AHC: a 350 mph/560 km/h fighter for 1935

...in production, that is. Historical engines only, aerodynamics of the day, countries can buy engines abroad in friendly countries, or at least those that are neutral for them. Armament not weaker than what OTL fighters had in the time specified.
Some countries will have easier time here than others...
 
109 and Hurricane both flew in 1935 so they would be the easiest to get to 350 Mph, what about building a small early production batch off the drawing board?
 

Driftless

Donor
Hughes H-1 Racer? In it's 1935 base form, it was rated at 352mph; but adding weight for guns, ammo, other military "stuff" is going to reduce that speed. You probably need to goose the P&W R-1535 to pick the speed back up. Jumping up to the R-1830 with it's larger diameter would require redesigning the front end aerodynamic shape.
 
Hughes H-1 Racer? In it's 1935 base form, it was rated at 352mph; but adding weight for guns, ammo, other military "stuff" is going to reduce that speed. You probably need to goose the P&W R-1535 to pick the speed back up. Jumping up to the R-1830 with it's larger diameter would require redesigning the front end aerodynamic shape.

That aircraft is just so beautiful!
 
So we are talking literally World record speed, adding military gear and in production. Not just making a single race plane.
Quite a challenge I'd say.
A push-pull fighter based on DB600 perhaps. Dornier did Work on the design earlier so... Wonder if trial and error could resolve the teething problems though.
 
There were also British push-pull powerplant set-ups, like at Short Singapore (RR Kestrel) and Sarafand (RR Buzzard). DB 600C/D were supposed to be available in 1935, making 910 PS at 4 km.

109 and Hurricane both flew in 1935 so they would be the easiest to get to 350 Mph, what about building a small early production batch off the drawing board?

British comapany to do the high-speed fighter will probably be Supermarine or De Havilland. Engine - either Kestrel or Buzzard; one Buzzard might just make it for this task.
Germany has an advatage that it uses just two LMGs as fighter armament, so less of a drag and weight penalty. British were switching to 4 LMGs with Gladiator, 8 with Hurricane.
 
Easy. Only 350mph?

800px-Macchi-Castoldi_M.C.72_2009-06-06.jpg





For two years, the M.C. 72 suffered from many mechanical defects, as well as the loss of two test pilots who died trying to coax world class speed out of the M.C. 72 (first Monti and then Bellini). The final design of M.C. 72 used contra-rotating propellers powered by a modified FIAT AS.6 supercharged V24 engine generating some 1,900-2,300 kW (2,500-3,100 hp).[3]
FIAT_AS.6_istallato_sull%27idro_MC.72_senza_le_capotes_laterali.jpg

After 35 flights, the engines were overhauled in preparation for a record attempt.[1] The aircraft finally lived up to expectations when it set a new world speed record (over water) on 10 April 1933, with a speed of 682 km/h (423.5 mph). It was piloted by Warrant Officer Francesco Agello (the last qualified test pilot). Not satisfied, development continued as the aircraft's designers thought they could break 700 km/h (434.7 mph) with the M.C. 72. This feat was in fact achieved on 23 October 1934, when Agello piloted the M.C. 72 for an average speed of 709.2 km/h (440.7 mph) over three passes.

Add P-40 Chin radiators to replace surface radiators on the floats, Northrop Gamma landing Gear

north-gamma2g.jpg


and a machine gun in each spat.
Whats that? You want reliable and stable enough not to kill pilots?
Sorry, that wasn't requested.

It's even painted Red, so guaranteed to Go Fasta
 
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Another great topic. Here are the rules I've imposed on myself for a response. Reasonably developed (or developable) engine from a reliable source; airframe from an established manufacturer who had the potential to design it-(in other words no Harry Miller engine in a Wiedell Williams XP-34). Also time for an adequately funded aircraft and engine to experience some development and flight testing before being approved for production by January 1935.

For me , an answer would be a Packard 5A-2500 (1550, to a demonstrated 1800 Hp in 5M variant, which ran in 1930 and was mass produced in WW2. Engine dry weight was 160 pounds more than RR Kestrel.Already supercharged and intercooled.- powering an adequately scaled down Lockheed Altair look-alike, with its retractable landing gear and a metal (Detroit Aircraft) fuselage and cantilever wing. Conventional armament for the time, with two synchronized '30s in nose and two more in wings outboard of LG. With a decent aerodynamicist (possibly Kelly Johnson on summer vacation from U. Mich.) wandering through the project, 350 MPH (and a landplane air speed record) would be a foregone conclusion in 1933 or '34.

Dynasoar
 
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FBKampfer

Banned
Frankly I'm thinking you're going to basically want to take the Do 335, and strip it down, and give a pair of MG's and a 20mm motorcannon.
 
Heres a question. What engine manufactures were designing and producing engines in the 1930s that could utilize high octane fuels? I in his auto biography Jimmy Dolittle describes his frustration when working for a oil company in the 1930s. They refused to sell high octane fuels because there were no engines in the US for sale that use such fuels. The engine builders were uninterested in marketing engines for fuels that were unavailable. If I read the literature correctly fuels ranging from 60 to 70 octane were what was available in the US. Dolittle and others like him hot rodded their aircraft engines and carried cans of additive in the tool box to juice up their commercial fuels.

So, if hot fuels had been available circa 1935 how far can it carry engine performance forward?
 

FBKampfer

Banned
Well really its pretty simple to change the compression ratio. The Germans did it twice I believe, with minimal loss of production.

I think boosting the compression on a DB 600 still leaves it as a DB 600.
 
So, if hot fuels had been available circa 1935 how far can it carry engine performance forward?

Seems Roscoe Turner and his buddies had access to 100 Octane after 1932

He was the 'face' for Gilmore Oil

However, it wasn't till Esso opened a new Plant with an improved alkylation process in 1938 that allowed higher production rates at a lower cost, it became the standard for the USAAC and USN.
 
An increase in compression ratio would improve both power out and specific fuel consumption. Higher step up blower gears mean still more power output and increased altitude performance at the cost of fuel specifics.

Dynasoar
 
Use two engines?

As with the FIAT AS-6, two V-12 connected end to end.
It's one way to avoid crank whip in a single block.

But you were thinking one on each wing, right? extra drag from the installation

Now you could do a Do-335, push and pulling, to avoid the extra drag you get with the extra booms or nacelles
 
Heres a question. What engine manufactures were designing and producing engines in the 1930s that could utilize high octane fuels? I in his auto biography Jimmy Dolittle describes his frustration when working for a oil company in the 1930s. They refused to sell high octane fuels because there were no engines in the US for sale that use such fuels. The engine builders were uninterested in marketing engines for fuels that were unavailable. If I read the literature correctly fuels ranging from 60 to 70 octane were what was available in the US. Dolittle and others like him hot rodded their aircraft engines and carried cans of additive in the tool box to juice up their commercial fuels.

So, if hot fuels had been available circa 1935 how far can it carry engine performance forward?

Hi-oct fuel enable greater boost to be used (I'm asuming the engine has a supercharger - DB 600, HS 12Y, Kestrel, Buzzard, Twin Wasp etc). More boost = more power, gains are in a linear fashion. Shortcoming is that supercharger can provide ever greater boost at ever lower altitudes, so there is no gains above engine's rated altitude for 'normal' boost.

Well really its pretty simple to change the compression ratio. The Germans did it twice I believe, with minimal loss of production.

I think boosting the compression on a DB 600 still leaves it as a DB 600.

Very true.
Increase in compression ratio gives an increase in power in diminishing returns fashion, and increases stress on the engine. Decrease of CR means greater boost can be used, that stacks with increase of boost 'given' by use of hi-oct fuel.
 

Redbeard

Banned
As with the FIAT AS-6, two V-12 connected end to end.
It's one way to avoid crank whip in a single block.

But you were thinking one on each wing, right? extra drag from the installation

Now you could do a Do-335, push and pulling, to avoid the extra drag you get with the extra booms or nacelles

Two engines, one pushing and one pulling, would appear an obvious solution to keep extra drag down following from more engines. But apart from a few floatplanes it is difficult to find operational examples of the principle being applied - was there a backside? Could the turbulence from the front propeller mean that the second propeller is much less effective? Is there a similar effect from contra rotating propellers?

Anyway I'm sure that it would only take minor PoDs to produce an engine with 1000+ HP by 1935 - like a gifted engineer with a few good days and some financial support.
 
In the US if Curtiss had been able to get the USAAC to back off from its 300° operating temperature for the Conqueror maybe somethng could be done there.But I doubt it. I just don't see the US being advanced enough aerodynamically at the time. The Navy is still flying biplanes. The AAC is flying Peashooters with bracing wires for Christ's sake.

Still the idea of Curtiss being able to achieve the required speed, reliability and airframe design is two or three steps too far IMO. That said the Conqueror or the D-12 would of made a hell of a tank engine.
 
Two engines, one pushing and one pulling, would appear an obvious solution to keep extra drag down following from more engines. But apart from a few floatplanes it is difficult to find operational examples of the principle being applied - was there a backside? Could the turbulence from the front propeller mean that the second propeller is much less effective? Is there a similar effect from contra rotating propellers?

IIRC the aircraft that have some distance between the front and back prop didn't suffer any notable drop in reap prop efficiency, like with DO 335. Some countries might not like a tricycle landing gear in mid-1930s, but that should not stop a design and manufacture of it - the layout was used already in ww1.
There was also the Fokker XXIII, a twin-boom A/C, that was supposed to do 326 mph on two 530 HP V12s. The suggested versions with Kestrels, Jumo 210s and HS 12Y didn't materialized, so those should've also been valid proposals if undertaken in time.

Anyway I'm sure that it would only take minor PoDs to produce an engine with 1000+ HP by 1935 - like a gifted engineer with a few good days and some financial support.

There was the RR Buzzard from before 1930, more than 900 HP on 77 oct fuel. The racing spin-off, the RR 'R', was pushed to beyond 2300 HP (using an excotic fuel mix, that included benzole, to allow for greater boost and thus power; also a much bigger S/C was installed to provide that boost).
IMO, a Buzzard running on 87 oct fuel would've been easily above 1000 HP.
 
In the US if Curtiss had been able to get the USAAC to back off from its 300° operating temperature for the Conqueror maybe somethng could be done there.But I doubt it. I just don't see the US being advanced enough aerodynamically at the time. The Navy is still flying biplanes. The AAC is flying Peashooters with bracing wires for Christ's sake.

I Think this is an interesting comment. Why request such an airplane in 1932-33 when 400 km/h would be a killer.
That is However also why it was only achieved later when the target seemed in range.
 
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