British escort fighter--what might it have been like?

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Tell Hawkers to build the P-509 in 1939/40, then build P-51Bs instead of Spitfire Mk IXs, you have an allied escort available in numbers in 1943 so long range penetration missions can start 1 year earlier than they did historically. The British didnt have any need for a long range escort, the Americans only realised they had a need in 1943.
Or simply get Hawkers to fit aux tanks into Spitfires like all production MkXVI's had. Everyone wants to reinvent the wheel, just put more fuel in the Spit, easy.
 
Especially since I'm basically asking for not extending the range of say a Spitfire, but basically a clean sheet of paper design.
Just using the Spitfire as a benchmark. Hopefully your team can beat it, But look at the Hurricane with the same engine if you cannot ;)

The Spitfire was actually pretty good and helps illustrate some of the problems. Like I have tried to show, 1939 had a number of limitations that went away by 1941/early 1942.
Typhoons in 1942 were not a good idea. The engines weren't lasting very long. Operational range was not good. Think about it, you had the internal fuel of an Allison Mustang and you had an engine that burned fuel like P-47 or the two engines in a 1942 P-38. Not a recipe for long range escort no matter how fly you could fly it at 210-240mph at 10,000ft.

You have to be careful with the drop tanks. If you hang a pair of 90 gal tanks under a Typhoon you can get in further than you can get out for example.

Also be careful about a "baby", lightweight Tempest/Fury. sounds good but............how do you make it light weight? leave out guns or ammo? leave out fuel?
take airplane designed for 2300-2500hp engine and try to use a 1600hp engine of much lighter weight? Won't work in the large, heavy airframe.
P-51D held about 10% more fuel in the inside tanks than a Sea Fury II did. The Sea Fury was using a 280 sq ft wing.
The Sea Fury wing weighed 1854 lbs, a P-51D wing weighed 1066 lbs. a later P-40 wing was around 1120lbs.
Basically you have to throw out everything, design a new smaller structure, and figure out how you can put the fuel in the wings because if you shrink the Fury's wing you can't fit quite as much fuel in the wing tanks. because the wing is thinner. (Mustang actually used a thicker wing percentage wise).
 
Or simply get Hawkers to fit aux tanks into Spitfires like all production MkXVI's had. Everyone wants to reinvent the wheel, just put more fuel in the Spit, easy.
My idea gets you a better plane than the Hurricane by end 1940, it is also better than a Spitfire Mk V when fitted with the same Merlin, it gives as many tactical recon planes as anyone would ever need and as I said an escort for the USAAF day offensive in 1943.
 
I wonder if I should re-word/refocus on "endurance" rather than "range". Range is of course the distance a plane can fly on fuel under whatever specified conditions. Endurance is how long it can fly under those same conditions, which accounts for take off, cruse, a certain amount of combat or loiter time, return and landing.

This also might lead me to rethink some of the stuff I was looking at for my prospective fighter in that thread. Namely in that case that increased internal fuel does give more options (partial fuel for interceptor missions, better carriage of bombs/rockets/ similar stores for short range ground attack/close support missions, etc). This can open up possibilities for discussion here, too. Especially since I'm basically asking for not extending the range of say a Spitfire, but basically a clean sheet of paper design.
Most European fighters of the late 30's did not have a great deal of rang and it won't be easy to get one from the drawing board.

The USAAC's P-36A had a little better range than it's contemporaries, but still not enough to escort bombers, intercept amd engage enemy fighters and still make it home.

The late 30's solution for a long range escort, was the "heavy fighter", which was a twin engined type, typically two (or three) crew aboard.

As the war progressed, engine technology advanced quickly, allowing single engined aircraft the ability to travel further. Not because they were economical, but because they were powerful enough to haul the weight of extra fuel (including the drag penalty imposed by drop tanks).
 
I wonder if I should re-word/refocus on "endurance" rather than "range". Range is of course the distance a plane can fly on fuel under whatever specified conditions. Endurance is how long it can fly under those same conditions, which accounts for take off, cruse, a certain amount of combat or loiter time, return and landing.

This also might lead me to rethink some of the stuff I was looking at for my prospective fighter in that thread. Namely in that case that increased internal fuel does give more options (partial fuel for interceptor missions, better carriage of bombs/rockets/ similar stores for short range ground attack/close support missions, etc). This can open up possibilities for discussion here, too. Especially since I'm basically asking for not extending the range of say a Spitfire, but basically a clean sheet of paper design.
In British service the 180 gallons of internal fuel in the Mustang I and II translated to approx. 90 miles in from the coast on tactical recon missions.
 
I haven't suggested the Spitfire V anywhere in this thread.
But in 1941/early 1942 it is the only game in town.
The two stage engines aren't there yet and the two speed engines don't really buy you that much once you start using 14-16lbs of boost. A Merlin XX will give you about 100hp more for take-off than the Merlin 45 will but in 1941 you have the constant speed prop and you have the somewhat bigger airfields.
The Merlin XX will give you about 1500-2000ft more altitude than the Merlin 45 will. Better but is it really a game changer?

Even a clean sheet of paper design will be using the Merlin 45 family or the Merlin XX family until the Merlin 61 shows up.
 
I also think that I may have to accept that a "lightweight" fighter may not be achievable in how I originally envisioned it. The Lavochkin La-9 and -11 were long range fighters that weighed less than 8000 lbs, but they were kinda outliers in that (like most Russian fighters of World War II) was dimensionally compact, and was designed to be a long range aircraft and not much else. Western nations accepted that by the end of World War II that fighters had to be capable of being air superiority fighters, interceptors, close support aircraft and, if need be, escort or recon aircraft.

As far as modifying what was around in 1945, a more general purpose version of the Ta-152H or a cannon armed P-51H Mustang would probably be best. Or a single seater that's basically half a DH Hornet or F-82 Twin Mustang in terms of weight and range and capability would be great.

Also, size for high speed combat isn't a huge impediment by War's end. The Mitsubishi A7M was intended (and seemed to have achieved) agility at combat speeds of the A6M Zero, in spite of being nearly twice as heavy. That was done due to a low wing loading for its size due to a large wing, and it made nearly twice the power as the Zero. It also used "combat flaps" that could be used in combat to improve agility (something that I do look at here and with the other prospective fighter thread I made).

Also, the La-9 and La-11 might have been smaller, but it was just as (if not more) highly loaded than larger western aircraft designed for similar roles. Same for the ultra-lightweight (for late World War II) Yak-3.
 
But in 1941/early 1942 it [Mk.V] is the only game in town.

I've suggested the Mk.III, since it offered improvements that reduced the drag vs. Spitfires being produced in the time of interest, like the internal BP glass, wheel well covers,retractable tail wheel. It also carried more fuel, 99 vs. 84 imp gals. Even if we install Merlin XII on the Spitfire III it will out-pace and out-range the Spitfire I and II handily, even more so the Bf 109E, and compete well against 109F1 and F2.
With a better carb and more streamlined exhausts it will gain another 10-15 mph.

The two stage engines aren't there yet and the two speed engines don't really buy you that much once you start using 14-16lbs of boost. A Merlin XX will give you about 100hp more for take-off than the Merlin 45 will but in 1941 you have the constant speed prop and you have the somewhat bigger airfields.
The Merlin XX will give you about 1500-2000ft more altitude than the Merlin 45 will. Better but is it really a game changer?

Merlin XX offers next to nothing wrt power over 15000 ft (it is much better down low) before 1942. What changes the game is the fact that it was available good 6 months before the Merlin 45, so we don't have to wait until 1941.
The Merlin 45 on a Spitfire III + better carb + better exhausts also makes sense.
 
Of the fighters that existed, the Spitfire. Another 40 imp gal behind the pilot, drop tank facility.
Defiant. Replace the turret with a big gas tank. Eight mgs in the wings.

defiant-bpa4.jpg
 
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Defiant. Replace the turret with a big gas tank. Eight mgs in the wings
You get a fuel tank behind the center of gravity, planes get's more nose heavy as you burn fuel (original tanks were in the wings where you want the machine guns to go)
Unless you redesign the airplane it is heavier (poorer turning and poorer climbing) and slower than Hurricane using the same engine.

You have do more than just show up, you actually have to fight at least even odds.
 
You get a fuel tank behind the center of gravity, planes get's more nose heavy as you burn fuel (original tanks were in the wings where you want the machine guns to go)
Unless you redesign the airplane it is heavier (poorer turning and poorer climbing) and slower than Hurricane using the same engine.
Ah, but if you put the machine guns where the large fuel tank is proposed to go and keep fuel in the wings then you might as well use a small turret as their mounting and then…………….

The actual experimental single seat x8 wing mounted machine guns Defiant presumably just had a small tank then?

For a long range single seat Defiant you would presumably move the pilot back a bit and give it a fuel tank in front of the pilot plus a small one behind him to draw upon in the initial climb and early stages of the flight, re trimming as it empties. Plus look to a couple of wing mounted drop tanks. The Defiant having a ventral radiator. Or possibly use a chin radiator (Merlin power egg?) to balance the weight of a rear tank? Someone will doubtless now suggest this as a new Fleet Fighter.
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I am with tomo pauk,

In 1940-42 the Spit Mk III with the Merlin XX is probably the best the British could do pre-Merlin 60 series. Strengthen the airframe (if needed) for under-wing 30 Impgal DTs and carry the 30-45 Impgal combatable conformal SSDT on the centerline. The underwing DTs are used for getting to the target, and the centerline SSDT is carried through combat. With 129 Impgal fuel (99 internal + 30 Impgal in the SSDT) this should allow an ROA of 350-400 miles with combat and reserve.

Whatever the airframe used, it will have to be able to operate at or above the critical altitude of the bombers being escorted. The Merlin XX had a critical altitude of ~18,250 ft and at this time no British heavy or medium bomber had engines with a higher critical altitude. The Halifax Mk II with Merlin XX entered service in October 1941 and flew its first missions in November? The Lancaster Mk I with Merlin XX did not enter service until February 1942, and flew its first missions in May?
 
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The actual experimental single seat x8 wing mounted machine guns Defiant presumably just had a small tank then?
It does not appear that there was a "actual experimental single seat x8 wing guns". any photos of a Defiant without turret are the original prototype modified back to a single seater.

I don't know why it happened but while this proposal said the Defiant would hit 364mph with the Merlin XX engine the service Defiant IIs with turrets and Merlin XX engines only picked up about 9mph over the MK 1 (313mph/19,000ft vs 303mph/17,000ft). I don't know if it was the radar aerials, the flat black paint, the bigger air scope/inlet or what.
The Air Ministry said no to it on Sept 20th 1940 which should tell us something.

This idea is like a vampire that somebody tried to kill with a plastic stake, it keeps coming back to life ;)
 
I've suggested the Mk.III, since it offered improvements that reduced the drag vs. Spitfires being produced in the time of interest, like the internal BP glass, wheel well covers,retractable tail wheel. It also carried more fuel, 99 vs. 84 imp gals.
99-1.jpg

Some of this stuff was incorporated on later MK Vs
Spitfire_Mk_III_2.jpg

Why they kept the external BP glass as long as they did is a bit of a mystery. Of course with the bombing of the Supermarine factory just getting them back into production was a priority. Also some MK Vs were rebuilt MK I & IIs so the fitting of new windscreens may have been a bit hap-hazard.
The MK III wings were also clipped about 1 foot more on each side than the Clipped wing MK Vs (or an error?) I am not sure you want to clip the wings that much if you are trying to build a long range fighter to fly over the bombers?
I also have doubts about the landing gear doors operating off British grass airfield in practice.
I would also note that they did a rather good job of taping over the guns and the cartridge chutes (or there were not guns fitted and the plane was carrying ballast?)

We also have to be very carful of what tests we are comparing as the Merlin Xx and Merlin 45 were both limited to 9lbs of boost in early 1941 and the higher boosts came in later.

I don't believe there was enough difference between the the Merln XX and the Merlin 45 to make much difference once the Merlin XX was in high gear.
Using shorter wingtips like the clipped MK Vs used wasn't going to make much difference to the speed but would give most of the advantages the MK III had.
It might have been easier to build as just required changing the wing tip right at the existing joint rather than modifying the existing wing structure like the MK IIl.
Change the windscreen, anybody can see that was a lash-up.
Comparing a Service MK Va with a few mods might be closer to the MK III than we think. The MK III having a particularly good fit/finish? also no IFF aerials?
Fit the bigger forward fuselage tank as was done later, stick around 30 gallons behind the seat (and re-arrange things).

Improve boost as soon as possible.
Fit small slipper tank that is self sealing? and add small non-self sealing tanks to be dropped as soon as trouble appears or entering enemy air space? Having 130 gallons when entering Holland may better than having 160 gallons climbing out of British air fields?

But we are still talking about just making it to the Ruhr.
 
The MK III wings were also clipped about 1 foot more on each side than the Clipped wing MK Vs (or an error?) I am not sure you want to clip the wings that much if you are trying to build a long range fighter to fly over the bombers?
I also have doubts about the landing gear doors operating off British grass airfield in practice.
I would also note that they did a rather good job of taping over the guns and the cartridge chutes (or there were not guns fitted and the plane was carrying ballast?)

Keep the same wings as on the run-on-the-mill Spitfires.
The wheel well covers should probably do a 120-130 deg 'kink' vs. a 90 deg kink as shown on the photos. Another possibility is to fit the doors like the He 70 and He 112 had (eventually it was done on 20s series Spitfires).
IIRC there was no armament fitted on the Spitfire III prototype.

We also have to be very carful of what tests we are comparing as the Merlin Xx and Merlin 45 were both limited to 9lbs of boost in early 1941 and the higher boosts came in later.

I don't believe there was enough difference between the the Merln XX and the Merlin 45 to make much difference once the Merlin XX was in high gear.

I've noted several times that main advantage of the Merlin XX was the timing, not power available. Merlin XX will give better low-alt performance, too.

Using shorter wingtips like the clipped MK Vs used wasn't going to make much difference to the speed but would give most of the advantages the MK III had.
It might have been easier to build as just required changing the wing tip right at the existing joint rather than modifying the existing wing structure like the MK IIl.
Change the windscreen, anybody can see that was a lash-up.
Comparing a Service MK Va with a few mods might be closer to the MK III than we think. The MK III having a particularly good fit/finish? also no IFF aerials?

Most of the advantages probably lay between the BP glass and U/C being less draggy when in flight. 'Normal' wings will be required since the all-up weight is increased, clipped wings will be a disadvantage.
Why it was persisted with external BP glass and draggy exhausts on the Mk.Vs is anyone's guess.

Fit the bigger forward fuselage tank as was done later, stick around 30 gallons behind the seat (and re-arrange things).

Mk.III was already with 99 imp gals between the pilot and engine. Yes, additional 30 gal tank is a must. Improvement would've been that it feeds the bottom front tank, not the engine directly, making the fuel management easier. Feed the cooled exhaust gasses in the rear tank?

Fit small slipper tank that is self sealing? and add small non-self sealing tanks to be dropped as soon as trouble appears or entering enemy air space? Having 130 gallons when entering Holland may better than having 160 gallons climbing out of British air fields?

But we are still talking about just making it to the Ruhr.

Ruhr is full of valid targets, where Luftwaffe needs to get up and defend if RAF attacks in force.
A slipper tank under the belly adds a lot of drag. I'd suggest 30+99 imp gals of internal fuel to be augmented with a 100-110 gal drop tank.
 
Keep the same wings as on the run-on-the-mill Spitfires.
Most of the advantages probably lay between the BP glass and U/C being less draggy when in flight. 'Normal' wings will be required since the all-up weight is increased, clipped wings will be a disadvantage.
You may be right.
They did a comparison of a two Vbs, one with clipped wings and one without. They changed pilots and tested them again. Then they changed the wing tips between the planes and tested again.
at 10,000ft and under the clipped wing was about 5mph faster,
From 15,000ft to 20,000ft they could not measure the difference.
At 25,000ft the the regular wing was slightly faster.
At all altitudes the clipped wing accelerated "rather better".

when doing a zoom climb form 20,000ft to 25,000ft the standard wing was 15 seconds faster.
From 10,000ft to 15,000ft there was no difference

In all dives the clipped wing drew away.

At all heights up to 25,000ft the rate of role was considerably improved. They did for dog fights with the standard Spitfire always starting behind the clip wing. Only in the 4th occasion at 25,000ft was the standard Spitfire even able to keep the clipped wing insight. Twice the clipped wing got on the tail of the standard one in 20 seconds.
Minimum turning circle (?) of the clipped wing Spitfire at 20,000ft has been increased by 55ft at 1,025ft ( FW 190 was measured at 1450ft, RAE figures)

Take off (at normal weight?) no difference detected. and no difference detected in landing.

View over the wingtips," is improved by a not inconsiderable amount."

perhaps the bigger wing will be an improvement at the higher weights, but with any drop tanks gone and some internal fuel used you may have to figure out how high you are going to fighting and what attributes you want to improve.
The wheel well covers should probably do a 120-130 deg 'kink' vs. a 90 deg kink as shown on the photos. Another possibility is to fit the doors like the He 70 and He 112 had (eventually it was done on 20s series Spitfires).
It may be a lot effort not much gain. Once you fix the windscreen you get 5-6mph and unless you take a bullet through the windscreen maintenance is minimal. Same for changing the exhausts. For the small landing gear door you have to make it, make the linkage, install it and them maintain it. Very few people (if any ?) kept hinged doors at the bottom of the landing gear.
I've noted several times that main advantage of the Merlin XX was the timing, not power available. Merlin XX will give better low-alt performance, too.

Well, for timing, in 1940, The RAF doesn't have many bombers to escort. You don't start getting any Merlin XX engines in numbers until late Fall. You start getting Merlin 45s in the spring. Bomber operations over the winter are restricted by weather. Trying to do raids into Germany with a few squadrons of bombers and a handful of fighters (2-3 squadrons) isn't going to change much of anything and unless you can change the RAF training and tactics you are just going to present the Luftwaffe with the same opportunities that the "Lean into France" strategy gave them only earlier and with the British planes having to make it back across occupied country longer.

For the Halifax "Its operational debut occurred on the night of 10–11 March 1941, when six Halifax bombers flew a bombing raid against Le Havre, targeting the area around the docks and any shipping that might be present.[10][28] The existence of the Halifax was not officially acknowledged until July 1941, after it was used in a daylight attack on La Pallice, France, against the German battleship Scharnhorst. At the end of 1941, the Halifax was withdrawn from daylight bombing operations after intensifying fighter opposition had increased the casualty rates to unsustainable levels.

By the end of 1941, more than 150 Stirlings had been completed and three RAF squadrons had been equipped with it.

No you don't need to wait for the 4 engined bombers but for most of 1940 you have Wellington Is, maybe some IIs. The IIIs with Hercules engines (and around 20-30mph more speed) don't show up until 1941.
 
Take off (at normal weight?) no difference detected. and no difference detected in landing.

View over the wingtips," is improved by a not inconsiderable amount."

perhaps the bigger wing will be an improvement at the higher weights, but with any drop tanks gone and some internal fuel used you may have to figure out how high you are going to fighting and what attributes you want to improve.

One of criticisms to the Mk.III (original, with clipped wings) was because of it's increased wing loading.
Fighting altitudes should be between 15 and 20 thousand ft, with a dive now and then when opportunity arises to catch an enemy A/C.


It may be a lot effort not much gain. Once you fix the windscreen you get 5-6mph and unless you take a bullet through the windscreen maintenance is minimal. Same for changing the exhausts. For the small landing gear door you have to make it, make the linkage, install it and them maintain it. Very few people (if any ?) kept hinged doors at the bottom of the landing gear.

Long-range fighters will not be a bulk of the RAF fighters anyway. Let's give the care to the ones tasked with penetrating enemy airspace, and keep the point-defenders (deployed en masse) simpler.

Well, for timing, in 1940, The RAF doesn't have many bombers to escort. You don't start getting any Merlin XX engines in numbers until late Fall. You start getting Merlin 45s in the spring. Bomber operations over the winter are restricted by weather.

Late Autumn, not late Fall.
By Spring of 1941, RAF can have a force of Merlin XX-powered LR fighters, rather than to wait from Spring until the force of Merlin 45-powered fighters is available.
 
My idea gets you a better plane than the Hurricane by end 1940, it is also better than a Spitfire Mk V when fitted with the same Merlin, it gives as many tactical recon planes as anyone would ever need and as I said an escort for the USAAF day offensive in 1943.
The P51 is doing nothing until the 60 series arrives, putting more fuel into the Spit gets you an escort fighter equal to anything in the air and able to fly to the Ruhr and back in the second half of 1942, much earlier than what actually happened.
 

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