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

[wuzak]

They were still installing the ridiculous rear view mirror as late as the Mk.21. How many miles of range did that thing eat up?

By itself, probably not that much.

Probably less than the cost of the protruding cannon barrels.

But there are several areas where small improvements could have been made, which would have added up to something useful.

Unfortunately the desire to keep production moving rapidly meant that many possible updates weren't applied.

 

[Geoffrey Sinclair]

Assuming the fuel available for range is exactly that, the 15 minutes allowance is for a climb over the airfield, the fuel economy figures look too good and are inconsistent, the way the mark II is worst then best depending on speed.

Performance Tables of British Service Aircraft, Air Publication 1746, dated August 1939 but data includes 1940/41 aircraft. The ranges of fighters are shown as ranges at maximum economic cruising power on the fuel available, after deducting fuel used in 15 minutes at maximum power at sea level. This allowance is for warming up and climbing to operational height. The above makes no allowance for - (i) The effect of wind, (ii), The effect of formation flying, (iii) The use of full throttle over enemy territory. The effect of these factors must be allowed for when fights are being planned.

Spitfire	I	IIa	Vb
Cruising Speed (m.p.h)	304​	314​	310​
Cruise Speed Height	15,000​	15,000​	15,000​
Range (15 mins allow.) (miles)	415​	335​	335​
Fuel (for range, gallons)	64.53​	57.48​	54.01​
Fuel (for range, pounds)	484​	414​	389​
Fuel (for allowance, pounds)	146​	191​	216​
Fuel (Total, pounds)	630​	605​	605​
Fuel (Total, Gallons)	84​	84​	84​
Miles per gallon	6.43​	5.83​	6.20​
x	x	x	x
Speed (m.p.h)	180 - 190	180 - 190	180 - 190
Height (feet)	15,000​	15,000​	15,000​
Range (15 mins allow.) (miles)	575​	530​	480​
Fuel (for range, gallons)	64.53​	57.48​	54.01​
Fuel (for range, pounds)	484​	414​	389​
Fuel (for allowance, pounds)	146​	191​	216​
Fuel (Total, pounds)	630​	605​	605​
Fuel (Total, Gallons)	84​	84​	84​
Miles per gallon	8.91​	9.22​	8.89​

On the above figures, give the mark I 124 gallons of 87 octane fuel and the range is around 930 miles, less deductions for carrying the extra weight, give it 100 octane and add more range (And deduct 0.3 pounds per gallon from the weight). One report I have is Spitfire I range 395 miles including combat allowance.

One RAF report gives the Mustang I with the F3R engine a range of 990 miles at 15,000 feet, with 153.2 imperial gallons of fuel, which the above figures suggests the Spitfire I could have managed with around 131 Gallons. Now the Spitfire I tare weight was around 1,640 pounds less than the P-51A empty weight but somehow it does not seem correct the energy required to move that extra weight 3 miles up comes to over 20 gallons of fuel.

Economic cruise	VIII	IX	difference
Range (miles)	660​	434​	226​
Fuel (gallons)	124​	85​	39​
Miles per gallon	n/a	n/a	5.79​

Spitfire VIII cruise 20,000 feet, 320 mph, 66 gallons per hour, 4.85 mpg.

The Spitfire VIII increased internal fuel by 45.8% compared to the mark I, the P-51B increased internal fuel by 46.2% compared to the P-51A

The Spitfire 75 gallon rear fuselage tank gave problems as it had plenty of volume for the fuel to move around as the tank emptied, worsening the handling. Something similar would happen with leading edge fuel tanks, with the effects more pronounced the further outboard they are and their capacity. Comments from P-51 pilots about when they considered the rear fuselage tank fuel load was safe for combat and effects on handling as it emptied would be useful.

The Spitfire XII had the biggest engine drawing on the original fuel capacity and so the shortest range, it was meant as a low altitude fighter, to counter the Fw190 hit and run raids. The mark VIII as built has the altitude performance and matches the mid 1943 P-47 range but requires more internal fuel to match the late 1943 and early 1944 range, with that extra fuel known to be possible based on the late 1944 to early 1945 fuel carried in the rear fuselages of mark IX and XVI. By the allied standards of mid 1943 the mark VIII could be described as a long range fighter, as of early 1944 it was a medium range one.

Find the 8th Air Force fuel consumption guides for the fighters, how much fuel for what distance and how the fuel load was distributed between the available fuel tanks.

In 1943 the allied ETO air forces and Luftwaffe trained each other as the Luftwaffe pulled its fighters back to beyond allied escort range and then largely kept that deployment when allied fighter range grew further in late 1943/early 1944. It meant escort fighters could carry fuel loads that would be dangerous in combat well into enemy airspace, unlike the 1941/42 and early 1943 fighting where interception would happen near the coast.

 

[yulzari]

Perhaps we can all at least agree that one can substantially increase the range of the Spitfire,albeit with caveats.

But the Spitfire was not the only RAF option were the demand made. Are there some posts to be made on non Spitfire possibilities? The inability of daylight bombing unescorted was found at the very beginning of the war in 1939 with Wellington operations against the German coast. So the RAF has from late 1939 to make a decision to continue daylight bombing and requires a long range escort fighter to make that possible. At the time the daylight strategic bombing force still was in existence but used Fairey Battles operating from France, so needing less range than heavy bombers from across the North Sea. So the first model would be escort fighters with a range suitable to fly from French bases into western and central Germany. That is very different to the 1943 model of escorting heavy bombers in daylight from East Anglia across the North Sea. So the RAF requirement is not the one posters have assumed hitherto. For this 1939 requirement the problem is not increasing the range but rather making enough interceptor fighters to defend the home islands. IOTL Hurricanes and Gladiators were the fighters sent to France as they were better able to use the short muddy fields offered to the RAF in France behind the front line. Spitfires were being husbanded as the best interceptors and production entirely reserved to build up the home interceptor force. So, if the 1939 RAF is demanding a long range escort fighter to the 1939 model in any realistic time frame, the only in service option into which to squeeze more fuel is the Hurricane. So how far can we take a Hurricane for that task? France falling is not a contingency that anyone would allow for at the time.

Now the IOTL presence of Ju86 high altitude flights over the UK triggered an RAF requirement for a high altitude fighter. The Westland Welkin. This gives us a feasible timescale for the next step when France falls and heavy bombers need to be escorted much farther. This alternative requirement does not carry with it all the high altitude baggage that doomed the Welkin so Petter can give us a Maxi Whirlwind with Merlin's and a larger airframe etc. to pack in the extra fuel whilst avoiding the necessary extra airframe bomber needs of the Mosquito.

Thus we have the OP met with a long range Hurricane initially with a Maxi Whirlwind to follow.

Now one has to note that the RAF did get a very few Lockheed P38 Lightnings as a relic of an order from France. For engine commonality with the P40 Tomahawks similarly ordered they had no turbocharger nor handed engines. The result was uninspiring although one can understand the French reasoning. If they had been sent to USA specification with handed engines and turbochargers they might be an option. Before the patriotic American posters get all excited one has to note the state of development of the Lightning at the time and the risk that the USAAF might refuse to allow any export once the USA is forced to enter the war three years later. Especially in the initial panic and one notes the USAAF in Europe had to have the Spitfire as it's principal fighter at first and Lightnings were in very high demand for long range use in the Pacific.

 

[tomo pauk]

Now the IOTL presence of Ju86 high altitude flights over the UK triggered an RAF requirement for a high altitude fighter. The Westland Welkin. This gives us a feasible timescale for the next step when France falls and heavy bombers need to be escorted much farther. This alternative requirement does not carry with it all the high altitude baggage that doomed the Welkin so Petter can give us a Maxi Whirlwind with Merlin's and a larger airframe etc. to pack in the extra fuel whilst avoiding the necessary extra airframe bomber needs of the Mosquito.

With Westland making Spitfire III from the late 1940 (obviously that never happened), and not messing with anything else, Peter can shove a 30-40 imp gal tank behind the pilot and pronto, there is a LR Spitfire, that uses half the engines the 2-engined fighter will need.

Now one has to note that the RAF did get a very few Lockheed P38 Lightnings as a relic of an order from France. For engine commonality with the P40 Tomahawks similarly ordered they had no turbocharger nor handed engines. The result was uninspiring although one can understand the French reasoning.

British have gotten the type they ordered.
Granted, they also took over the French order; yes, Lighning I story came to a quick end by late 1941/early 1942, and Lightning II for the RAF never materialized.

Before the patriotic American posters get all excited one has to note the state of development of the Lightning at the time and the risk that the USAAF might refuse to allow any export once the USA is forced to enter the war three years later. Especially in the initial panic and one notes the USAAF in Europe had to have the Spitfire as it's principal fighter at first and Lightnings were in very high demand for long range use in the Pacific.

Lightning - with or without turbo - was very expensive fighter in the British eyes. One can understand lack of ... excitement to buy it by the British government once it was clear that it is a nice to have aircraft, rather than a necessity.

 

[Shortround6]

A bit more than you realise, actually. From the firewall aft to the tail section, between Frame 5 and Frame 19 where the tail section fitted to, from the Mk.V onwards, the structure was the same. The modification for high and low back Spitfires was a simple change in the size of frames, but the basic structural elements were the same. Wings, engines, empennage, and cooling systems all changed, but the fuselage stayed the same.

Thank you for the correction/s.

I thought they had strengthened the Longerons. The changes to the tail may have been more to due to the changes in power than the changes in weight. The choice of the MK 47 Seafire was a bad one because a lot of the changes were due to the weight and stress of the powerplant and not simply the payload. It is a strange coincidence that the weights wind up so close but that is all it is.

 

[Shortround6]

With Westland making Spitfire III from the late 1940 (obviously that never happened), and not messing with anything else, Peter can shove a 30-40 imp gal tank behind the pilot and pronto, there is a LR Spitfire, that uses half the engines the 2-engined fighter will need.

Peter can shove 30-40 imp gallons into a Whirlwind, fit a cross feed system and presto, long range fighter

British have gotten the type they ordered.
Granted, they also took over the French order; yes, Lighning I story came to a quick end by late 1941/early 1942, and Lightning II for the RAF never materialized.

By late summer of 1940 (way to late for the French) the British had over 500 (?) Lightnings on order with turbos. As you say they never materialized for various reasons, or rather they materialized as US aircraft. US being short 500 P-38s in the Pacific and North Africa in 3arly 1943????

Lightning - with or without turbo - was very expensive fighter in the British eyes. One can understand lack of ... excitement to buy it by the British government once it was clear that it is a nice to have aircraft, rather than a necessity.

Once they got it sorted out (combat capable) in early 1942 with the self sealing tanks and they had lost 100 US gallons of internal capacity and were working on fitting drop tanks things weren't looking that good for the P-38 as a long range escort. Once they got the sizable drop tanks fitted things got a lot better and with the "J"s with 410 US gal of internal fuel things really got better. The extra 100 gallons was worth around 1 hour at just over 300mph at 25,000ft.

 

[Shortround6]

The war lasted almost 6 years.
Things changed, a lot of things.
Basically the Spitfire needed 3 things to change to be a long range fighter.
1. Be able to fit the fuel in and keep the CG workable.
2. Be able to dogfight (engage in combat) without breaking the plane with G loads.
3. Be able to take-off with the fuel load without breaking anything using the runways of the time.

Now we seem to be considering a number of different times.
1. Fall/winter of 1939 after the failure of the Wellingtons to fly in daylight.
2. Summer of 1941 (?) Luftwaffe has gone off to Russia and the RAF can consider something besides the lean into France?
3. Summer of 1942 and the Merlin 61 offers a lot more power changing the power to weight situation?
4. Summer of 1943 and the US showing the possibility of daylight bombing but also showing the pitfalls and the need for a long range fighter that can be introduced in a number of months (winter of 43/44).

Now looking at the 3 aircraft problems in the first time period there is not a real problem in fitting in 30-40 more gallons. No real reason they could not have made the bottom fuselage tank bigger, stick a tank behind the seat? it was done, may be there was less radio gear? Maybe you need a bit of ballast in the nose?
30-40 gallons is going to affect climb, perhaps turn a little, unlikely to break the plane, A MK I is still pretty light, they have not added a lot of extra stuff.
Problem may be taking-off. Fit the constant speed props and that pretty much solves that problem. Runways will get better as time goes on although unpaved runways lasted quite a while. Now does 30-40 gallons solve the problem of escorting the bombers or not (in the winter of 1939/40 or into 1940?). If it is not enough fuel what is the next step?

More later.

 

[NevadaK]

Literally no one has said that.

You seem to be forgetting that the long range Mustang didn't come around until the winter of 1943/4. That's four years of war for the RAF. Re-read the thread title.

Perhaps, but the original post said it shouldn't be based on either the Spitfire or Hurricane as well and should be British implying that there would be no Mustang.

 

[Thumpalumpacus]

The main reason for the long range in PR Spits was the leading edge tanks fitted to them. Each held 66 Imp.G. So the PR Spitfires had more than twice the fuel of the fighter variants,

It would be possible to modify the standard wing to have more fuel, in addition to the small ~13.5 Imp.G fuel tanks inboard of the gun bays.

To use the leading edge of the wing would require them to standardise on 2 x 20mm cannon + 2 x 0.50" hmgs, or 4 x 20mm cannon. These gun positions are close together, as compared to the 2 x 20mm + 4 x 0.303" mg arrangement, where the mgs are spaced apart.

The Leading edge tanks - outer and inner - could possible give 40-45 Imp.G.

The question about that arrangement would be how the fuel is fed past the gun bays, and whether it can be done without sacrificing the structural strength of the wing.

The leading edge fuel tanks on PR Spitfires lost some supporting structure, so probably weren't as good for manoeuvring.


The other way the range could be increased is by reducing drag.

The Spitfire III was an attempt to do this, with a redesigned radiator, clipped wings and other detail changes.

But many of these features did not go beyond the Mk.III prototype.

Thanks, this was the reply I'd been hoping for.

 

[Thumpalumpacus]

You can say anything you like, but support it with facts rather than bias. Here's something that we can agree on, the Spitfire was not an ideal long-range escort fighter, simply because it was not designed for that role.

Here's the clincher that I feel you're refusing to acknowledge, that doesn't mean that there was no way it could have been one. With modification it could have easily become a suitable long-range escort fighter, had the need arisen, but the need did not arise, therefore it was done as an exercise only and not done for service. It's the nuance that's missing.

To demonstrate fairness, don't get me started on the problems that beset the Typhoon or the Halifax...

Well, then perhaps you should have explained above why using those examples was indeed apt. I'm all for communication, provided it's not snide or condescending. Also, I newer wrote that it couldn't be done, If you wish to assert otherwise, please link to that post of mine. Go ahead and review my posts.

 

[tomo pauk]

Peter can shove 30-40 imp gallons into a Whirlwind, fit a cross feed system and presto, long range fighter

30-40 imp gals extra provide far better mileage for a 1000-1300 HP fighter than they do for a 1770-2000 HP fighter, that is also heavier and draggier.
I know you like the Whirly

By late summer of 1940 (way to late for the French) the British had over 500 (?) Lightnings on order with turbos. As you say they never materialized for various reasons, or rather they materialized as US aircraft. US being short 500 P-38s in the Pacific and North Africa in 3arly 1943????

I'm not championing that RAF gets Lightnings of any flavor.

Once they got it sorted out (combat capable) in early 1942 with the self sealing tanks and they had lost 100 US gallons of internal capacity and were working on fitting drop tanks things weren't looking that good for the P-38 as a long range escort. Once they got the sizable drop tanks fitted things got a lot better and with the "J"s with 410 US gal of internal fuel things really got better. The extra 100 gallons was worth around 1 hour at just over 300mph at 25,000ft.

Thank you.
100 US gals = 84 imp gals = 42 imp gals per engine.
Math for the Spitfire is similar - sleek aircraft with frugal engines benefit even from small increase of internal tankage.

 

[EwenS]

By late summer of 1940 (way to late for the French) the British had over 500 (?) Lightnings on order with turbos. As you say they never materialized for various reasons, or rather they materialized as US aircraft. US being short 500 P-38s in the Pacific and North Africa in 3arly 1943????

AIUI while Britain took over the whole contract in June 1940, it wasn't until the experience of the BoB was analysed that the turbo version was seen as the better option. Discussions to change the contract with Lockheed only began in Spring 1941 and became "heated". As a result it was 5 Aug 1941 before a modified contract was signed. That provided for the first 143 to be delivered as turboless Mk.I and the remaining 524 as turbo Mk.II.


Then in late summer 1941 revelations about handling problems in the YP-38 flight test programme led to Britain trying to cancel the contract altogether but Lockheed holding them to it. Apparently discussions reached a stalemate in Nov. As far as this contract was concerned, Britain was saved by Pearl Harbor and the USAAF taking over both the aircraft already built and the contract.

Ultimately 3 Mk.I for trials at the RAE & A&AEE, arrived in Britain in March 1942. 19 more were designated as RP-322-I by the USAAF and used for test and training. The next 121 were given handed props and designated RP-322-II and used as trainers.

The other 524 intended to have the turbo engines were completed as
1 test aircraft
28 P-38F-13
121 P-38F-15
174 P-38G-13
200 P-38G-15

These latter 2 blocks were similar to the G-3/5 but were given separate identifiers as they came from different contracts.

 

[SplitRz]

Both Beaufighter and Boston were bad in bombing Germany.
British war started in 1939, not in 1941.

Errr, I know, being British and understanding the basic strategic situation and the aircraft they had access to prior to that. The catastrophic losses of ESCORTED Blenheims on even short range forays over occupied Northern Europe in late 40 early 41 proved the dangers of even those limited raids. Trying the same with Wellingtons or Hampdens all the way through to Germany and at relatively low level was only going to have one outcome, wundar-escort or not.

The P-38 was initially seen as the long-range fighter for U.S. forces in Europe.

Bomber Command had been bombing mostly at night since the autumn of 1940. If the bombers are going at night, there is little pressure or need to develop a long-range day fighter.

Precisely.

 

[tomo pauk]

Errr, I know, being British and understanding the basic strategic situation and the aircraft they had access to prior to that. The catastrophic losses of ESCORTED Blenheims on even short range forays over occupied Northern Europe in late 40 early 41 proved the dangers of even those limited raids.

There is no point in making a half-arsed effort wrt. escorted bombing. Either mass your aircraft - both fighters and bombers - or don't bother.
Of all British bombers worth speaking about, only Fairey Battle have had lower defensive firepower than Blenheim, so using Blenheim as a benchmark for survivability is damning with a faint praise.

What exact losses were suffered by TAF's Blenheims in late 1940-41?

Trying the same with Wellingtons or Hampdens all the way through to Germany and at relatively low level was only going to have one outcome, wundar-escort or not.

Before other people interject (I know they will try ) - what cruising altitudes we're talking about for Blenheim, Wellington and Henley in 1939-41?

edit: Hampden, not Henley

 

[Shortround6]

Henley

??????

Of all British bombers worth speaking about, only Fairey Battle have had lower defensive firepower than Blenheim,

Blenheims were very mixed bag. Early ones had Lewis gun but that may never have seen combat. Then came the Vickers K gun. almost double the rpm. Then came two Vickers K guns.
Some got a pair of Brownings in the powered mount/turret which beat the heck out of Hampden, at least in upper half of the defensive area.
The Wellington IC got the 4 gun power turret into service some time in 1940. Photos of some MK IIs (Merlin engines ) show 2 gun rear turrets.

Problem with the British escorting bombers in April/May of 1940 was that it took a while to understand the escorting bombers DID NOT mean sending a fighter sweep through the area plus or minus 15 minutes of when the bombers were supposed to show up.

But two Brownings, even in a power mounting were not enough, even though that is what SBDs had (minus the power traverse and elevation)

 

[pbehn]

Problem with the British escorting bombers in April/May of 1940 was that it took a while to understand the escorting bombers DID NOT mean sending a fighter sweep through the area plus or minus 15 minutes of when the bombers were supposed to show up.

Or, to summarise...... Leigh Mallory

 

[nuuumannn]

Thank you for the correction/s.

I thought they had strengthened the Longerons. The changes to the tail may have been more to due to the changes in power than the changes in weight. The choice of the MK 47 Seafire was a bad one because a lot of the changes were due to the weight and stress of the powerplant and not simply the payload. It is a strange coincidence that the weights wind up so close but that is all it is.

It's quite alright, your knowledge and wisdom is humbling and I look to your posts for much good stuff. We all cock up every now and then...

 

[Admiral Beez]

What kind of max range can we get on the Whirlwind? And more ammo.

 

[wuzak]

It's quite alright, your knowledge and wisdom is humbling and I look to your posts for much good stuff. We all cock up every now and then...

Didn't Griffon Spitfires get stronger longerons?

Maybe made of steel instead of aluminium?

 

[Shortround6]

What kind of max range can we get on the Whirlwind? And more ammo.

The ammo was not a problem. They trialed a version with 110-120 rpg with a powered feed system, The feed system didn't work but there was room for more ammo.
They drew out a scheme for two fuselage tanks, one before the cockpit and one aft. No idea if would actually work.
Short of extending the wing to make more room for fuel that is about the only option.

But lets face it. We are dealing a plane whose wing was about 1/2 way between a Spitfire and Hurricane and you started with just under 1800hp engines if they are not upgraded. It was a very small twin.
It was never intended to be along range fighter like we are talking about although it did a bit better than the Spit and Hurricane in their 1940/41 forms.