Spitfire Combat Radius (range) evolution, limitations?

[Wild_Bill_Kelso]

While 145, 92 and 601 squadrons left Britain on 10-12 Feb 1942, they did not arrive in the Middle East until mid-April (145 & 92) and June (601) as they had to sail via the Cape. There was then a shortage of Spitfires in that area so 145 didn't head up the desert until late May with 601 following in June. 92 had to wait until Aug to receive its aircraft.

The first Spitfires outwith Britain began to be shipped to Malta in March 1942 to equip squadrons already on the island and then to send additional units like 601 & 603 (601 later flying to Egypt to join its ground crews).

On 28 May 1942 Churchill agreed to supply a Spitfire wing to protect Darwin. The squadrons selected were 54, 452(Australian) and 457(Australian). These sailed for Australia in late June 1942 but 42 of the 48 aircraft sent with them were diverted to Takoradi to be flown across Africa to the Middle East to allow 92 to become operational there. So it was late Oct before the first major shipment of replacement aircraft reached Australia. No 1 Fighter Wing then became operational in Darwin from Jan 1943.

Spitfires didn't arrive in India /Burma until Nov 1943.

Ok mea culpa, 145 sqn wasn't there as early as I thought - Mid 1942 for North Africa, and early 1943 for Darwin which I think is what I originally said.

 

[drgondog]

Apparently they could carry a lot of external fuel, and I suspect based on the size, bearcat could get a little further on a gallon of fuel than a P-47 though I'm ready to be proven wrong...

Internal fuel remaining after external tanks dropped determines combat radius. Both will burn about the same amount for warm up, take of, formation assy and start of climb before switching to externals, both will have about the same estimate applied to 'loiter time reserve', both will burn about the same fuel at Combat Power in Radius calcs dropping tanks - but P-47D began ops with 2X internal fuel for -23 and lower dash number and 2.5X internal fuel for P-47D-25 and higher dash number - which was dominant in combat from late 1944 through EOW.

It might have even have a better spc through 20K but P47 had less total drag than F8F. The F4U/F6F/F8F all had parasite drag higher than P-47 but I am not sure about Induced drag as that is more a function of W/L. That said, at cruising speed at high altitude, the CL was pretty low for the P-47D.

F8F was designed as carrier defense, point interceptor, short range (by AAF standards) escort.

 

[GregP]

Ha 1112 have indeed had two (big) 20mm cannons in the wing; post-war. Makes it half as good as the Spitfire VC with 4 (big) 20mm cannons in the wing in early 1942.

The Ha-1112 was developed by virtue of necessity, and I suppose two 20 mm cannons was a decent minimum armament. The Merlin engine precluded nose-mounted guns, so they HAD to come up with SOMETHING. In retrospect, they didn't do badly out of necessity, but the He-1112 was basically a stop-gap airplane so the Spanish would have a fighter to fly until they got jets. In light of that, and also in light of not having to fight in a widespread war, it wasn't a bad solution. Not the best, but not bad, either, to maintain flight-time.

The U.S.A also had some "interim" types a bit later. The F-86D comes to mind with its tray of unguided rockets as armament. The F-89 also sort of floats to the top of the pile as an interim type with less-than-wonderful armament.

 

[Wild_Bill_Kelso]

Internal fuel remaining after external tanks dropped determines combat radius. Both will burn about the same amount for warm up, take of, formation assy and start of climb before switching to externals, both will have about the same estimate applied to 'loiter time reserve', both will burn about the same fuel at Combat Power in Radius calcs dropping tanks - but P-47D began ops with 2X internal fuel for -23 and lower dash number and 2.5X internal fuel for P-47D-25 and higher dash number - which was dominant in combat from late 1944 through EOW.

Fair points. The thing is, the P-47 was specialized as a high altitude fighter, which is a job it didn't do that much of. A lot of the actual air combat in WW2 was considerably below 30,000 ft. I don't think a P-47D series was as good of a fighter at say, 20,000 ft or 10,000 ft as an F8F, do you?

The altitude of the fight depends on what kind of bombing is going on. Tactical bombing of ground targets / armies, means relatively low combat, as does air strikes against naval assets.

It might have even have a better spc through 20K but P47 had less total drag than F8F. The F4U/F6F/F8F all had parasite drag higher than P-47 but I am not sure about Induced drag as that is more a function of W/L. That said, at cruising speed at high altitude, the CL was pretty low for the P-47D.

F8F was designed as carrier defense, point interceptor, short range (by AAF standards) escort.

Maybe 'short range' compared to an A6M, but it seems to have had better range than an F4F, I'd say probably better than an F6, and certainly better than any fighter mark of Spitfire (barring recon versions) which was my actual point. Or any Bf 109. I originally brought up the F8F simply in terms of a balance of performance + range.

 

[tomo pauk]

Knowing how to make one - that can still perform well enough to compete at the highest levels, it's a pretty significant design challenge. I think they kind of got lucky with the high efficiency / low drag design of the Mustang.

I'd chalk the high efficiency / low drag of the Mustang to the talent and hard work of the engineers, technicians and draughtsmen at NACA and NAA, rather than to the luck.
P-47 was also a rangy aircraft once outfitted with drop tanks..

Maybe I'm not reading this chart right, or maybe I've got a poor grasp of what a baseline is for range but Wikipedia says 1,100 miles, and this 1949 document seems to indicate a range in the ballpark of 1500 nautical miles (1726 miles) in 'escort configuration' (3 x external fuel tanks). If I am reading that right, this looks pretty impressive to me. The speed as well, 388 knots at 28,000 ft is 448 mph right?

As for the .50 cals, they could and did put 20mm Hispanos in it. The .50 cals are just another example of 'institutional inertia' you are speaking of specific to the Americans.

Maybe that's not so impressive for 1945, compared to a jet or a P-47M, but my point was exactly that, - this is kind of what they wanted a bit earlier but didn't put it all together in time.

You are reading that right, but there is a host of caveats. Thing is that there was the F8F-1 3-4 years before the F8F-2, that one was under 425 mph, and was armed with 4 HMGs. Yes, it got the cannons later.
For the F8F-2 to be had, P&W needs to design and produce the post-war R-2800-30 engine from the 'E' series.
Ferry range was good, since that meant that drop tanks can be used for as long there is fuel (all 350 gals) in them. The USN combat range, that was supposed to be 679 miles was unworkable for ETO situation in 1940-44, since it presumed inbound cruising at 230 mph at 15000 ft, and outbound cruining at 195 mph at 1500 (!!) ft. USAF for ETO prescribed cruising at 25000 ft, at 310 mph TAS, lest the enemy fighters and/or AAA don't kill you. Having 185 US gals of internal fuel for R-2800 is enough for short-range duties, it compares badly with P-47D bubbletop with 370 US gals, let alone with 265 gals fuel on the most of Merlin Mustangs with a much more frugal engine.
Thing with having almost double the fuel in drop tanks is that that gets one to a position so far away from the friendly airbase where that there is no come back.

US-made Hispano cannon was a victim of bad production tolerances that led to the "light primer strike" problem rendering them very unreliable. For example, British removed the cannons from Mustang IA and installed the British-made cannons instead.

F8F-2 was a fine aircraft, but was way too late for ww2, and it does not solve the USAF problems of escorting the heavy bombers above Europe even if it was available. British have the Spitfire XIV for the high-performance short-range needs, with jet aircraft in the pipeline to take the role from 1945 on.

 

[EwenS]

The F8F-1 Bearcat wasn't built to maximise range. It was built to maximise rate of climb.
F8F-1 4,465 ft/min
F6F-5 2,600 ft/min
P-51D 3,200 ft/min
Spitfire V 4,750 ft/min
Spitfire IX 4,100 ft/min
Spitfire XIV 4,580 ft/min

 

[tomo pauk]

The F8F-1 Bearcat wasn't built to maximise range. It was built to maximise rate of climb.

Bingo.

 

[pbehn]

Well the US had longer ranged fighters than a Spitfire, with the exception maybe of the P-39 and the F2A, the main US Pursuit types like P-40 and F4F, had ~700 - 800 mile range (equivalent of a Spitfire Mk VIII or a bit better). They needed longer still particularly for China and the Pacific, and they kept pushing the boundaries, but the P-51 wasn't the only long-ranged US fighter. The (twin engined) P-38 eventually had a range of 1,000-1,300 miles, the P-47, F6F and F4U each managed ~800 -1,000 miles or (depending on various conditions and configurations).

Arguably the main reason the US were in fact pushing for longer ranged aircraft was the necessity or possibility to have to fight over the Pacific. But the extra range was helpful in many Theaters.

Seeing as Spitfires were being used in North Africa from mid-1942 (actually 145 squadron was there in February) and in the South Pacific by early 1943, they certainly could have used better range. By the time of second El Alamein, the DAF was limited in the use of their Spitfire Mk Vs which flew sorties only half of the days in October. Kittyhawks were having to escort the medium bombers. Toward the end of the battle, P-38s became available in the Theater.

I've already mentioned the range / endurance related issues over Darwin though I could get into more detail.

Seeing as some of the PR Spitfires from the Mk X and XI actually had quite good range, it seems like there should have been some way to make a long range fighter version, maybe a two gun variant would have been possible?

One of the main reasons US planes had a longer range is that the USA is a much bigger country, even in peacetime getting from one airfield to another requires more range. The P-47 was an interceptor at the start what it became is a matter of history. Range is only of use when the performance is there, the P-40 and P-39 were tried by the RAF operating from UK, they just didnt have the performance, while the Mustang Mk I with the same engine did. In RAF service the 180 gallons of internal fuel translated into a "range" on operations of 90 miles in from the enemy coast.

 

[MIflyer]

Note there was a hideous modification to the Spitfire Mk1 that added a large unsightly fixed tank sticking out of one wing to improve the range. And as for size the BF-109 and FW-190 both were smaller than the F4F Wildcat; they did not have a lot of room for extra gas. The RAF considered the Mustang Mk 1 to be huge compered to the Spitfire and Hurricane. When they built the MkXII and XIV they added small gas tanks (12 gal) in the leading edges of the outer wing because the larger Griffin engine consumed so much more fuel than the Merlin, and they did not have that much to start out with. 12 gal sounds almost absurdly small for a gas tank but they needed all they could get.

In the Pacific Lindberg taught first the F4U pilots (as an employee of United Aircraft) and then the P-38 and P-47 pilots to fly at high boost and low revs at low altitude to extend their range, This worked in the Pacific since any long range mission involved most of the flying being over water, an area where the chance of encountering either enemy aircraft or AAA was all but nonexistent and virtually "nought feet" was feasible. The ETO before the Normandy Invasion was nothing like that, with only a little of a mission flying over the Channel and even then having to climb to avoid AAA on the coast as well as inland.

But that same Lindberg approach eventually was adopted in the ETO, after the Allies occupied airfields in France and had nothing to fear from flights over France to ground targets in Germany.

"One of the main reasons US planes had a longer range is that the USA is a much bigger country, even in peacetime getting from one airfield to another requires more range."

Yes, as it has been pointed out, most European fighters of the day could not make it out of Texas without landing to gas up. Even the P-6E could carry an external fuel tank.

 

[Wild_Bill_Kelso]

I'd chalk the high efficiency / low drag of the Mustang to the talent and hard work of the engineers, technicians and draughtsmen at NACA and NAA, rather than to the luck.
P-47 was also a rangy aircraft once outfitted with drop tanks..

P-47 was a lot heavier (10,400 lbs vs 7,650 empty for F8), had a much larger wingspan (40' vs 35') and a much bigger / fatter fuselage. Somebody said it had a lower induced drag or something, I am not an engineer but i find it hard to believe that the P-47 had lower drag than an F8F.

You are reading that right, but there is a host of caveats. Thing is that there was the F8F-1 3-4 years before the F8F-2, that one was under 425 mph, and was armed with 4 HMGs. Yes, it got the cannons later.
For the F8F-2 to be had, P&W needs to design and produce the post-war R-2800-30 engine from the 'E' series.
Ferry range was good, since that meant that drop tanks can be used for as long there is fuel (all 350 gals) in them. The USN combat range, that was supposed to be 679 miles was unworkable for ETO situation in 1940-44, since it presumed inbound cruising at 230 mph at 15000 ft, and outbound cruining at 195 mph at 1500 (!!) ft. USAF for ETO prescribed cruising at 25000 ft, at 310 mph TAS, lest the enemy fighters and/or AAA don't kill you. Having 185 US gals of internal fuel for R-2800 is enough for short-range duties, it compares badly with P-47D bubbletop with 370 US gals, let alone with 265 gals fuel on the most of Merlin Mustangs with a much more frugal engine.
Thing with having almost double the fuel in drop tanks is that that gets one to a position so far away from the friendly airbase where that there is no come back.

Fair points but this again seems to assume strategic bomber escort. A long ranged spitfire wouldn't necessarily be used that way ... I mean it could, but it would help the war effort a lot for example in places like North Africa, Malta, Darwin, New Guinea, China / Burma etc. This was the context from my point of view. Even with 150 gallons that F8F compares very well to a Spitfire or a Bf 109 in range, IMO, while having far more combat capability than say an A6M. If you are flying over the Pacific, through vast areas of China or Burma, or say, from Malta to North Africa or Sicily, you can probably use your drop tanks, though you may have to fly home right after an engagement.

US-made Hispano cannon was a victim of bad production tolerances that led to the "light primer strike" problem rendering them very unreliable. For example, British removed the cannons from Mustang IA and installed the British-made cannons instead.

I'm aware of the problem with the US-made Hispano, It is somewhat incredible that they seem to have had trouble with this long after the war as well. But the context here was not specific to the US, I was just referring to threading the needle between range, agility, and performance. Presumably if they had the F8F flying in say, 1943 the British could have put their own guns in it like they did with the Corsair.

F8F-2 was a fine aircraft, but was way too late for ww2, and it does not solve the USAF problems of escorting the heavy bombers above Europe even if it was available. British have the Spitfire XIV for the high-performance short-range needs, with jet aircraft in the pipeline to take the role from 1945 on.

Again, for me when I'm thinking of the usefulness of something like a longer-ranged Spitfire, I'm not thinking exclusively of strategic bombing escorts to Berlin. I'm not sure you have a better option than a P-51, unless maybe it's a twin-engined fighter like a late model P-38, an earlier incarnation of a F7F, a de Havilland Hornet or something like that.

Most fighter marks of the Spitfire were limited to around 500 miles range which relegated them to the status of point defense fighters or air superiority fighters deployed right at the front line. Something with the combat capabilities of a Spitfire, which were IMO a bit better than a P-51 depending on the specific marks, but with a 1,000 mile instead of 500 mile range, would have been very helpful for tactical escort, fighter bomber, and medium range air superiority missions.

 

[Wild_Bill_Kelso]

F8F-2 was a fine aircraft, but was way too late for ww2, and it does not solve the USAF problems of escorting the heavy bombers above Europe even if it was available. British have the Spitfire XIV for the high-performance short-range needs, with jet aircraft in the pipeline to take the role from 1945 on.

My original point in bringing up the F8F was exactly that - striking such a balance as you see in that aircraft was possible but very hard, and in this example (among many others) came too late to play a role in the war.

 

[Wild_Bill_Kelso]

The F8F-1 Bearcat wasn't built to maximise range. It was built to maximise rate of climb.
F8F-1 4,465 ft/min
F6F-5 2,600 ft/min
P-51D 3,200 ft/min
Spitfire V 4,750 ft/min
Spitfire IX 4,100 ft/min
Spitfire XIV 4,580 ft/min

And yet it still carried almost twice as much fuel as most marks of the Spitfire!

 

[tomo pauk]

Note there was a hideous modification to the Spitfire Mk1 that added a large unsightly fixed tank sticking out of one wing to improve the range. And as for size the BF-109 and FW-190 both were smaller than the F4F Wildcat; they did not have a lot of room for extra gas. The RAF considered the Mustang Mk 1 to be huge compered to the Spitfire and Hurricane. When they built the MkXII and XIV they added small gas tanks (12 gal) in the leading edges of the outer wing because the larger Griffin engine consumed so much more fuel than the Merlin, and they did not have that much to start out with. 12 gal sounds almost absurdly small for a gas tank but they needed all they could get.

Wing areas, in sq ft, (main versions):
- Hurricane: 257
- F4F: 260
- P-51: 242
- Spitfire: 235
- P-40: 236
- Zero: 242
- G.55: 227
- Re.2001 & 2005: 220
- F8F: 244

Smaller fighters:
- Bf 109: 173
- Fw 190: 200
- Soviet fighters: ~185 mostly; Yak 3: 160
- MC.202: 181
- D.520: 171
- MS.406: 170

Yes, wing area is not the be all end all measurement of aircraft's dimensions.

There was a lot of space on the Fw 190 besides the 139 US gals in the main tanks, like the rear fuselage tank, and the volume between the spars. Spitfire fighters with LE tanks have had them in the inner part of the wing, started with Mk.VII.

 

[pbehn]

And yet it still carried almost twice as much fuel as most marks of the Spitfire!

It was almost a decade later in design and started with a 2000+ HP engine, it first flew after jets were in service.

 

[Wild_Bill_Kelso]

It was almost a decade later in design and started with a 2000+ HP engine, it first flew after jets were in service.

My original point in bringing it up was that creating something like an F8 (as an example of performance + range + agility) was hard, and that it came too late... I wasn't trying to belittle the Spitfire .

 

[tomo pauk]

My original point in bringing up the F8F was exactly that - striking such a balance as you see in that aircraft was possible but very hard, and in this example (among many others) came too late to play a role in the war.

It was hard, but it was achieved by 1943 on the Allied side, and even more so in 1944.

P-47 was a lot heavier (10,400 lbs vs 7,650 empty for F8), had a much larger wingspan (40' vs 35') and a much bigger / fatter fuselage. Somebody said it had a lower induced drag or something, I am not an engineer but i find it hard to believe that the P-47 had lower drag than an F8F.

Even if the P-47 have had a bit greater drag (possible, I don't have the exact numbers), it still flew with twice as much fuel in internal tanks when compared with F8F.
We can compare the drag, fuel carried and fuel mileage of F8F vs. P-51D and arrive at conclusion that F8F was capable for perhaps 50% of combat radius under the USAF ETO rules.

Fair points but this again seems to assume strategic bomber escort. A long ranged spitfire wouldn't necessarily be used that way ... I mean it could, but it would help the war effort a lot for example in places like North Africa, Malta, Darwin, New Guinea, China / Burma etc. This was the context from my point of view. Even with 150 gallons that F8F compares very well to a Spitfire or a Bf 109 in range, IMO, while having far more combat capability than say an A6M. If you are flying over the Pacific, through vast areas of China or Burma, or say, from Malta to North Africa or Sicily, you can probably use your drop tanks, though you may have to fly home right after an engagement.

Presumably if they had the F8F flying in say, 1943 the British could have put their own guns in it like they did with the Corsair.

Spitfire was carrying 100 US gals (84 imp gals); Mk.VII and VIII carried 144 US gals (120 imp gals). That is unless the rear fuselage tanks are installed. F8F carried 185 US gals. All internal fuel figures.
Having more fuel does not mean greater range if the new fighter has a thirsty engine and more drag than the legacy fighter. Allies have had the short-range fighters by thousands in 1942 and later, what they did not have were the long-range performers to match the Luftwaffe's best until late 1943.
Any post-war fighter will have far more combat capability than the Zero, there was a lot of wartime fighters capable for that.

Most fighter marks of the Spitfire were limited to around 500 miles range which relegated them to the status of point defense fighters or air superiority fighters deployed right at the front line. Something with the combat capabilities of a Spitfire, which were IMO a bit better than a P-51 depending on the specific marks, but with a 1,000 mile instead of 500 mile range, would have been very helpful for tactical escort, fighter bomber, and medium range air superiority missions.

See here, the 1500 mile range on Spitfire, 1700+ on Tempest, doc kindly provided by G Glider . Unfortunately, from late 1944 on:

 

[pbehn]

My original point in bringing it up was that creating something like an F8 (as an example of performance + range + agility) was hard, and that it came too late... I wasn't trying to belittle the Spitfire .

All designs are a compromise, you have to make more compromises with a 1000BHP engine than a 2000BHP engine. For the Spitfire as originally designed, take off run, rate of climb and speed were paramount but this was with a circa 1000BHP engine driving a fixed pitch prop that gave around 660 BHP on take off. tomo pauk posted the wing areas but the advantage of the Spitfire design over others such as the Hurricane was that the wings were thin, leaving little room for fuel. Maintaining air superiority over a battle front is difficult at range, the RAF struggled over Dunkerque while the allies shortened the range as soon as possibe by moving to Normandy, that 100 mile stretch of water is a problem especially if your aircraft is damaged.

 

[Wild_Bill_Kelso]

It was hard, but it was achieved by 1943 on the Allied side, and even more so in 1944.



Even if the P-47 have had a bit greater drag (possible, I don't have the exact numbers), it still flew with twice as much fuel in internal tanks when compared with F8F.
We can compare the drag, fuel carried and fuel mileage of F8F vs. P-51D and arrive at conclusion that F8F was capable for perhaps 50% of combat radius under the USAF ETO rules.

The thing about the P-47 is that it was a high altitude bird, (at least by design) being big and fat with huge wings etc. wasn't a disadvantage at 38,000 feet, to the contrary.

but the P-47 was in fact often used as a fighter bomber and for local air superiority over battlefields at much lower altitudes, and that is where it becomes a problem

I am certain the P-51D had better range than the F8F so no need for that. But I suspect the F8, like the Spitfire, probably had a slight edge over the P-51 in air combat, maybe more so since it was almost as fast.

Spitfire was carrying 100 US gals (84 imp gals); Mk.VII and VIII carried 144 US gals (120 imp gals). That is unless the rear fuselage tanks are installed. F8F carried 185 US gals. All internal fuel figures.
Having more fuel does not mean greater range if the new fighter has a thirsty engine and more drag than the legacy fighter. Allies have had the short-range fighters by thousands in 1942 and later, what they did not have were the long-range performers to match the Luftwaffe's best until late 1943.
Any post-war fighter will have far more combat capability than the Zero, there was a lot of wartime fighters capable for that.


See here, the 1500 mile range on Spitfire, 1700+ on Tempest, doc kindly provided by G Glider . Unfortunately, from late 1944 on:

View attachment 661912

Yes but isn't the above chart showing quite large external tanks, and if that the case doesn't it bring you back to the same problem the F8 ostensibly has with external tanks?

 

[Wild_Bill_Kelso]

All designs are a compromise, you have to make more compromises with a 1000BHP engine than a 2000BHP engine.

This is almost exactly the context of where I originally brought up the F8, upthread. That is just about what i said verbatim.

 

[tomo pauk]

The thing about the P-47 is that it was a high altitude bird, (at least by design) being big and fat with huge wings etc. wasn't a disadvantage at 38,000 feet, to the contrary.

but the P-47 was in fact often used as a fighter bomber and for local air superiority over battlefields at much lower altitudes, and that is where it becomes a problem

I am certain the P-51D had better range than the F8F so no need for that. But I suspect the F8, like the Spitfire, probably had a slight edge over the P-51 in air combat, maybe more so since it was almost as fast.

If we want to compare the fighters from 1945, the 420-425 mph F8F-1 is badly outpaced by 470-480 mph P-51H. Less firepower, too.
P-47 was indeed used as a fighter bomber. Once it wrestled the air superiority (in concert with other Allied aircraft) from the Axis air forces, and was a very good fighter bomber, with good payload, guns' firepower (double of what F8F-1 had), range and performance.
P-47 being a high-altitude bird was a feature, not a bug.

Yes but isn't the above chart showing quite large external tanks, and if that the case doesn't it bring you back to the same problem the F8 ostensibly has with external tanks?

90 imp gal (108 US gal) external tanks max, one per aircraft. Internal ('permanent') fuel was ~160 imp gals. Granted, some of the fuel in the rear tanks needed to be used up before entering the combat, just like on Mustangs with fuselage tanks.
Similar fuel system was used post-war on the Seafire 45 and 47, but with even more fuel, both internal and external.