 90-95% of these, in 1941?
What could M-105 offer, for the 1941 plane? The performance comparable with Spits 109s of the BoB era, a resulting plane carrying the 2 Shvaks.
A plane with AM-35 could be something of a 'Soviet Spit V', the engine performance is a tad better than of Merlin 45. The engine is indeed heavier, the armament is lighter. The wing area maybe bigger, not 17,5 m^2, but 20m^2?
The guns' receivers would be located aft the engine, indeed, right by the ammo containers.
Compared with what type of radial is the weight difference 400-500 lbs?

*M-82 being the exception from this sentence. IIRC you have the book about Soviet aircraft engines. How feasible is the M-82 for 1941?

 

[davebender]

1941 is a bad time for Russia to start production of new equipment. Stick with what's available during 1940. Start production of the new equipment during 1942 or 1943 at Tankograd / Aircraftograd.

 

[KiwiBiggles]

In addition to being a fire hazard adding a lot of weight to the wings is bad for maneuverability. Not a big deal for bombers but I wouldn't put a fighter aircraft main fuel tank in the wings except as a last resort.

The thick wings of the Typhoon were partly the result of an Air Ministry directive that in fighters the main fuel tanks should be in the wings. I believe this was mainly to reduce the fire danger for the pilot. When the Tempest was developed from the Typhoon, its thinner wings couldn't hold as much fuel and so a fuselage tank was reintroduced; hence the Tempest's longer fuselage.

The point is, the Typhoon was not noted for its vulnerability or lack of maneuverability. In fact, I would expect that, for an air-to-air fighter, fuel tanks in the wing would be a smaller and therefore less vulnerable target for the usual attacks from behind or ahead. Wing tanks would only really be at risk from rare high-deflection shots, although I admit that they would be more vulnerable to ground fire.

As for maneuverability, wing tanks would only ever be close in to the fuselage. Any wing space outboard of the propeller arc is too valuable as a location for guns. So the increase in the lateral second moment of mass was fairly small. And the benefits of having your variable mass close to the aerodynamic center are great.

 

[wuzak]

The AM-35 is big heavy, while offering more power, esp. at higher altitudes. The weight power can be compared with DB-601/Merlin/V-1710 - the power to weight ratio would be maybe at 90-95% of these, in 1941?

A plane with AM-35 could be something of a 'Soviet Spit V', the engine performance is a tad better than of Merlin 45. The engine is indeed heavier, the armament is lighter.

Lumsden has the Merlin 45 at 1200hp @ 2850rpm, +9psi boost @16,000ft as normal/maximim climb power. Maximum/Emergency power is listed as 1230hp @ 3000rpm, +12psi boost @ 18,000ft. At a weight of 1385lb.

T/O power is weaker for the Merlin 45 than the AM-35, being rated at 1230hp @ 3000rpm, +12psi boost. All ratings 100 octane fuel.

Wiki has the AM-35 weighing 1830lb.

The Griffon II entered production in 1942, weighing 1790lb and giving 1720hp for takeoff, 1735hp @ 1000ft and 1495hp @ 14,500ft. (Lumsden is confusing for this entry as it gives the same ratings for both normal/continuous climb and maximum/emergency).

 

[claidemore]

I-28 with M-88 engine. 2 x 12.7 BS and 1 x 20mm ShVak, wood construction. Used an engine which was pretty much wasted on ineffective bombers (R10 and Su2).
edit: not the Yakovlev I-28/Yak 5, the Yatsenko I-28.

 

[tomo pauk]

The fighter with an M-88 could be the 'Soviet P-66', with 2 cannons instead of 6 MGs. The plane should be tailored with M-82 in mind, so the modernized type could be built when M-82 production ramps up.

 

[Glider]

Ideal fighters for the VVS in 1941/2 a Fw190

 

[davebender]

1941 versions of the Fw-190 weren't all that capable or reliable. Why would you want to stick the VVS with a Fw-190A1 or Fw-190A2?

 

[Altea]

If you go with the smaller airframe you are limiting the development potential or suitability for other roles. Internal fuel needs to be close to the CG. Usually either in front of the pilot, under the pilot or in the wing roots. With small wings a larger percentage of the wing root is taken up by landing gear. Putting fuel tank/s under the pilot means a taller/fatter fuselage. You may not have room for the fuel you need if the airframe is too small.
Please remember that drop tanks are for getting to the fight. Internal fuel is for fighting and getting home. Range problems cannot be waved away by using drop tanks.
Higher wing loading (smaller wing) means more difficulties in operating from forward fields. Or for trying for the high altitude role.
Small airframes make mounting heavier armament more of a problem. Is sticking with one 20mm and two 7.62mm guns what you really want to do?

Great range, great firepower are good thinks. OK
Now that said you have to define your priority, and it is to be able to outfight your opponents, such as the Bf-109E, and 109F with the best chances. A real challenge since you have less powerfull engines than DB, and no light alloys.

I agree with potential or suitability for other roles about big airframes of Hurricane, P-40, Mustang mk 1. But remember that none of them was able to deal with last E-7 and "Freidriches". Fortunatly british had Spitfires and soviets Yak-1.

The VG-33 (558 km/h) was not outperformed by the 109E, a spectacular performance if you consider that it used only a 860 hp engine against 1100 or 1175 PS ones.
Soviets had to deal with the same problem, in 41-42, the M-82 excepted.

So potential developpement reminds a luxury in 41/42 for american 2000-2200HP motorised planes.

Regards

 

[Altea]

I think it was a dedicated site to planes, not to humour!


What a piece of scrap: it was 520 lb heavier than the M-105, and only 44 lb lighter than the 1665 HP M-38!

And so the story ends? NO! It had about 35 statistical hours of life expectancy (TBO).
So in order to give a chance to a soviet pilot to deal with a german "rookie" (350 flying hours) you would need to worn out 10 MiG's in order to fight on the 11th one !!!

 

[Shortround6]

Great range, great firepower are good thinks. OK
Now that said you have to define your priority, and it is to be able to outfight your opponents, such as the Bf-109E, and 109F with the best chances. A real challenge since you have less powerfull engines than DB, and no light alloys.

I agree with potential or suitability for other roles about big airframes of Hurricane, P-40, Mustang mk 1. But remember that none of them was able to deal with last E-7 and "Freidriches". Fortunatly british had Spitfires and soviets Yak-1.

The VG-33 (558 km/h) was not outperformed by the 109E, a spectacular performance if you consider that it used only a 860 hp engine against 1100 or 1175 PS ones.

The VG-33 is rather unproven and some of it's numbers look a little suspect. It is also a great example of what I mean by a small airframe compared to a "bigger" airframe and I am NOT referring to the Hurricane, P-40, Mustang mk 1 class of planes.

The VG-33 has wing area 81% of a YAK-1 and claimed empty weight of 77% of the YAK-1. gross weights are closer but still the VG-33 is supposed to be only 90.6% as heavy using the same basic engine. Now there may be a difference in the way the empty weights were figured ( empty and empty equipped ?) but there is a very good chance that the VG-33 did not have armor or protected fuel tanks. It's armament also weighed more, granted a Russian version could use the lighter Russian guns but the Russian engine was heavier.
Development does not need to mean a pair of 1000lb bombs or a new engine with 2000hp.

Try hanging a pair of 220lb (100kg) bombs under the VG-33 and see what you get, a wing loading of 42.7lb/sq/ft. You would have to load a YAK-1 to 7900lbs to get a wing loading that high and the Mustang can go to 9950lbs. Now how suitable is the VG-33 for use from typical Russian front line airfields with it's higher take-off and landing speeds? Good thing it is fast because even without bombs and with some fuel burned off you are going to have a wing loading of 37-38lb/sq/ft which means not so good in the turns.

Weights I used were from Virtual Aircraft Museum site and may be a bit off but I think they give the idea. Going much smaller than the 109 or YAK or LAGG means having difficulty even reaching their levels at a later date.

 

[tomo pauk]

Hi, SR6, a question (IIRC you have some book(s) about Soviet engines):
Was the M-82 production in 1941 big enough to support a major-scale production of a plane that would feature it?

I think it was a dedicated site to planes, not to humour!


What a piece of scrap: it was 520 lb heavier than the M-105, and only 44 lb lighter than the 1665 HP M-38!

And so the story ends? NO! It had about 35 statistical hours of life expectancy (TBO).
So in order to give a chance to a soviet pilot to deal with a german "rookie" (350 flying hours) you would need to worn out 10 MiG's in order to fight on the 11th one !!!

In what altitude the AM-38 achieved that power? IIRC it was a low-alt development of the AM-35. Maybe it was unfortunate for Soviets that a 'mid-alt' version of either the -35 or -38 was not produced; the AM-37, an alternative, being prone to overheating.

 

[tomo pauk]

double

 

[Glider]

1941 versions of the Fw-190 weren't all that capable or reliable. Why would you want to stick the VVS with a Fw-190A1 or Fw-190A2?

With 400 mph and four cannon, yes, I would take it in any 1941 airforce, Russian, British, Japanese or American

 

[Shortround6]

Hi, SR6, a question (IIRC you have some book(s) about Soviet engines):
Was the M-82 production in 1941 big enough to support a major-scale production of a plane that would feature it?

I don't believe so. It past it's second set of state tests on the 22nd May of 1941 although a decree to start production was issued on May 13. It was first built at factory No. 19 in Moscow with factory No. 29 in Omsk joining in 1942. About 24,000 engines were built during the war. The Major users were the LA-5 and LA-7, the Tu-2 and a few PE-8s. I think you can figure the introduction of the LA-5 as when it became available in more than handfuls.

In what altitude the AM-38 achieved that power? IIRC it was a low-alt development of the AM-35. Maybe it was unfortunate for Soviets that a 'mid-alt' version of either the -35 or -38 was not produced; the AM-37, an alternative, being prone to overheating.

There were 8 versions of the M-35(AM-35) but putting aside the turbo-charged versions, fuel injected versions and the boat engine there were was only the AM-35A in real production, about 4,650 engines were built include a few late ones with AM-38F parts. It was followed by the AM-37 with increased supercharging and an intercooler (aftercooler?), there were 5 versions at least planned but only 29 engines total were built. The AM-38 was built in 2 versions, the AM-38A and the AM-38F with over 43,000 engines being built. Further developments include the AM-39, AM-40, AM-41, AM-42, AM-43, AM-44, AM-45, AM-46 and AM-47. The later engines being primarily post war.

Some Western books give the altitude ratings as 1200hp at 6000meters Military rating for the AM-35A and 1150hp at 7000meters Normal rating which doesn't sound quite right with the AM-38A giving 1550hp at 2000meters Military and 1410hp at 3000meters normal. The AM-38F was listed at the same power at altitude but had an extra 100hp for take-off.

The translated Russian book does not give altitudes in most cases.