A Critical Analysis of the RAF Air Superiority Campaign in India, Burma and Malaya in 1941-45

[RCAFson]

Interesting chart for a Spitfire V. Norwich to Berlin, 441 miles, escort range; London to Brest, Belarus, 1015 miles, reinforcing range, so must be a 90 IG slipper. Seafire III, navalised Spitfire V had a combat radius of 100 miles clean and 185 with a 60 IG torpedo tank. Whilst theoretically, with a 90 IG you could fly escort Norwich - Berlin, realistically you can't because you're flying too slow, you're flying over hostile territory, and finally manoeuvres are restricted with that big 90 IG slipper; it's just not going to happen. Longest Spitfire raid in Europe is SW England to La Palice, all over water in 1944, 370 miles in the Mk VII, so yes you could do that out and back at econ cruise perhaps with only a 45 IG slipper, and likewise you don't want the 90 IG slipper if at all possible because manoeuvres are restricted. The Australians did Darwin to East Timor return, 884 miles, only possible with a 90 IG slipper, but it's all over water, no other land anywhere in sight, unlike the La Palice raid. IIRC the LF XVI had an effective combat radius of 230 miles over Europe; I'm assuming this is using 66/75 IG rear fuselage and 45 IG slipper, but again over hostile territory.

I guess you missed this from a prior post, a Spitfire Mk XIV was pitted against a captured a FW190D and 109G:

About 20mph knocked off maximum speed...turning circle still within those of FW190 and Me109G... Conclusions. Even with the 90 gallon long range tank the Spitfire 14 can equal or outclass the FW190 (BMW801D) and Me109G in every respect...
Price, The Spitfire Story.

So the Mk XIV was flown to it's limits with the 90IG DT; the 30 and 45IG tanks were combat stressed as well. The Mk XIV airframe was basically just a MkVIII with a Griffon engine.

You keep forgetting that the 76IG rear fuselage tank was tested and found suitable for combat but only after about half the fuel was used, just like the Mustang. It would have increased internal fuel in a MK VII/VII to 200IG, and greatly increased the range so that the Timor raid could have been done on internal fuel alone. The Spitfire was just as capable of flying high and fast like the Mustang (albeit not quite as fast), because it had the same engine, if it could have similar internal fuel capacity, and the fact is that it could have had 90% of a Mustang's internal fuel capacity along with combat stressed SS slipper tanks, and it could have been modded to carry wing torpedo DTs, as the USAAF proved.

 

[Kevin J]

I guess you missed this from a prior post, a Spitfire Mk XIV was pitted against a captured a FW190D and 109G:

So the Mk XIV was flown to it's limits with the 90IG DT; the 30 and 45IG tanks were combat stressed as well. The Mk XIV airframe was basically just a MkVIII with a Griffon engine.

You keep forgetting that the 76IG rear fuselage tank was tested and found suitable for combat but only after about half the fuel was used, just like the Mustang. It would have increased internal fuel in a MK VII/VII to 200IG, and greatly increased the range so that the Timor raid could have been done on internal fuel alone. The Spitfire was just as capable of flying high and fast like the Mustang (albeit not quite as fast), because it had the same engine, if it could have similar internal fuel capacity, and the fact is that it could have had 90% of a Mustang's internal fuel capacity along with combat stressed SS slipper tanks, and it could have been modded to carry wing torpedo DTs, as the USAAF proved.

Exactly, it was a XIV with a 2000 hp engine and a 20 mph speed advantage with tank fitted, as opposed to a V with a 20/30 mph speed disadvantage when clean. It's a no brainer, the V will be shot from the skies, even the VII, VIII, IX & XVI will be 20 mph slower than their opponents with the 90 IG slipper fitted, so inferior just like the clean V maybe worse.

As for the underwing tanks, well maybe 45 IG only because the wings are able to only carry 250 not 500 lb bombs, and like the XVI, clip the wings when using the rear tanks. Then you have a fighter only good for less than 20/25 thou feet as the controls become sloppy above that height with the clipped wings. Not exactly ideal for an escort fighter.

 

[Mike Williams]

Spitfires used 90 gallon drop tanks for rodeos, sweeps and escort missions - into Germany from the UK when called for.

http://www.wwiiaircraftperformance.org/131-Brothers-7aug44.jpg

http://www.wwiiaircraftperformance.org/610-ORB-1sept44.jpg

http://www.wwiiaircraftperformance.org/350-ORB-11Sept44.jpg

http://www.wwiiaircraftperformance.org/130_Oprep-12Sept44.jpg

http://www.wwiiaircraftperformance.org/41-OpRep-17Sept44.jpg

 

[Mike Williams]

Spitfires used 90 gallon drop tanks for rodeos, sweeps and escort missions - into Germany from the UK when called for.

http://www.wwiiaircraftperformance.org/131-Brothers-7aug44.jpg

http://www.wwiiaircraftperformance.org/610-ORB-1sept44.jpg

http://www.wwiiaircraftperformance.org/350-ORB-11Sept44.jpg

http://www.wwiiaircraftperformance.org/130_Oprep-12Sept44.jpg

http://www.wwiiaircraftperformance.org/41-OpRep-17Sept44.jpg

Another interesting document showing Spitfire IX LF plus 25 lbs. boost operational with 90 gallon drop tanks:

http://www.wwiiaircraftperformance.org/150grade/1-squadron-oprep-27aug44.jpg

 

[Kevin J]

Another interesting document showing Spitfire IX LF plus 25 lbs. boost operational with 90 gallon drop tanks:

http://www.wwiiaircraftperformance.org/150grade/1-squadron-oprep-27aug44.jpg

But none of these had rear fuselage fuel tanks too.

 

[Kevin J]

But none of these had rear fuselage fuel tanks too.

And all would have had 130/150 fuel and almost 2000 hp, so that's mid 44 onwards.

 

[Schweik]

It's one thing to accidentally engage with your drop tank still on, because you didn't have time to drop them or because they were stuck etc., and survive it with a little luck and perhaps a situational advantage (spotting the enemy first, while above them for example), this also happened with P-51s and P-47s and P-38s etc., it was somewhat possible to fight anyway but it was not considered ideal. It is also true that with the fuel tanks on Allied fighters frequently got into trouble.

For example here is an example of a Spit Vc being lost in an engagement with Fw 190s over Nice, France on 8 Feb 1944 because the slipper tank caught fire. Six Spits engaged two Fw 190s and lost 3 in total, claiming one but apparently none were lost. Even the smaller slipper tanks also apparently contributed to accidents as seen here

The text reads: "To extend the VC's relatively short range, a cumbersome slipper tank could be fitted to the underside of the fighter..."

It is quite another thing, in my opinion, to select this option as a baseline. This would allow enemies to adapt and form tactics to exploit the weaknesses. Dropping 20 mph of speed, along with what would obviously also include degradation of climb, turning, dive speed and acceleration, could negate any combat advantages that a Spit VIII or IX had, and drop it back down into the realm of a Spit V... and we do remember what happened with Spit V and Fw 190s in 1942?

Top speed for a Spit V was around 360-370 mph, an early Fw 190 around 390 mph. A speed difference of 20-30 mph in other words, which was sufficient to successfully "boom and zoom" against the Spits. Spit IX had a top speed around 400 - 410 mph at altitude, Spit VIII up to 414, while the later model Fw 190As and D models had top speed of ~410-420 mph with boost, and late model Bf 109G up to 426 mph. Dropping that Spit IX down to 380 or 390 might put it right back into that vulnerable side of the envelope.


As for the feasibility of even flying with all the extra fuel, it's notable that for the ferry flight from Gibraltar to Malta (with 170 gal slipper tanks) the Spits had to have all but two machine guns removed and an extra oil tank added to the nose.

 

[RCAFson]

It's one thing to accidentally engage with your drop tank still on, because you didn't have time to drop them or because they were stuck etc., and survive it with a little luck and perhaps a situational advantage (spotting the enemy first, while above them for example), this also happened with P-51s and P-47s and P-38s etc., it was somewhat possible to fight anyway but it was not considered ideal. It is also true that with the fuel tanks on Allied fighters frequently got into trouble.

For example here is an example of a Spit Vc being lost in an engagement with Fw 190s over Nice, France on 8 Feb 1944 because the slipper tank caught fire. Six Spits engaged two Fw 190s and lost 3 in total, claiming one but apparently none were lost. Even the smaller slipper tanks also apparently contributed to accidents as seen here

The text reads: "To extend the VC's relatively short range, a cumbersome slipper tank could be fitted to the underside of the fighter..."

It is quite another thing, in my opinion, to select this option as a baseline. This would allow enemies to adapt and form tactics to exploit the weaknesses. Dropping 20 mph of speed, along with what would obviously also include degradation of climb, turning, dive speed and acceleration, could negate any combat advantages that a Spit VIII or IX had, and drop it back down into the realm of a Spit V... and we do remember what happened with Spit V and Fw 190s in 1942?

Top speed for a Spit V was around 360-370 mph, an early Fw 190 around 390 mph. A speed difference of 20-30 mph in other words, which was sufficient to successfully "boom and zoom" against the Spits. Spit IX had a top speed around 400 - 410 mph at altitude, Spit VIII up to 414, while the later model Fw 190As and D models had top speed of ~410-420 mph with boost, and late model Bf 109G up to 426 mph. Dropping that Spit IX down to 380 or 390 might put it right back into that vulnerable side of the envelope.


As for the feasibility of even flying with all the extra fuel, it's notable that for the ferry flight from Gibraltar to Malta (with 170 gal slipper tanks) the Spits had to have all but two machine guns removed and an extra oil tank added to the nose.

Yeah, the only Spitfire V ever shot down by an FW190 was due to carrying a 90IG slipper tank...LoL. C'mon, this is no longer a rational argument. It's exactly the same as claiming the Mustang or P-47 was useless because some were lost while carrying drop tanks.

The slipper tanks are drop tanks and can be released if needed, at up to 300mph IAS (= ~420mph TAS at 20Kft) and the idea for LR bomber escort is to use the 30 or 45IG DT along with wing mounted torpedo DTs rather than the 90IG tank. Although a Spitfire with a rear fuselage tank and a 90IG DT is still a potentially useful way to fly rendezvous escort missions over the portions of the bomber route that are nearer to the UK.

The 170IG slipper had 4x the drag of the 90IG slipper, and was very aerodynamically inefficient and meant strictly for ferry missions, OTOH the USAAF modded Spitfire IXs flew the Atlantic carrying full armament.

If the Spitfire is used as a LR escort and the Luftwaffe engages the escort rather than the bombers then the escort is serving it's purpose.

 

[Kevin J]

I guess you missed




Yeah, the only Spitfire V ever shot down by an FW190 was due to carrying a 90IG slipper tank...LoL. C'mon, this is no longer a rational argument. It's exactly the same as claiming the Mustang or P-47 was useless because some were lost while carrying drop tanks.

The slipper tanks are drop tanks and can be released if needed, at up to 300mph IAS (= ~420mph TAS at 20Kft) and the idea for LR bomber escort is to use the 30 or 45IG DT along with wing mounted torpedo DTs rather than the 90IG tank.

The 170IG slipper had 4x the drag of the 90IG slipper, and was very aerodynamically inefficient and meant strictly for ferry missions, OTOH the USAAF modded Spitfire IXs flew the Atlantic carrying full armament.

If the Spitfire is used as a LR escort and the Luftwaffe engages the escort rather than the bombers then the escort is serving it's purpose.

You missed, the bit about clipping the wings if using the fuselage tanks and reducing effective combat altitude to 20/25 thou feet, overstressing the airframe if using underwing tanks, keeping your speed up over hostile territory, safety in having large numbers of escorts, development life cycle, having lots of excess power available, to name but a few.

 

[RCAFson]

You missed, the bit about clipping the wings if using the fuselage tanks and reducing effective combat altitude to 20/25 thou feet, overstressing the airframe if using underwing tanks, keeping your speed up over hostile territory, safety in having large numbers of escorts, development life cycle, having lots of excess power available, to name but a few.

The use of clipped wings and rear fuselage tanks are independent of one another.

 

[Kevin J]

The use of clipped wings and rear fuselage tanks are independent of one another.

Not if carrying bombs, I imagine drop tanks would have same wrinkling effect on wings if fuselage tanks used.

 

[RCAFson]

Not if carrying bombs, I imagine drop tanks would have same wrinkling effect on wings if fuselage tanks used.

The wing torpedo tanks are not meant to be flown in dive bomber missions. The USAAF was able to fly two Spitfire 9s with rear fuselage tanks, and twin 62IG wing DTs and full armament across the Atlantic and the aircraft were then throughly tested in the UK with no problems due to wing load.

If you have a source stating that rear fuselage tanks could only be used on clipped wing Spitfires, I hope you can share it with us.

 

[Kevin J]

The wing torpedo tanks are not meant to be flown in dive bomber missions. The USAAF was able to fly two Spitfire 9s with rear fuselage tanks, and twin 62IG wing DTs and full armament across the Atlantic and the aircraft were then throughly tested in the UK with no problems due to wing load.

If you have a source stating that rear fuselage tanks could only be used on clipped wing Spitfires, I hope you can share it with us.

Someone's put the info up on here already, as for the American tests, it's all in the Spitfire Escort document about the airframe being overstressed. Look, even the Spitfire XVIII W

The wing torpedo tanks are not meant to be flown in dive bomber missions. The USAAF was able to fly two Spitfire 9s with rear fuselage tanks, and twin 62IG wing DTs and full armament across the Atlantic and the aircraft were then throughly tested in the UK with no problems due to wing load.

If you have a source stating that rear fuselage tanks could only be used on clipped wing Spitfires, I hope you can share it with us.

It's all on here, mate. Just go back reading everything again.

 

[RCAFson]

Someone's put the info up on here already, as for the American tests, it's all in the Spitfire Escort document about the airframe being overstressed. Look, even the Spitfire XVIII W


It's all on here, mate. Just go back reading everything again.

Sorry, I don't see it.

 

[Glider]

If I may interject here. The clipping of the wings was due to the impact of having the increased internal fuel tanks and a full bomb load as mentioned in my earlier message. Clearly the tanks were fitted before the clipping of the wings was found necessary. The evidence is as follows:-

 

[RCAFson]

If I may interject here. The clipping of the wings was due to the impact of having the increased internal fuel tanks and a full bomb load as mentioned in my earlier message. The evidence is as follows:-

View attachment 549505

Thanks. However, as I stated before, the wing DTs would not used for divebombing style sorties where a combination of high speed dives and high speed pullouts with bombs in place occur, as typically the Spitfire nose has to to be raised prior to bomb release, to ensure adequate prop clearance. The memo does seem to indicate, though, that Spitfires were being flown with the rear fuselage tanks in place and full of fuel.

Wing DTs would be released prior to engaging in combat and so the above is not relevant.

 

[Glider]

Thanks. However, as I stated before, the wing DTs would not used for divebombing style sorties where a combination of high speed dives and high speed pullouts with bombs in place occur, as typically the Spitfire nose has to to be raised prior to bomb release, to ensure adequate prop clearance. The memo does seem to indicate, though, that Spitfires were being flown with the rear fuselage tanks in place and full of fuel.

Wing DTs would be released prior to engaging in combat and so the above is not relevant.

Re you comment 'the wing DTs would not used for divebombing style sorties where a combination of high speed dives and high speed pullouts with bombs in place occur' I would have thought it was pretty blindingly obvious that you are not going to carry wing drop tanks with bombs in place. It's either bombs or drop tanks.

 

[RCAFson]

Re you comment 'the wing DTs would not used for divebombing style sorties where a combination of high speed dives and high speed pullouts with bombs in place occur' I would have thought it was pretty blindingly obvious that you are not going to carry wing drop tanks with bombs in place. It's either bombs or drop tanks.

I think it is obvious to you and me and that the wing DTs are meant to be released prior to combat, just as on the Mustang.

 

[Kevin J]

Re you comment 'the wing DTs would not used for divebombing style sorties where a combination of high speed dives and high speed pullouts with bombs in place occur' I would have thought it was pretty blindingly obvious that you are not going to carry wing drop tanks with bombs in place. It's either bombs or drop tanks.

I'm not convinced that you could put anything under the wings, either bombs or drop tanks, if you have a fuselage full of fuel and a bomb or slipper under the fuselage, without clipping the wings. The Brits rejected the American mod because the airframe was overstressed, to me that means the wings. I agree you're not going to dive bomb someone with drop tanks but that Spitfire wing was pretty thin. Let's be frank, you could put a 29 gal tank behind the pilot and a 170 gal slipper on so it can't be the fuselage with the overstressing problem.

 

[RCAFson]

I'm not convinced that you could put anything under the wings, either bombs or drop tanks, if you have a fuselage full of fuel and a bomb or slipper under the fuselage, without clipping the wings. The Brits rejected the American mod because the airframe was overstressed, to me that means the wings. I agree you're not going to dive bomb someone with drop tanks but that Spitfire wing was pretty thin.

I quoted the UK evaluation of the USAAF mods and the test flights were fine ( A Critical Analysis of the RAF Air Superiority Campaign in India, Burma and Malaya in 1941-45 ) We have to remember that the Mk IX airframe was basically the same as a Mk V, which in turn derived from the MK II. Whereas the MK VII/VIII airframe was reworked for greater strength.

But lets look at a long duration, high altitude, mission with a rear fuselage tank, two wing DTs and a 45IG DT.

TO on main tanks (15IG), switching to rear tank, to drain it to 1/2 full (-35IG). Switch to wing DTs, which are dropped when empty or contact is made with the enemy. At the point of contact, the Spitfire VIII has ~150IG in internal fuel and a 45IG DT and about is about ~400lb under the weight of the Spitfire loaded with 120IG fuel and 1000lb of bombs . (Mustang would be at about 160IG of internal fuel at this point) and about 1000lb under the weight of a Mk XIV with a full bomb load.