Allied AFs in 1943: realistic options for long range fighters?

[tomo pauk]

The guns are depicted in the post #47. Cannon remains in the post, accompanied with a HMG. In the same post:

Not quite as big a fuel quantity as at the PR versions, but still useful.

So, not 2 x 66 imp gals, but certainly more than 2 x 12,5 i,mp gals as in Spit VII/VIII/XIV wings.

When the military planers requires more range for a plane, this is a technical challenge to the engineers and when the engineers tell them that this is not possible for that reason I believe the engineer of this time.

I'm sure that any modification as a challenge for the engineer, more so since the mistake(s) engineer(s) made can cost lives. We can look at the planes whose engineers said 'yes, can do' to a request for more internal fuel, like P-51, P-47, P-38, Spitfire, Tempest, Yak-9D/DD etc.

 

[Shortround6]

Please note the words "integral fuel tank" which means the fuel tank formed a structural component of the wing and could not be removed ( or removed easily) for repair or replacement. It would be interesting to know if the "integral" tanks were self sealing or not.

 

[tomo pauk]

As said before, any good data is welcomed

 

[FLYBOYJ]

Please note the words "integral fuel tank" which means the fuel tank formed a structural component of the wing and could not be removed ( or removed easily) for repair or replacement. It would be interesting to know if the "integral" tanks were self sealing or not.

Depends on the aircraft - For example, I believe the F4U had a center "integral" tank that was not self sealing.

 

[Edgar Brooks]

Like it, or lump it (and tempers are appearing to fray,) you cannot remove 11 wing ribs from the leading edge box without seriously weakening the structure; the P.R. aircraft (even though drawings depict the box as an empty space) retained the ribs, in fact they were converted, in places, to solid "baffles," with non-return valves fitted to them, so that, as the fuel was used, it ran towards the wings' centre section, and stayed there.
There was no way that the Air Ministry would remove the outer pair of .303" guns, simply because they preferred their higher rate of fire (and double the number) to the slower-firing .5". Now, you can argue up, down, and sideways, about the reasoning, but it won't alter the fact that it was their decision, and even an officer as senior as Leigh-Mallory couldn't shift them. It was early 1944 before the .5" was seriously considered, and that was due to the arrival of the gyro gunsight, which meant that pilots actually began to hit what they were aiming at. Even then, the wings still contained the tubes, for the outer guns, and it would have needed some major work to remove them, and beef up the structure (and you, again, come back to the need to remove the structural ribs, which was never going to happen.)

 

[tomo pauk]

Like it, or lump it (and tempers are appearing to fray,)

I'm rather mild tempered, considering I'm from Dalmatia

you cannot remove 11 wing ribs from the leading edge box without seriously weakening the structure; the P.R. aircraft (even though drawings depict the box as an empty space) retained the ribs, in fact they were converted, in places, to solid "baffles," with non-return valves fitted to them, so that, as the fuel was used, it ran towards the wings' centre section, and stayed there.

Thanks for the fine details about the wing LE tanks of the PR birds.
So we will retain the ribs and go with integral leading edge tank.

There was no way that the Air Ministry would remove the outer pair of .303" guns, simply because they preferred their higher rate of fire (and double the number) to the slower-firing .5". Now, you can argue up, down, and sideways, about the reasoning, but it won't alter the fact that it was their decision, and even an officer as senior as Leigh-Mallory couldn't shift them. It was early 1944 before the .5" was seriously considered, and that was due to the arrival of the gyro gunsight, which meant that pilots actually began to hit what they were aiming at. Even then, the wings still contained the tubes, for the outer guns, and it would have needed some major work to remove them, and beef up the structure (and you, again, come back to the need to remove the structural ribs, which was never going to happen.)

So the RAF pilots can actually hit something with 20mm, yet they would be unable to hit anything with .50? The .50 is here a mere back up augmentation for the 20mm anyway. The .50 can actually do some damage after it pierces the aircraft skinning, like puncture the fuel tank, unlike the LMG bullet.
As to a 'major work to remove tubes for LMG barrels', now that does not seem like something undoable for the people flying jet aircraft in early 1940s? Why not simply leave the barrels inside, or what ever the fix was for the PR birds; same applied again for the structural ribs? What part of the structure need to be beefed up because we're removing the tubes anyway?

 

[Edgar Brooks]

I'm rather mild tempered, considering I'm from Dalmatia.

Some of the gentlest, most even-tempered dogs I've ever known come from there.

So the RAF pilots can actually hit something with 20mm, yet they would be unable to hit anything with .50? The .50 is here a mere back up augmentation for the 20mm anyway. The .50 can actually do some damage after it pierces the aircraft skinning, like puncture the fuel tank, unlike the LMG bullet.

This is what I feared; I can only pass on what the Air Ministry's reasoning was, and why. Tests found that the .5" was no better, at penetration, than the .303", in a deflection shot of, on average, 2 seconds' duration, so 2 seconds' worth of 4 x .303" was more likely to kill enemy aircrew than 2 seconds of 2 x .5". Time, and time again, I've passed on this information, which usually draws a response of "I don't believe it." Sorry, but I can't change 75-year-old history, simply because it isn't liked.
Just because the war developed into a fighter-v-fighter conflict, this was not something on which the U.K. "management" could rely, until very late in the war; they always had to consider the possiblity of the Battle of Britain being restarted, especially if Russia fell, which seemed likely at first. With that in mind, range was very much a secondary consideration to destroying the expected new crop of larger, more heavily-armoured German bombers, which was why firepower took precedence over range. The Spitfire VIII was designed with 4 x 20mm + 4 x .303" in mind, and the 21 was always a 4 x 20mm only.

As to a 'major work to remove tubes for LMG barrels', now that does not seem like something undoable for the people flying jet aircraft in early 1940s? Why not simply leave the barrels inside, or what ever the fix was for the PR birds; same applied again for the structural ribs? What part of the structure need to be beefed up because we're removing the tubes anyway?

You can't remove the gun tubes if you're planning to use them, and that was the plan until 1944; leave them in, and leave in the ribs (which you have to do, to keep the wing's strength,) and there's nowhere for the fuel tanks to go. Each rib is a curved strip, top and bottom, with two "V" constructions (forming a "W") between them, imparting stiffening. There was no "fix" for the P.R. aircraft; they used a completely new type of "D" box, with different ribs and completely fuel-sealed (take out gun tubes, and you're left with big holes in the spars and leading edges, which need plating over, and yet more fuel-sealing.)

 

[tomo pauk]

Here is what Hawker did - Typhoon's front part of the wing, with ribs, while having the fuel tank inside. 40 gals actually, not 35.

 

[Shortround6]

Uh, Tomo, if the integral tanks are NOT self sealing ( and trying to apply self sealing materials to a tank as described by Edger Brooks is most difficult. Gotten around in some aircraft by fitting self sealing fuel bladders/cells into such spaces at the cost of weight and volume/capacity) then even LMG bullets can pierce the tank and cause a loss of fuel and range/radius even if nothing worse.

US Navy practice was to count ONLY the capacity of protected tanks when figuring COMBAT radius. Which is one reason the unprotected wing tanks on the Corsair were replaced by drop tanks. A number of aircraft used integral tanks, many of them were not self sealing. The PBY Catalina used integral tanks that could be fitted with protected fuel cells inside the tanks for a large drop in capacity. The Buffalo started with integral tanks, one of which was seal off and 3 other protected tanks fitted to restore fuel capacity.
Perhaps there were protected integral tanks in WW II, I don't know but I do know that the more little (or big) tanks you stick in one airplane and the more complicated the fuel system ( a P-51 pilot only had to manage 5 tanks at the most, late Corsairs 3 tanks?) ) the more likely the pilot is to make a mistake and crash due to selecting the wrong tank or failing to restart the engine after selecting a wrong tank. Lots of planes crash with stopped engines even though one or more fuel tanks still contain fuel.

If you can get 96 imp gallons in the fuselage tanks, 27 imp gallons in the wing tanks and even 15imp gallons in a rear fuselage tank to be useable in combat you have 173 US gallons which is darn near what a Mustang had without the rear tank. What you also have is a higher drag airframe than the Mustang which means you won't go as far on the same fuel.
I don't know if the 15imp gallons in the rear is a feasible amount to use in combat but it is about 20% of what was fitted in some planes but NOT used in combat ?? It may give 10-20% less radius than a wing tank only Mustang without all the trouble of redoing the wings you want to do.

At some point you cut your losses and just design a new plane rather than hammer square pegs into round holes.

 

[Edgar Brooks]

The Spitfire was designed to a 1934 Air Ministry specification F.37/34, which specified the fuel load should be 94 gallons, which is what Mitchell did; the Typhoon was designed to a 1937 specification F.18/37, which called for a load of 200 gallons. If Mitchell had planned for a load of 200 gallons, the Spitfire would never have been built; ignore the Air Ministry's requirements at your peril.

 

[bobbysocks]

as long as that section of the leading edge isnt used for routing hydraulic lines , static/pitot lines, electrical or other components, gun cameras, etc...you are fine as you are with the tempest but other ac may make use of this area.

 

[tomo pauk]

...
This is what I feared; I can only pass on what the Air Ministry's reasoning was, and why. Tests found that the .5" was no better, at penetration, than the .303", in a deflection shot of, on average, 2 seconds' duration, so 2 seconds' worth of 4 x .303" was more likely to kill enemy aircrew than 2 seconds of 2 x .5". Time, and time again, I've passed on this information, which usually draws a response of "I don't believe it." Sorry, but I can't change 75-year-old history, simply because it isn't liked.

It is not something I like or dislike. The .50 bullets from pre-war era were of far lower capabilities than mid-war APIs (US engineers copying Soviet bullets?).

Just because the war developed into a fighter-v-fighter conflict, this was not something on which the U.K. "management" could rely, until very late in the war; they always had to consider the possiblity of the Battle of Britain being restarted, especially if Russia fell, which seemed likely at first. With that in mind, range was very much a secondary consideration to destroying the expected new crop of larger, more heavily-armoured German bombers, which was why firepower took precedence over range. The Spitfire VIII was designed with 4 x 20mm + 4 x .303" in mind, and the 21 was always a 4 x 20mm only.

You can note that I don't propose the removal/change of the 20 mm.
RAF went for extended range for their Spitfires (fighter versions) with Mk.VII on, and was using drop tanks early in the war, so it's clear they wanted/needed more range. The Spitfire with 150 IG instead of 120 IG should not be a huge task, neither for the design production, nor for the Merlin/Griffon.
As for what UK management could rely: seem like they considered even in 1943/44 that Russia is going to fail, after seeing the fuel tankages of the Tempest and late Spitfires.

You can't remove the gun tubes if you're planning to use them, and that was the plan until 1944; leave them in, and leave in the ribs (which you have to do, to keep the wing's strength,) and there's nowhere for the fuel tanks to go. Each rib is a curved strip, top and bottom, with two "V" constructions (forming a "W") between them, imparting stiffening. There was no "fix" for the P.R. aircraft; they used a completely new type of "D" box, with different ribs and completely fuel-sealed (take out gun tubes, and you're left with big holes in the spars and leading edges, which need plating over, and yet more fuel-sealing.)

Several variants to consider, then. 1st can use modified PR wing, arming it, with fuel tank consisting of two halfs - one outboard, other inboard of the armament, connected with a tube non - return valve. We lose some of the volume in process, so it's maybe 2 x 50 gals, not 2 x 66. So the plane has 195 IG of fuel
2nd variant: in the place once occupied with outboard LMGs and their ammo (area between the spars), install the fuel tanks. Say, 2 x 20 IG? The plane has 160 IG with VII/VIII/XIV wing - not bad either

 

[tomo pauk]

Uh, Tomo, if the integral tanks are NOT self sealing ( and trying to apply self sealing materials to a tank as described by Edger Brooks is most difficult. Gotten around in some aircraft by fitting self sealing fuel bladders/cells into such spaces at the cost of weight and volume/capacity) then even LMG bullets can pierce the tank and cause a loss of fuel and range/radius even if nothing worse.

There is no doubt that LE self-sealing tanks in a thin wing are not ideal thing. It does cost weight complexity. It also allows, once installed, to prosecute the war at enemy's air space.

US Navy practice was to count ONLY the capacity of protected tanks when figuring COMBAT radius. Which is one reason the unprotected wing tanks on the Corsair were replaced by drop tanks. A number of aircraft used integral tanks, many of them were not self sealing. The PBY Catalina used integral tanks that could be fitted with protected fuel cells inside the tanks for a large drop in capacity. The Buffalo started with integral tanks, one of which was seal off and 3 other protected tanks fitted to restore fuel capacity.

Fair points. Typhoon and P-47N featuring self-sealing tanks in leading edge?

Perhaps there were protected integral tanks in WW II, I don't know but I do know that the more little (or big) tanks you stick in one airplane and the more complicated the fuel system ( a P-51 pilot only had to manage 5 tanks at the most, late Corsairs 3 tanks?) ) the more likely the pilot is to make a mistake and crash due to selecting the wrong tank or failing to restart the engine after selecting a wrong tank. Lots of planes crash with stopped engines even though one or more fuel tanks still contain fuel.

Seafire 46 went with 7 (seven) internal fuel tanks, plus 3 drop tanks. Quite a number, I suppose. So I'd like to see 2 fuselage tanks, and 2 pairs of inter-connected wing tanks, and a fuselage drop tank.

If you can get 96 imp gallons in the fuselage tanks, 27 imp gallons in the wing tanks and even 15imp gallons in a rear fuselage tank to be useable in combat you have 173 US gallons which is darn near what a Mustang had without the rear tank. What you also have is a higher drag airframe than the Mustang which means you won't go as far on the same fuel.
I don't know if the 15imp gallons in the rear is a feasible amount to use in combat but it is about 20% of what was fitted in some planes but NOT used in combat ?? It may give 10-20% less radius than a wing tank only Mustang without all the trouble of redoing the wings you want to do.

I've proposed a Mk.VIII with rear fuselage tank a page or two before

At some point you cut your losses and just design a new plane rather than hammer square pegs into round holes.

Of course the new designs need to be issued. The point in this thread is to come out with a feasible modification for the 1st half of 1943, starting date being September 1942.

 

[Edgar Brooks]

as long as that section of the leading edge isnt used for routing hydraulic lines , static/pitot lines, electrical or other components, gun cameras, etc...you are fine as you are with the tempest but other ac may make use of this area.

Up to, and including, the Mk.VI, the leading edge was used to carry hot air pipes out to the outer pair of .303" (and, however much you twist and turn, the A.M. are not going to remove those guns until they think it's worthwhile.) That did not happen until 1944.

Several variants to consider, then. 1st can use modified PR wing, arming it, with fuel tank consisting of two halfs - one outboard, other inboard of the armament, connected with a tube non - return valve. We lose some of the volume in process, so it's maybe 2 x 50 gals, not 2 x 66. So the plane has 195 IG of fuel
2nd variant: in the place once occupied with outboard LMGs and their ammo (area between the spars), install the fuel tanks. Say, 2 x 20 IG? The plane has 160 IG with VII/VIII/XIV wing - not bad either

50 gallons = 350+ lbs; when the Spitfire wing was strenghened enough to carry a 250lb bomb under each wing, the tips still had to be clipped, in order to stand the strain, the pilots were banned from making any sort of aerobatic manouevre, and 11 Group's C.O. flatly refused to have clipped-wing Spitfires acting as escort, since their rate of climb and operational height were so adversely affected. I somehow doubt that pilots, told that they couldn't get involved in any form of combat, before their wing tanks were empty, would not have been overly impressed.
The Seafire 40-series, and the Spitfire 20-series, had entirely new, strengthened wings, with different wingspars, and ailerons which did not tend to make the wing twist, when operated. This meant that they could carry more fuel. Due to aerodynamic troubles, the 21 was passed for service only in 1945, and the Seafires did not see service, during the war, at all.

As for what UK management could rely: seem like they considered even in 1943/44 that Russia is going to fail, after seeing the fuel tankages of the Tempest and late Spitfires.

It's just as well they did, otherwise the V1s would have done far more damage than they did (and that was bad enough.)

 

[CobberKane]

I believe that a number of Soviet aircraft reduced the chance of fire by routing the inert engine exhaust gasses through the space left as the petrol was consumed. Seems like a pretty simple expedient - did any other Allied or Axis aircraft use the same idea?

 

[tomo pauk]

as long as that section of the leading edge isnt used for routing hydraulic lines , static/pitot lines, electrical or other components, gun cameras, etc...you are fine as you are with the tempest but other ac may make use of this area.

Up to, and including, the Mk.VI, the leading edge was used to carry hot air pipes out to the outer pair of .303" (and, however much you twist and turn, the A.M. are not going to remove those guns until they think it's worthwhile.) That did not happen until 1944.

The guns in later versions were provided with heating via tubes going aft the guns.

50 gallons = 350+ lbs; when the Spitfire wing was strenghened enough to carry a 250lb bomb under each wing, the tips still had to be clipped, in order to stand the strain, the pilots were banned from making any sort of aerobatic manouevre, and 11 Group's C.O. flatly refused to have clipped-wing Spitfires acting as escort, since their rate of climb and operational height were so adversely affected. I somehow doubt that pilots, told that they couldn't get involved in any form of combat, before their wing tanks were empty, would not have been overly impressed.
The Seafire 40-series, and the Spitfire 20-series, had entirely new, strengthened wings, with different wingspars, and ailerons which did not tend to make the wing twist, when operated. This meant that they could carry more fuel. Due to aerodynamic troubles, the 21 was passed for service only in 1945, and the Seafires did not see service, during the war, at all.

Thanks for the details.
You can note the emoticon ( 8) ) after those 195 gals are mentioned. Those 2 x 50 gals of wing fuel serve just for illustrative purposes, since even adding another 30 gals (2 x 15) for the 120 gal Spitfires can make them almost as fine long range fighters as the Merlin Mustangs (without fuselage tanks) were.

It's just as well they did, otherwise the V1s would have done far more damage than they did (and that was bad enough.)

Having more internal fuel does not imply that a plane, once able to catch a V1, is unable to do so anymore. It should be able to make two kills, before running out of fuel, instead of one. Maybe the accomplishments of Allied bombers achieved in 1943 (made possible now, since we have plenty of long range fighters in that year, like 150 imp gal Spitfires) can kill the V1/V2 in their nests?

 

[tomo pauk]

In the Ethell's book about the P-51, there is an tidbit about A-36 acting as an escort for the B-24s and B-17s attacking Naples. Unsurprisingly, the engine's supercharger (tailored for low level bomber's duties) making the job a difficult one. The AHT mentions the A-36 (along P-38 and Spitfire) as the cover for the invasion of Italy, Aug 1943. So there is another plane that can free more P-38s from the MTO to the ETO - the P-51/51A. The escort altitudes were not that high as in ETO, and many times the charges were medium bombers, themselves not flying at high altitudes. The AAA threat was also lower, with many targets being near the coastline themselves.
The P-51 was not able to carry drop tanks, the 'yardstick' range being some 1000 miles (combat range of some 300-350 miles?), and the engine is well suited for operations from SL up to 15000 ft. The P-51A can carry drop tanks (2 x 75 gals were the usual ones), and the engine provides good performance from SL up to 20000 ft. With 2 x 75 gals external, the yardstick range is 1500 miles - 500 miles of combat range?
Historically, the 1st recipients of the P-51A were RAF (named Mustang II; 50 planes in June 1943) and the 311th FB group in, well, India.

 

[Vincenzo]

V-1710-81 FTH is 14,600 maybe too much 20,000

 

[tomo pauk]

At 20000 ft, with wing racks (those cost 12 mph, but are a necessity for the long range) P-51A makes ~390 mph.

 

[Edgar Brooks]

The guns in later versions were provided with heating via tubes going aft the guns.

Only the cannon and .5" in the E wing; earlier C wings, on the VII, VIII, IX XIV, had the heating tubes for the outer guns, having passed through the rear of the cannon bays, routed the same way as before, with the tubes coming from in front.

Having more internal fuel does not imply that a plane, once able to catch a V1, is unable to do so anymoreIt should be able to make two kills, before running out of fuel, instead of one. .

Always assuming that the Germans oblige by sending the V1s in batches, which they often didn't.

Maybe the accomplishments of Allied bombers achieved in 1943 (made possible now, since we have plenty of long range fighters in that year, like 150 imp gal Spitfires) can kill the V1/V2 in their nests?

Even those hidden in caves? Judging by the results at Watten, Wizernes, Siracourt, Marquise/Mimoyecques, and Rilly-la-Montagne, the bombers did a fairly good job, anyway, and not many of the ski-sites got away without a pounding (from the USAAF the RAF.)
And the Germans had a charming habit of firing the V2s from among the homes of Dutch civilians, so heavy bombers were banned (the only time mediums were used, it turned into a disaster,) and the hunting was done by the Spitfire XVIs with 1 x 500lb + 2 x 250lb bombs (usually,) but that was not possible until 1945.