Prospective WW2 lightweight multi-role single seat fighter

[BarnOwlLover2]

I got this idea from some discussions I've had elsewhere and something that was brought up in a thread about making a "Spitfire into a baby Tempest". I sort of don't think that the Spitfire IX as built would be 100% suitable for what was mentioned in that thread for a "multi-role" fighter.

Here's what I'm thinking of, and I want those who know more/better than me to chime in. I was thinking of an aircraft powered by a 1700-2000+hp Rolls Royce Merlin or a 2000-2300+hp Rolls Royce Griffon. Both are intended to use two stage superchargers. The intended roles are interceptor, escort fighter and ground attack. This aircraft is intended to be the lightest for the power plants, and suitable armor, self sealing fuel tanks, and range, while being both fast climbing and highly maneuverable.

Basically, the broad specs are a top speed 440-460+mph, a range of 700+ miles on internal fuel (and up to 1500 with drop tanks), a climb rate of 4500+ ft/min., a large wing to minimize wing loading, the ability to carry 1000-2000 lbs of bombs or 8-16 RP-3 rockets or 6-8 HVARs, and the use of Fowler or Fairy-Youngman type flaps for good low speed performance and combat maneuvering.

The aircraft can be made out of wood or aluminum (or a mix of the two), has to be easy to make and maintain, be durable, and maintain performance in concert with those attributes.
Of course, I should note that this was basically what many late war IJA/IJN fighters were aiming for. So maybe use that as a reference if those designers had the Merlin of Griffon available to them.

 

[VictorXL188]

Well first thought to me is something like the Armstrong-Whitworth AW.49

 

[riggerrob]

Who ever said that you NEED twin-booms on a pusher?
Would a slightly asymmetric single tail reduce weight and complexity?

 

[Arjen]

The original baby Tempest - Hawker (Sea) Fury?

 

[riggerrob]

The terms “light-weight” and “multi-role” can be contradictory.
If you design the lightest possible fighter, then you need to delete any equipment needed for ground attack. “Not a pound for air-to-ground.”

OTOH ground attack airplanes need a bunch of bomb-racks, armor, self-sealing fuel tanks, etc. that make it too heavy to be the best possible fighter.

For example, Spitfires were originally designed as light-weight, short-range interceptors - a role that they excelled at during the Battle of Britain.
By 1944 they were pressed into other roles primarily because of shortages of German fighters to tangle with.
With few remaining German defenders, Spitfires risked unemployment during the summer of 1944. So Spitfires were pressed into a geound attack role. Yes, their 2 x 20mm cannons looked as effective as the auto-cannons installed on Typhoons, but Spitfires could not match the bomb-load (barely 1,000 pounds).
Meanwhile, engine advances allowed carrying heavier fuel loads which allowed late-war Spitfires to escort heavy bombers to Berlin. Few Spitfires flew all the way to Berlin as the role was already fulfilled by American-made P-47s and P-51, but Spitfires developed long-range by late war. But again, this was a light-weight airframe that required much additional reinforcing to fill a new role … hardly a light-weight, multi-role airframe from the start.

 

[kaiserd]

No war time Spitfire that saw service in any numbers had 4 cannons (those variants with 4 cannon only really saw service post-war). Those war time Spitfires with cannons had 2 of them plus Machine guns (2 heavy or 4 light). Plus those cannon, as far as I know, were essentially the same make/ variant as the Typhoons (the Tempest and the Fury had a slightly different evolved version of that same cannon). Certainly not radically different cannons.

And while they gained the ability to carry drop tanks and gained some range Spitfires generally did not evolve into long range escorts - that long range role was largely the preserve of the RAF Mustangs that served in surprisingly large numbers, including significant numbers of the later Merlin engined variants. Any Spitfires escorting bombers to Berlin were not flying from the UK mainland. Generally the latest available variant of the Spitfire filled the role of higher altitude fighter top-cover for the fighter-bombers and tactical bombers operating below. As variants of the Spitfire were superseded as the latest and best they were increasingly tasked with the fighter bomber role themselves. This is a bit of a simplification (they were more role dedicated variants and initial production runs of specific fighter variants may not have been equipped or built with the ability to switch roles to fighter-bomber later on).
For example in late 1944 and in 1945 the Spitfire Mark XIV remained a very formidable fighter generally focused on the fighter not fighter bomber role, longer ranged than some earlier variants but certainly not a longer range escort and certainly not remotely with the range of a contemporary Mustang.

And as mentioned by other contributors above the Hawker Fury (destined only to see service in its Sea Fury guise) was the winner of the RAFs war time “light fighter” design competition (a design competition prompted and influenced by the appearance of and reaction to the FW190).

 

[A Tentative Fleet Plan]

No war time Spitfire that saw service in any numbers had 4 cannons (those variants with 4 cannon only really saw service post-war).

The Mk.Vc did see relatively widespread service, indeed any Spitfire with a C or E wing could fitted with four cannon.

 

[kaiserd]

The Mk.Vc did see relatively widespread service, indeed any Spitfire with a C or E wing could fitted with four cannon.

My understanding is that WW2 4 cannon Spitfires were extremely rare (especially in service rather than tests etc.), even if a theoretical option structurally.

Apart from a very small number of rarities 8 light machine guns, then 2 cannon and 4 light machine guns, then 2 cannons and 2 heavy machine guns was how the Spitfires standardised armament evolved during the War with the post war marks finally adopting the 4 cannon armament as standard.

Interesting Imperial War Museum content on this very topic:

View: https://youtu.be/LZ1W8mzooiM?si=d8nrZZU_dbOAyizD

 

[HoHun]

Hi,

My understanding is that WW2 4 cannon Spitfires were extremely rare (especially in service rather than tests etc.), even if a theoretical option structurally.

It seems a number of them were sent to Malta, where they suffered from serious stoppage problems and routinely had the two outer cannon removed. The wish for a better climb rate might have had something to do with that, too. I recently read somewhere that the RAF even requested the extra cannon stockpiled on Malta to be sent back to Britain, as they were a bit short on Hispanos there at the time.

The stoppages might have been at least in part due to the effects of the cold at altitude, as I seem to remember reading that the hot air ducts for gun heating would only provide hot air for the two inner cannon.

In establishing the 2-cannon-plus-machine-guns wing as standard, it might have played a role that the pilots over Malta found it very frustrating that when the cannon failed, they were left without any weapon at all. This had been an issue with the first cannon Spitfires during the Battle of Britain too, so I wonder if the idea was to have a reliable and proven backup weapon, as even rifle-calibre guns were better than no guns at all.

All of this is from memory, which tends to be unreliably, so please take it with an appropriate dose of salt.

Regards,

Henning (HoHun)

 

[perttime]

Hi,

It seems a number of them were sent to Malta, where they suffered from serious stoppage problems and routinely had the two outer cannon removed. The wish for a better climb rate might have had something to do with that, too. ...
...
Henning (HoHun)

There might be a parallel with Bf 109G.
Germany put wing guns (20 or 30mm) on some Messerschmitts, presumably to function as bomber killers. Some such Bf 109Gs were supplied to Finland, but the wing guns were soon removed. The pilots found that the extra guns reduced aircraft performance and manoeuverability. And they were not fighting heavy bombers anyway.