1000-1200 HP: long range fighter vs. interceptor?

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Everyone seems to have forgot about the incomparable Fairey Fulmar, which was a purpose built SE escort fighter.

Its a good point. A Fulmar reduced in size with a single pilot and a couple of drop tanks could have been useful
 
Two things appear here. 1st, Germany was not, in 1939, dependent on engines that would offer only 880 HP for take off, they have ~1100 PS engines (take off power); they also have constant speed props in good numbers even then. 2nd, the fact that BC will not give away the Merlin X engines does not nothing to prove that a Spitfire with such engine would be unable to take off with, say, drop tank attached, it proves that BC have had a 1st call on these - no more, no less.

Which is why, in part, I try to use the MK II Spitfire as a base. The Problem with the MK is that the addition of the constant speed prop, while it helps a lot added around 200lbs, armor and self-sealing tanks upped the weight some more and new windscreens, canopies, and radio gear cut the performance of the MK II to near what the MK I had, without adding hundreds of pounds of internal fuel.



The Spitfire V was able to take off with 170 imp gal slipper tank, and 29 gal fuel aft the pilot. That would be over 1430 lbs of additional fuel alone, at 1185 HP for take off. Seems that Spit II would have no problems to take off with, say, 1000 lbs of additional fuel?

In some cases they accomplished this by pulling not only the ammo but the guns or a majority of the guns. NOT a good solution for an escort fighter. The Plane, like other planes could not fight with the tank/s attached. And that is part of the problem with the escort fighter, it needs more internal fuel, not just drop tanks.

I don't have the fuel consumption for the earlier engines but a Merlin 45 burns 2 1/2 gallons a minute at 16lbs boost and about 1 1/2 gallons a minute at 9lbs boost. SO you need about 32 gallons for combat, 10 gallons for start, warm up and take-off before switching to drop tanks, 10 gallons reserve (20 minutes flying time) for finding the home airfield leaving you with about 35 gallons for the "flight" home. A Spitfire V was good for about 263 mph true at 20,000ft burning 36 imp gallons an hour at 2200rpm and -1 3/4lbs 'boost' (yes, negative boost) 7.3miles per imp gallon
It doesn't matter what kind of drop tanks you use, you need more internal fuel, it is 256 miles from Cologne to Canterbury and with just 20 minutes reserve you may just see a lot of planes ditch in the Channel. No allowance made for prevailing winds out of the west.
Increasing flight speed to 300mph at 20,000ft kicks the fuel burn to 46imp gallons an hour (6.5 mpg) and any higher speed just makes it worse.




Agreed with pretty much what you said, quirk is to build a plane with modest power to perform well on longer ranges. IMO, far more depended on current doctrines mantras, than on capabilities of that or this design bureau/manufacturer. As seen with Zero, Ki-61 and Regianne fighters (leaving the P-51 aside).

The Ki-61s extra range is debatable as is it's performance. We know how the Zero got it's range and part of the "solution" is unacceptable to western nations. another part is that not only was the construction "weak" from taking damage but it's construction limited it's dive speed. Later versions just used heavier wing skinning (heavier structure) to increase the max permitted dive speed.



If there were a will to attach a drop tank at Bf-109E, it would've made the BoB far more a challenge to the RAF; the 'proper' drop tank installation on P-47 in 1943 would see an earlier/bigger attrition of the LW in the ETO.
Very true but the biggest drop tank in the world won't see a 109 to get to Belfast. The 109 faced a similar problem, it needs around 50 gallons (give or take) for initial, take-off, combat and reserve leaving around 40 gals or less for the trip home. Putting on a drop tank of much more than 40 gallons doesn't buy you much. The standard Luftwaffe 300 liter tank allowed for forming up, climb to altitude and probably as much penetration distance as the 109 could get itself back out of once the tank was gone. An extra 100 liters inside would be worth a lot more than extra fuel outside.

While the escort fighter doesn't need bomber destroying armament it needs enough guns to be effective and enough ammo so that it isn't sitting there with fuel but no ammo after a few bursts.


If the Spitfire was outfitted with Merlin XX, it would've been able to take off from a smaller carrier with greater load of fuel, and make it to Malta, but this you have covered.

In some of these "special ops" tricks were used that would NOT be used in every day operations. The Spitfires (MK Vs with Merlin 45 engines) would be allowed 12lbs or more boost for take-off while wooden wedges were used to prop open the flaps. Using 'combat' power settings that required extra maintenance for 'routine' missions is NOT the way to go.
 
Which is why, in part, I try to use the MK II Spitfire as a base. The Problem with the MK is that the addition of the constant speed prop, while it helps a lot added around 200lbs, armor and self-sealing tanks upped the weight some more and new windscreens, canopies, and radio gear cut the performance of the MK II to near what the MK I had, without adding hundreds of pounds of internal fuel.

Fair points.
The 20-30 imp gals of added internal fuel would've added 144-216 lbs, plus whatever the tanks are weighting - another 50-60 lbs? Total ~200-280 lbs, on 6170 lbs for the Spit II ready for combat, or 3.5-4% increase in weight.

In some cases they accomplished this by pulling not only the ammo but the guns or a majority of the guns. NOT a good solution for an escort fighter. The Plane, like other planes could not fight with the tank/s attached. And that is part of the problem with the escort fighter, it needs more internal fuel, not just drop tanks.

The slipper tank was droppable. An 'L' shaped tank, under-aft of pilot's seat, should be better to balancing out the CoG (something like mini version of what Bf-109 used). Or a small tank, fully under pilot.
A Spitfire II with 80-100 IMP gals of fuel in drop tank already has circa twice the fuel than it was carried internally, and, by the European standards of 1940, it could be called long range. The 40 imp gal drop tank ('over-load tank') seem like standard, though.

I don't have the fuel consumption for the earlier engines but a Merlin 45 burns 2 1/2 gallons a minute at 16lbs boost and about 1 1/2 gallons a minute at 9lbs boost. SO you need about 32 gallons for combat, 10 gallons for start, warm up and take-off before switching to drop tanks, 10 gallons reserve (20 minutes flying time) for finding the home airfield leaving you with about 35 gallons for the "flight" home. A Spitfire V was good for about 263 mph true at 20,000ft burning 36 imp gallons an hour at 2200rpm and -1 3/4lbs 'boost' (yes, negative boost) 7.3miles per imp gallon

Thanks for the effort to find crunch the numbers.
The extra internal fuel of just 18 imp gals would've increased 'flight home range' for some 130 miles then, or up to 390.

It doesn't matter what kind of drop tanks you use, you need more internal fuel, it is 256 miles from Cologne to Canterbury and with just 20 minutes reserve you may just see a lot of planes ditch in the Channel. No allowance made for prevailing winds out of the west.
Increasing flight speed to 300mph at 20,000ft kicks the fuel burn to 46imp gallons an hour (6.5 mpg) and any higher speed just makes it worse.

Fair points, extra internal fuel is what would make difference, provided the CoG is not too much affected.

The Ki-61s extra range is debatable as is it's performance.

Not sure from where this come from. The 'Bunrin do' book about the Ki-61 states internal fuel as being either 650 or 750 liters (143 or 165 imp gals), this document pretty much agrees with that (199 US gals). With 2 x 200 L (= 105 imp gals) of external fuel the range was phenomenal. The speed listed at the document is 580 km/h, 361 mph, again the book agrees.

We know how the Zero got it's range and part of the "solution" is unacceptable to western nations. another part is that not only was the construction "weak" from taking damage but it's construction limited it's dive speed. Later versions just used heavier wing skinning (heavier structure) to increase the max permitted dive speed.

Zero have had it's weaknesses, not just the ones you've mentioned. The good protection was not a wide spread thing in most of pre-1941 fighters, though.

Very true but the biggest drop tank in the world won't see a 109 to get to Belfast. The 109 faced a similar problem, it needs around 50 gallons (give or take) for initial, take-off, combat and reserve leaving around 40 gals or less for the trip home. Putting on a drop tank of much more than 40 gallons doesn't buy you much. The standard Luftwaffe 300 liter tank allowed for forming up, climb to altitude and probably as much penetration distance as the 109 could get itself back out of once the tank was gone. An extra 100 liters inside would be worth a lot more than extra fuel outside.

I'm sure that nobody was expecting for a 109 to be turned into Mustang, once drop tanks are fitted. There were plenty of closer targets, than N. Ireland, where LW bombers would've welcomed escort, though.
Interestingly enough, the 109 was well able to receive a 'consumable' tank (GM-1, 350 kg? or MW-50 tank) behind it's fuel tank without much trouble, CoG wise - one wonders whether there was a potential for LR 109?

While the escort fighter doesn't need bomber destroying armament it needs enough guns to be effective and enough ammo so that it isn't sitting there with fuel but no ammo after a few bursts.

Agreed. The homogeneous, belt fed armament, like the 8 LMG battery found in Spitfires, seems far more suited than what 109Es carried.

In some of these "special ops" tricks were used that would NOT be used in every day operations. The Spitfires (MK Vs with Merlin 45 engines) would be allowed 12lbs or more boost for take-off while wooden wedges were used to prop open the flaps. Using 'combat' power settings that required extra maintenance for 'routine' missions is NOT the way to go.

By the time Merlin XII and XX arrived, the 100 oct fuel and associated +12 lbs boost were well known commodity in the RAF (along with maintenance needed), unlike the time when Merlin III and X were arriving in combat units. I'm not suggesting running those earlier engines at higher boost where the manuals don't say the same.
 
Interestingly enough, the 109 was well able to receive a 'consumable' tank (GM-1, 350 kg? or MW-50 tank) behind it's fuel tank without much trouble.

Eventually, but that's not the 1940 system in which nitrous oxide was stored in several pressure flasks behind the cockpit (and injected in gaseous form).
It was a later system that used the 85 litre insulated tank to store cooled nitrous oxide. I can't remember when the change was made. I think it came in with the G series but wouldn't bet my house on it.
Cheers
Steve
 
Of course there are many good reasons why the RAF were at a disadvantage but, before the 109's arrived the Hurricanes more than held their own, after the 109's left again the Hurricanes did well, when the 109F's arrived then it was game over for the Hurricane. However to go four months in combat and not lose a single aircraft on operations is by any standards a notable achievement. There is no doubt that over Malta for whatever the reason, the 109E dominated the skies.

The majority of the german claims were supported by RAF records, not all of them but the majority. 22nd March the Luftwaffe claimed 7 Hurricanes and the RAF admitted losing five, no 109's were lost. 28th March the Germans claimed two, in reality one was shot down and another crash landed. 11 April the Germans claimed three and the RAF lost two with two more crash landed no 109's lost. You get the picture.
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The 109Es shot down 20-30 Hurricanes over a 4 month period ( approx one-two days production), or 5-6/month - Hardly dominating or crippling losses if the Hurricanes had been reinforced adequately during those 4 months. Hurricanes also engaged other Axis aircraft, including other Axis SE fighters so not all Hurricane losses were to 109s. Surprisingly the Hurricane had a better kill loss ratio against the 109F than against the 109E which points to the fact that 7/JG 26 was using hit and run tactics, which they could get away with because of the huge overall Axis numerical advantage. If 7/JG 26 was the only axis fighter unit involved it would not have been able to employ the same tactics and would have inevitably suffered much higher losses while inflicting fewer kills.

Reviewing past posts, it seems that 7/JG 26 was credit with about 27 Hurricane kills by Shores and Co. during the 4 month period in early 1941.
 
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Fair points.
The 20-30 imp gals of added internal fuel would've added 144-216 lbs, plus whatever the tanks are weighting - another 50-60 lbs? Total ~200-280 lbs, on 6170 lbs for the Spit II ready for combat, or 3.5-4% increase in weight.

go back to post #22 where I gave the climb rates for a standard MK II and a MK II with a single 40 gallon under wing tank. Also please figure that a Merlin running at 2650rpm and 6lbs boost was burning 70 gal an hour and 3000rpm and 9lbs was 88 gallons an hour. What is was at 2850rpm and 9lbs??? If the plane with 40 extra gallons takes 20 min to get to 30,000ft it has burned 27 or more gallons just getting there ( not including take-off). It is still ahead of the standard capacity fighter on fuel though.
The standard fighter can climb at 995fpm at whatever weight it is with the fuel left on board. The plane with the extra external tank is climbing at 545fpm. About 55% of the climb rate. this compares to the 2,000ft rate of climb which had the heavier fighter climbing at 76% the rate of the lighter fighter.

This is part of the problem with the low powered escort fighter plan. At high altitudes ( over 20,000ft) even somewhat small changes in weight can have big changes in rates of climb. Putting the fuel inside and saving on drag will help some but how much of a loss in climb (excess power) can you take? it was this that screwed up the 109 gun boats. Loss of speed was not much, but the loss of 1.5-2meters/sec in climb carried through all the way up. The difference at sea level may have been under 10%, over 25,000ft the difference in climb percentage wise was much greater.

Thanks for the effort to find crunch the numbers.
The extra internal fuel of just 18 imp gals would've increased 'flight home range' for some 130 miles then, or up to 390.

Well, that 'assumes' I had the right amount of fuel for warm-up, taxi and take off and you are happy with just 20 minutes reserve. It also assumes 263mph is a safe transit speed ( fast enough to keep bounces to a minimum and fast enough to allow a timely response). It also doesn't figure in any fuel used in formation flying. The US used over 300mph at 25,000ft a few years later but then the 1940/41 German fighters aren't quite as fast.

Not sure from where this come from. The 'Bunrin do' book about the Ki-61 states internal fuel as being either 650 or 750 liters (143 or 165 imp gals), this document pretty much agrees with that (199 US gals). With 2 x 200 L (= 105 imp gals) of external fuel the range was phenomenal. The speed listed at the document is 580 km/h, 361 mph, again the book agrees.

It comes from the variable performance depending on armament fit ( another hint that small changes in weight may have big impacts on performance other than speed) and one source claiming range clean was 360 miles but speed was not stated.

Zero have had it's weaknesses, not just the ones you've mentioned. The good protection was not a wide spread thing in most of pre-1941 fighters, though.

even in the summer of 1941 the Americans considered planes without armor and self seal tanks to be training planes. The British were not far off and the Germans had been fitting protection since late 39 early 40. 1940-41 protection migh tnot be up to 1943-44 standards but few countries aside from the Japanese who had the ability to do so were flying unprotected combat planes after 1940.


I'm sure that nobody was expecting for a 109 to be turned into Mustang, once drop tanks are fitted. There were plenty of closer targets, than N. Ireland, where LW bombers would've welcomed escort, though.
Interestingly enough, the 109 was well able to receive a 'consumable' tank (GM-1, 350 kg? or MW-50 tank) behind it's fuel tank without much trouble, CoG wise - one wonders whether there was a potential for LR 109?

Which 109s? the DB601N picked up about 65-75kg over the earlier DB 601 engines and the DB501E and DB 605s were even heavier. Bolt a bit more armor under the oil cooler too?

You can get the the range but can you fight (and succeed) at that range? Again, the 109E may not have been the best platform to try this with. The F with it's lower drag can give more range for the same fuel and is a much better candidate. Sticking several hundred pounds more weight in the 109 may bring it's performance down enough that it has more trouble with Hurricanes.


By the time Merlin XII and XX arrived, the 100 oct fuel and associated +12 lbs boost were well known commodity in the RAF (along with maintenance needed), unlike the time when Merlin III and X were arriving in combat units. I'm not suggesting running those earlier engines at higher boost where the manuals don't say the same.

Just pointing out that special operations in desperate circumstances do not really point the way for day in day out use.
 
The 109Es shot down 20-30 Hurricanes over a 4 month period ( approx one-two days production), or 5-6/month - Hardly dominating or crippling losses if the Hurricanes had been reinforced adequately during those 4 months. Hurricanes also engaged other Axis aircraft, including other Axis SE fighters so not all Hurricane losses were to 109s. Surprisingly the Hurricane had a better kill loss ratio against the 109F than against the 109E which points to the fact that 7/JG 26 was using hit and run tactics, which they could get away with because of the huge overall Axis numerical advantage. If 7/JG 26 was the only axis fighter unit involved it would not have been able to employ the same tactics and would have inevitably suffered much higher losses while inflicting fewer kills.

Reviewing past posts, it seems that 7/JG 26 was credit with about 27 Hurricane kills by Shores and Co. during the 4 month period in early 1941.



Clearly we have to agree to disagree. Its my view that if you have a situation that over a four month period, whenever Hurricanes went into action against Me109E's they lost and they never inflicted any losses, then the Me109s dominate the sky.

To believe that the Hurricane is comparable to the Me109E when the losses in air to air combat are 27 to 0 isn't something that I agree or understand. The Hellcat had a lower kill rate against the Zero but I doubt that you would consider the Zero to be as good as the Hellcat, in fact it would be difficult to find any combat situation over four months when any air combat unit in any airforce had such a success rate.

Malta didn't have 27 Hurricanes to spare and the Luftwaffe didn't have any Me109's to spare as this was the only 109 unit in combat at the time in the area. To say its only a couple of days production of Hurricanes is a distraction as I don't believe the Me109E was in production at the time.

Re the situation with 109F's vs Hurricanes I do not know the details but Shores does say that in the whole of 1941 2 Me 109's were lost. If these were due to fighters or AA fire I simply don't know.
 
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This thread has mentioned the Fw 187 as a possible escort fighter using (2 x) 1200hp engines.

What about the proposed Supermarine Type 324 327?

The 324's max speed was estimated at ~450mph, the 327's at ~465mph. These were about the size of a Typhoon, but with two 1200-1250hp Merlins. FWIW, the top speed of the Typhoon was also estimate at ~460-470mph.

324 and 327 still had small fuel tanks and not much range.
 
Out of existing single-engine fighters, the Mitsubishi Zero certainly fits the criteria in terms of performance and range and just meets service in 1940, but like Tomo said, its structural strength would be an issue to the Allies. Whilst the Fulmar demonstrated an ability to hold its own against the enemy in the Mediterranean, the story might be somewhat different over a heavily defended German target.

Instead of a modified Fulmar, I suggest a better alternative that fits in with a pre-war timescale for development and does not divert from existing RAF expansion plans, i.e. using either the Spitfire or Hurricane; the single-seat Defiant. In 1936 the prototype K8310 without its turret fitted and despite being physically larger demonstrated superior performance to the Hurricane. Granted, that with fixed forward firing armament and fuselage fuel tanks, its performance would drop, it would be an ideal choice for conversion, as it was considered easy to fly and to carry out aerobatics in by the test pilots at the A AEE even with a turret fitted. Any thoughts?
 
Nuuumann, the British had only one plane that was equal to the 109 in 1940, the Spitfire. There was nothing else. Nobody had anything else.
Therefore it was entirely an issue about, for MR/LR attacking (either as escort to bombers, fighter sweeps over France , reinforcement or protecting Med convoys, or...) getting some more range out of the Mk Is, IIs and bit later Vs.

Strategically the British needed a combat radius of 350 miles for that 41/42 period, though even 250 would have been very useful.
Not for every mission of course and for those longer ones, layered approaches would have been necessary.
Layered means that you use shorter ranged fighters first (they could be Spits with less fuel for example, therefore more capable within that range area), then medium ones, then the LR ones for the final legs.
Yes, for say fighter sweeps, you could have fighters protecting fighters for parts of the mission, or more exactly sweeping ahead.
Then the LR ones, having burned off their excess fuel are now competitive again for their leg.

Yes, for those sort of mission it does require a lot of fighters, so that is an issue. For the initial late 43 USAAF missons, Spits did the short stuff, )-47s the medium stuff then the, at that time limited in numbers, P-51s did the final legs, with P-38s filling in as well in the MR/LR parts.

For the British in that 41/42 period they needed to be able to hit Luftwaffe targets in France. Protect Malta, but also protect Malta convoys well out. In North Africa they needed to meet the 109s attacking RAF bombers as they attacked well behind the lines at logistic targets. In NA the RAF were lucky, because Marsaille and his crew (and the others in the theatre copied him) ignored the bombers and ran up scores against the Hurricanes and P-40s. But that was lucky, because the Luftwaffe in 41 and 42 could have slaughtered the RAF bombers on those missions if they wanted ... instead of having a bit of a lark (though not such a lark for the Hurri and P-40 pilots of course).

Therefore, in multiple strategic areas, they needed more Spit range.

This was known by Dowding at the beginning of 1940, hence the experiments, including ordering (memory) 602 squadron to trail the 29 gal wing tanks. Cotton squeezed fuel in everywhere, 20 gals under the seat, behind the seat, in the leading edges, etc. With careful attention to detail (polish, fitting, etc) they actually got more speed out of them than production fighters, despite the extra weight.

Those pictures I posted showed early attempts at what is now called 'conformal tanks'. As per now (and no one calls a F-15 with those .. slow) done carefully you can have minimal speed impacts, though, when full they will impact climb. But in those sort of missions, you have the safe space to do a slower and more fuel efficient climb.
 
Air defence of the Royal Navy and Malta convoys was carried out by FAA aircraft (the entire point of the FAA's existence as my father, an ex FAA pilot, fulminated as British warships were struck by Argentinian aircraft in 1982...and he didn't mean just close range defence of the ships) and land based RAF Blenheims and Beaufighters. Reconnaissance was often performed by Marylands and Gibraltar based Sunderlands. They had an important role to play in keeping the ULTRA decrypts secret, appearing as if by chance over Italian units that the British already knew full well had put to sea. This motley band, including the much despised Fulmars, did alright against the Italians and later shot down some German bombers.
The Malta based fighters were for the defence of Malta, though they did sortie to cover the convoys as they neared the island.
The Bf 109 had limited range too, even with a drop tank.

Sholto Douglas nicely summed up the British defensive mind set and definition of air superiority in 1938.

"Our objective is not to prevent enemy bombers reaching their objectives, though it would be nice if we could, but to cause a high casualty rate among enemy bombers, with the result that the attack will dwindle rapidly to bearable proportions."

No mention of fighters, and in December 1940, after the BoB he reiterated this position.

"The best, if only way of achieving air superiority is to shoot down a large proportion of enemy bombers every time they come over.........I would rather shoot down fifty of the enemy bombers after they had reached their objective than shoot down only ten before they do so."

The Royal Navy lowered the bar. They were content to break up enemy formations thus preventing accurate bombing of their ships. This the FAA did rather well prior to the arrival of the better equipped and better trained Luftwaffe in the Mediterranean.

Cheers
Steve
 
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With careful attention to detail (polish, fitting, etc) they actually got more speed out of them than production fighters, despite the extra weight.

But these aircraft were no longer fighters once armour and armament had been removed.

What an F-15 has got to do with this I have no idea :)

Cheers

Steve
 
Without that, those 'tired old puffers' (as the Luftwaffe called them) would have suffered appalling losses.

I knew I recognised that phrase. It was not the Luftwaffe that called the Hurricanes that but a fighter pilot of 5./JG 51, a Leutnant Ernst Oskar Lessing, given name Hans-Otto.

You forgot to mention that on the day after he wrote the phrase in a letter to his parents he was shot down and killed, on 18th August 1940, by an "old puffer".

Incidentally I believe that he had four, not five, victories when he was killed, a Potez 63, a Spitfire and two "old puffers".

You might also have mentioned that his much admired Staffel commander, mentioned in the letter, was also killed that day. Hauptmann Horst "Jakob" Tietzen, an immensely experienced pilot and veteran of the Spanish Civil War, the fourth Luftwaffe pilot to amass 20 victories, was also shot down by an "old puffer". He may have been a victim of Squadron Leader Peter Townsend of RAF No. 85 Squadron.

It may just be that Lessing's arrogant analogy proved less than accurate.

Cheers

Steve
 
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Then the LR ones, having burned off their excess fuel are now competitive again for their leg.

Even 350 a mile radius requires more fuel in the tanks when the drop tanks are let go than the local interceptor has at take off.




This was known by Dowding at the beginning of 1940, hence the experiments, including ordering (memory) 602 squadron to trail the 29 gal wing tanks. Cotton squeezed fuel in everywhere, 20 gals under the seat, behind the seat, in the leading edges, etc. With careful attention to detail (polish, fitting, etc) they actually got more speed out of them than production fighters, despite the extra weight.

While the cameras weighed something Cotton also left out part or all of the guns. Going back to four .303s may not be what you want to do.

Those pictures I posted showed early attempts at what is now called 'conformal tanks'. As per now (and no one calls a F-15 with those .. slow) done carefully you can have minimal speed impacts, though, when full they will impact climb. But in those sort of missions, you have the safe space to do a slower and more fuel efficient climb.

You can call them what you like, hanging big wacking tanks under each wing is going to slow the airplane down.

800px-McDonnell_Douglas_F-15C_with_the_conformal_FAST_PACK_fuel_tanks_060905-F-1234S-017.jpg


These are F-15 tanks and depend, in part, on the airflow being disrupted by the large air intakes. They actually help smooth the airflow down the side of the plane.

Not the same thing as hanging a 70imp gallon tank under a wing no matter how pointy you make it or how well it follows the bottom contour of the wing.

I can't fins an on line picture of the real 40 gal tank used on the Spitfire II but here is a picture of model.

Hasegawa-Spitfire-MkII-LR-20.jpg


It may not be very pointy but it conforms pretty well to the wing. The rear end tapers.

You keep missing the point about climb. The Allison P-51s were fast, very fast. But were NOT air superiority fighters because they could NOT climb. It isn't about having a safe area to climb to altitude, it is about STAYING at altitude once the fight starts and/or being able to regain altitude during breaks in the fighting. Plus fast climbing fighters can break by climbing. Usually a climbing turn and since turning, even gently, reduces the climb rate a poor climber doesn't have that option and can't even follow a plane that does.
 
We seem to be suffering from tank confusion.

The two 70 gallon tanks pictured in post #12 were only ever mock ups and never went into production. It was the 29 gallon tank, usually referred to as a 30 gallon tank which was expected to cause a reduction in speed of 3 mph (very optimistic in my opinion).
Only one tank was fitted to the port wing. A prototype was tested on P9565 and looked like this.

IMG_0702_zpseb1f44eb.gif


The handling characteristics of the aircraft thus equipped were reported as "poor" and diving at over 350 mph the ailerons became very heavy, "considerable force" being needed to hold up the port wing. Unsurprisingly the system never saw service.

The next effort was to fit a single 40 gallon tank under the port wing of Spitfire II A P8036.

IMG_0703_zpsa8b0b786.gif


This time things went better, largely due to the metal ailerons now fitted. The report reads,

"On take off the control column must be held well over to the right side to keep the aeroplane level, but as the aeroplane accelerates it can be moved nearer the central position.
Whilst extra weight on the port wing can be felt, it does not seriously affect the flying qualities of the aeroplane and this particular aeroplane is considered pleasant to fly. The metal ailerons have brought about a marked improvement in lateral control since the report on the Mark Iwith under wing fuel tank was issued. This aeroplane is considered satisfactory as a fighter."

Satisfactory, maybe, but forget 3mph.
At 15,000ft this aircraft had a top speed of 321 mph. That is a full 24 mph slower than a "normal" Spitfire IIA at 345 mph and a serious reduction in performance.
Time to climb to 15,000 ft was increased from 5 minutes (@2,770 ft/min) to 6 minutes and 48 seconds (@1,990 ft/min).
Maximum speed at 20,000 ft fell from 351 mph to a mere 320 mph.
Time to climb to 25,000 ft went from 9 minutes and 36 seconds to 14 minutes and 6 seconds.
The estimated service ceiling of the tank equipped version was nearly 4,000 ft lower at 33,900 ft.

This is not the sort of degradation in performance that some here are anticipating. Those are the real figures from Boscombe Down's official reports on the two aircraft.

Despite this aircraft thus modified went to Nos. 66, 118 and 152 Squadrons. They were used on extended range escort and patrol missions. Fighter Command was hardly going to instigate a change on the Spitfire across the organisation which so reduced the performance of its premier fighter.

Cheers

Steve
 
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Out of existing single-engine fighters, the Mitsubishi Zero certainly fits the criteria in terms of performance and range and just meets service in 1940, but like Tomo said, its structural strength would be an issue to the Allies. Whilst the Fulmar demonstrated an ability to hold its own against the enemy in the Mediterranean, the story might be somewhat different over a heavily defended German target.

Actually, SR6 mentioned the structural issues 1st :)

Instead of a modified Fulmar, I suggest a better alternative that fits in with a pre-war timescale for development and does not divert from existing RAF expansion plans, i.e. using either the Spitfire or Hurricane; the single-seat Defiant. In 1936 the prototype K8310 without its turret fitted and despite being physically larger demonstrated superior performance to the Hurricane. Granted, that with fixed forward firing armament and fuselage fuel tanks, its performance would drop, it would be an ideal choice for conversion, as it was considered easy to fly and to carry out aerobatics in by the test pilots at the A AEE even with a turret fitted. Any thoughts?

Seem like you are not aware of 'my' Defiants; I've modified some existing drawings to get them :) The pilot's compartment is moved back (like they did for serial F4Us), so the fuel tank is between pilot and engine.
Though, I'm not sure that performance levels would've been on par with Spitfire on same engines.
 

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Whatever long range fighter is hypothetically developed it won't be from one of the interceptor fighters developed by the British in the 1930s.

Spitfire Vs were delivered to Malta from Gibraltar starting in October 1942. This was a flight of over 1,000 miles. To do it a 29 gallon fuel tank was fitted behind the pilot, an enlarged oil tank was fitted beneath the engine and a 170 gallon ferry tank fitted beneath the fuselage. The armament was reduced to a token two .303 machine guns.
On arrival on Malta the ferry equipment was removed and normal armament and tropical filters fitted.
This is hardly a practical long range fighter!

Cheers

Steve
 
Thank you.

to add to it.

Fitting the fuel internally would not have caused quite as much performance drop but the penalty would still be substantial. The loss of 3,000ft or more of operational altitude (which is always 3-5,000ft below the service ceiling) was especially troubling at the time. Combats had started at 30,000ft and above during the BoB. One side or the other diving from that height even if the combats ended thousands of feet lower. It turned out that the the altitudes combat occurred at went up very slowly due to a number of factors ( needed better oxygen equipment for one) but people were anticipating a much quicker move to high altitude combat than occurred. Putting fighters into production that could NOT fight at the same altitudes as existing fighters wasn't going to happen right away. The low flying Spits were an expedient that worked because there WERE high flying Spitfires covering them in many cases.
 
Seem like you are not aware of 'my' Defiants; I've modified some existing drawings to get them :) The pilot's compartment is moved back (like they did for serial F4Us), so the fuel tank is between pilot and engine.
Though, I'm not sure that performance levels would've been on par with Spitfire on same engines.

The main trouble I have with single seat Defiant's is that the 360mph speed was an estimate, that doesn't seem to have anything to back it up. The original Defiant was flown as single seater, with the turret position faired over but not out.
That is to say the canopy was continued back and the hole for the turret covered up but a dummy turret or structure the width of the turret was not fitted even though ballast was. Maybe accounts exist somewhere but no great change in speed seems to have been noted when the turret was fitted. BP didn't do that good a job fitting the Merlin XX either. Speed only increased about 8-13mph due to the larger radiator creating more drag. How the plane was supposed to pick up over 40mph by deleting the turret has never been really explained.
Perhaps B-P was listening to the same guys that were telling Sidney Camm that thick wings wouldn't be a problem on the Hawker Typhoon?
 

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