F.6/42-type fighter, but with Merlin power

[z42]

How much of a difference that would've made for, let's say, 1940?

For about the same weight of the historical 8x.303 armament they could have 1x20mm Hispano motor cannon, and 4x.303 in the wings. And since the early reliability issues of the Hispano were apprently largely due to wing flex and being mounted on the side to make the drum magazines fit, this wouldn't have been a problem with a motor gun installation. I think this armament would have a significantly better punch than the historical one, particularly against bombers.
As for what difference it would have made to the war, hard to say. RAF obviously won the BoB regardless, but with a punchier armament I guess they would have extracted a higher toll on the Luftwaffe, particularly bombers. Would that have led to Luftwaffe gritting their teeth and eating up higher losses, or would they have given up on BoB sooner, hard to say.

 

[z42]

People have a fascination with the radiator under the fuselage, I guess because of the P-51.

But not all under fuselage radiator set-ups were great.

The Hawker Hurricane's worked OK. The Hawker Tornado's didn't work at all well, and it was moved to the chin.

The XP-40 had an under fuselage radiator when it first flew, but not long after it had a chin radiator.

The under fuselage radiator would be in the area that later Spitfires would have their rear fuselage tanks.

True. Meredith's paper came out in 1936, and suspect the reality was that it took a few years of head-scratching before people really understood how to design a radiator making maximum use of it like the P-51. That being said, I still think it would in the mid-30'ies have been possible to design a ventral radiator with less drag than the wing-mounted radiators on the Spitfire, just on account of having available the large fuselage volume (large compared to the wing, that is) to hide the radiator in. I mean, even if the Meredith effect wasn't understood, the advantage of a diffusing duct entry to the radiator core was surely known?
Or what about an FW190-style annular radiator? Would it have been feasible to design such a thing in the mid-30'ies?

 

[tomo pauk]

For about the same weight of the historical 8x.303 armament they could have 1x20mm Hispano motor cannon, and 4x.303 in the wings. And since the early reliability issues of the Hispano were apprently largely due to wing flex and being mounted on the side to make the drum magazines fit, this wouldn't have been a problem with a motor gun installation. I think this armament would have a significantly better punch than the historical one, particularly against bombers.

For this scenario to work, the timely supply of Hispanos is needed.

 

[z42]

For this scenario to work, the timely supply of Hispanos is needed.

Sure. But if the RAE/RAF would have required inline engines be equipped with a motor gun tube, it seems reasonable they would also have taken steps to make available a suitable gun for that position.

 

[MikeMeech]

True. Meredith's paper came out in 1936, and suspect the reality was that it took a few years of head-scratching before people really understood how to design a radiator making maximum use of it like the P-51. That being said, I still think it would in the mid-30'ies have been possible to design a ventral radiator with less drag than the wing-mounted radiators on the Spitfire, just on account of having available the large fuselage volume (large compared to the wing, that is) to hide the radiator in. I mean, even if the Meredith effect wasn't understood, the advantage of a diffusing duct entry to the radiator core was surely known?
Or what about an FW190-style annular radiator? Would it have been feasible to design such a thing in the mid-30'ies?

Hi
The "Meredith" ideas were already incorporated in the Spitfire design before it flew as indicated in various books on the Spitfire, for example Morgan and Shacklady's 'Spitfire The History:

And Alfred Price's 'The Spitfire Story':

That the Mustang radiator was 'better' should be no surprise as it was a much later aircraft that could incorporate the experience gained by the British, along with the British finance for the design.

Mike

 

[tomo pauk]

Sure. But if the RAE/RAF would have required inline engines be equipped with a motor gun tube, it seems reasonable they would also have taken steps to make available a suitable gun for that position.

This was kinda my point - RAF needs to make their mind wrt. cannon armament some 5-10 years earlier in order for the motor-cannon idea to take root.
In case that RAF goes with Oerlikon FF or L, they can have a pair of those in the wings of the Hurricanes and Spitfires by day one, making the motor-cannon idea moot. Same for the radial-powered fighters, while 4 can be installed on 2-engined fighters. All well before ww2 starts out.

 

[BarnOwlLover]

As far as the fuel tank in the fuselage, I understand why a lot of British fighters used them--it freed up room in the wings for landing gear (Spitfire designers and certainly Camm at Hawker had a fascination with having the landing gear behind the front wing spar) and allowed for mounting at the aircraft's CG. Of course, self sealing tanks were standard by the Battle of Britain, but those were generally proof against rifle caliber projectiles and flak fragments. How did British self sealing tanks do against cannon shells or large caliber MG rounds?

I know that some US tanks could stop leaks from .50-class rounds or 20mm shells, ie, weapons comparable to their own. But was this true of British fuel tanks? It does seem that most German fighters or Japanese fighters weren't proof against .50 rounds, let alone 20mm HE, HE-I, ball, AP or AP-I shells.

 

[Shortround6]

Spitfire designers and certainly Camm at Hawker had a fascination with having the landing gear behind the front wing spar)

In the case of the Spitfire you have to look at the wing construction. Everything forward of the "wing spar" was actually part of the spar. It was called a "D" spar and the wing nose skinning actually contributed to the strength of the spar, especially in resisting twisting loads. This needed more attention as speeds went up. However cutting big whacking holes in the "D" structure to hold landing gear bays would have called for considerable redesign.

How did British self sealing tanks do against cannon shells or large caliber MG rounds?

Not well, of course the US tanks may not have done all that well either.

Make sure any test results specify the type of gun used and ammo and the condition of the tank/s. Full or nearly full are going to give different results than 1/2 full or nearly empty.
There is a reason all the YouTube video gun channels like to show stuff getting shot filled with liquids. Shooting empty cans/jugs/bottles is kind of boring.
The big .50s (US and Russian) can split the seams of nearly full tanks depending on the size of the tanks and the where the bullet/s go through the liquid (over or along the surface vs deep).
20mm shells very considerably in weight, velocity and HE content. Find the video of the recovery crew of the Glacier Girl crew firing a 20mm round at a partially filled steel 55 gallon drum. Now figure out how to seal up what was left.

 

[BarnOwlLover]

Makes me think that mounting big fuel tanks ahead of the pilot may not be such a good idea. Good for the aircraft's trim and CG, maybe not so much for pilot survivablity.

 

[z42]

Makes me think that mounting big fuel tanks ahead of the pilot may not be such a good idea. Good for the aircraft's trim and CG, maybe not so much for pilot survivablity.

Hey, somebody said something along those lines earlier in this thread: F.6/42-type fighter, but with Merlin power

 

[Shortround6]

Makes me think that mounting big fuel tanks ahead of the pilot may not be such a good idea. Good for the aircraft's trim and CG, maybe not so much for pilot survivablity.

Everything is a compromise.
The IL-2 was about as armored as a plane can get and still fly.
Germans complained how tough they were to shoot down.
Russians admit to 11,570 losses.

As mentioned up thread, not getting hit due to superior performance (includes maneuverability) is a from of protection.
However it does require you to keep the level of superior performance and pilot training.

 

[z42]

Not well, of course the US tanks may not have done all that well either.

Make sure any test results specify the type of gun used and ammo and the condition of the tank/s. Full or nearly full are going to give different results than 1/2 full or nearly empty.
There is a reason all the YouTube video gun channels like to show stuff getting shot filled with liquids. Shooting empty cans/jugs/bottles is kind of boring.
The big .50s (US and Russian) can split the seams of nearly full tanks depending on the size of the tanks and the where the bullet/s go through the liquid (over or along the surface vs deep).
20mm shells very considerably in weight, velocity and HE content. Find the video of the recovery crew of the Glacier Girl crew firing a 20mm round at a partially filled steel 55 gallon drum. Now figure out how to seal up what was left.

There was a youtube video just a few days ago dealing with US vs Japanese self-sealing fuel tanks at
View: https://www.youtube.com/watch?v=aAd13RLLQqs
Bottom line seems to be that US tanks were designed to withstand a .50 hit. A 20mm shell is going to have a lot more kinetic energy than that, make a bigger diameter hole, and the chemical energy and shrapnel from the HE on top. Then again, I can imagine self-sealing tanks would be useful against the shrapnel and blast effects from a non-direct hit by a cannon shell.
I also wonder what would be the best and worst cases wrt how full the tanks are? A full tank will lead to more hydrostatic shock that might burst open the tank itself, OTOH a partially filled tank will have the empty space in the tank filled with fuel vapor (usually too rich to ignite directly, but given a source of additional oxygen and heat like an API bullet or HE shell..).

 

[tomo pauk]

Makes me think that mounting big fuel tanks ahead of the pilot may not be such a good idea. Good for the aircraft's trim and CG, maybe not so much for pilot survivablity.

P-47 and F4U: hold my beer

 

[Shortround6]

I noticed the test MG about 2:52-2:56 in the video is the smallest .50 cal I have ever seen

 

[BarnOwlLover]

But then again, what of all the pilots who sustained burns in the Battle of Britain when the fuselage tanks got punctured. Granted, armor and fuel tanks on the Spitfire and Hurricane improved during the war, but still. And as the war went on, rifle caliber MGs were replaced with .50 class MGs, 20mm HV cannons and 30mm LV cannons.

And as pointed out above, .50 BMG ball or AP/API ammo was capable of over-pressuring fuel tanks on even German fighters, let alone most Japanese aircraft, even those that had self sealing tanks.