Long range, high speed Spitfire fighter: the best approach?

[Glider]

This also may be of interest. It shows how the rear tank was standard in the later Spit IX

 

[vinnye]

From Wiki ;
The Mk Vb was the first Spitfire to see extensive overseas service. On 7 March 1942, 15 Mk Vs carrying 90-gallon fuel tanks under their fuselages took off from HMS Eagle off the coast of Algeria on a 600-mile flight to Malta.[158]

In the months that followed, some 275 Mk Vb and Vc Spitfires were delivered to the beleaguered island, with the Americans generously providing help by allowing the USS Wasp to be used to fly two lots of Spitfires to the islands. Wooden wedges were used to allow the Spitfires to leave the carrier with partial "takeoff" flap settings. (Once the aircraft had gained altitude, the pilot would open the flaps fully, the wedges would fall out and the flaps could then be closed.) In "Operation Calendar" on 20 April 1942, 47 Spitfires and pilots of 601 and 603 Squadrons flew from Wasp to Malta.[159] In "Operation Bowery" on 9 May 1942, another 50 Spitfires flew from Wasp and 14 from Eagle. Sixty of them landed on Malta. One Spitfire with a defective long range fuel tank landed back on the Wasp, despite lacking a tailhook.[160] In "Operation Style" on 3 June, a further 32 Spitfires flew to Malta from HMS Eagle, through they were intercepted en route and four were shot down.[161] However, the carriers were thought to be vulnerable to attack from the Luftwaffe while out at sea[162] so in late October through to early November, a total of 12 Spitfire Vcs, equipped with a single huge 170-gallon drop tank, flew direct from Gibraltar, a distance of 1,000 miles.[145] This meant a flight time of more than five hours.

I did not know that they used such large tanks to fly direct.

 

[Edgar Brooks]

It really is quite incredible; we start with an incorrect belief, regarding the Mk.V, and, when I correct that, everyone piles in with material about the Mk.IX, even going as far as including a page from a post-war manual, and 1945 test reports on a specially converted airframe.
I did not think I would need to remind you all that the IX is/was a different airframe from that of the V, with different capabilities, and different CofG settings. Also, the aircraft that did the non-stop flight between Gibraltar and Malta, carried no cannon, had reduced ammunition on the remaining .303" Brownings, and preferably needed still-air conditions to give them a chance. They, most certainly, did not carry any fuel behind the pilots.
As far as Malta is concerned, the siege ended at the end of December 1942.

The accident investigation people of the day concluded that the loss of Spits due to wings coming off dropped away after the bob weights (etc) were introduced.

Can you tell me where (and when) this report is, please, because I've never seen it, or any mention of it.

 

[Glider]

I think you will find that the Mk V was a very similar airframe to the Mk IX. The weights were different of course but in essence they were very similar, some of the early Mk IX's being converted mk V's.
No one is denying that the Mk V didn't have the rear tanks as by that time the Mk V wasn't the formost version but there was no reason why they couldn't have done these changes to a Mk V

 

[Juha]

Hello Edgar
as I wrote in my previous message, both Shores and Price say that those Spit Vs which flew from Gibraltar to Malta had the rear fuselage 29gal tank. Only 2 mgs in place. the first flight was late Oct 42, on 25th, and the Axis had fighters in Tunisia until early May 43.

Juha

 

[Shortround6]

I think you will find that the Mk V was a very similar airframe to the Mk IX. The weights were different of course but in essence they were very similar, some of the early Mk IX's being converted mk V's.
No one is denying that the Mk V didn't have the rear tanks as by that time the Mk V wasn't the formost version but there was no reason why they couldn't have done these changes to a Mk V

While the airframes were very similar that does NOT mean you can add the same accessories/fuel tanks. the Merlin 60 series engines weighed roughly 250-270lbs more than the Merlin 45-55 engines. They also used 4 Blade propellers instead of 3 blade did they not? A lot more weight forward of the CG, Granted teh MK IX had the bigger radiators behind but it is all about moment arms. How many pounds at how many inches from the CG. A lot of Spitfires carried ballast to keep the CG located properly but without ballast a MK V is a lot lighter in the nose than a MK IX so adding weight in the tail is going to be harder to balance. Some (all without tanks?) MK IXs carried 87.5 of ballast in the tail, I don't know if the planes with the fuel tanks carried the same or less ballast but even at a distance 1/3 of the way to the tail location that is only 262.5lbs. That is about 36 Imp gallons of fuel NOT counting the weight of the tank/s.
If MK IXs were considered dangerous to fly with rear tanks what is a MK V going to be with around 300lbs less weight in the nose?

 

[Edgar Brooks]

Shortround has it exactly; to counteract the extra weight/moment arm of the longer, heavier 60-series Merlin + 4-blade prop, the oxygen bottle (sometimes two) was moved to the rear hatch, and lead weights were installed near the tail wheel (on the XIV, with the even heavier Griffon, they went into the fin.) This meant that the IX, with weights removed, had a fighting chance to have the tank installed, while the V couldn't, without the bigger ferry tank, since it had no means to compensate.
When the XVI was envisaged, with fuel tank, again for reasons of balance the oxygen and compressed-air bottles had to be removed, and fitted into the wings, in the compartments usually filled by the four .303" Brownings. This meant that the XVI had to have the E wing, and the Air Ministry wouldn't countenance that until the gyro gunsight was available. With all of the extra weight, the XVI had to have stronger wheels, and metal-covered elevators just to get off the ground.
The Air Ministry wanted all Spitfires to have rear fuel tanks, but the C.O. of 11 Group (successfully) fought against it, because the tanks adversely affected manoeuvrability, rate of climb, and operational ceiling.

 

[OldSkeptic]

Shortround, oh the Mk V would be more CoG sensitive, even with the elevator fixes, hence my proposing a smaller rear tank (and perhaps an under the seat tank as per some PR versions).

Probably would be the same with 30 gals as a Mk IX with 66 or 75 gals. And you would have to run it down to, perhaps, only 10 gals to return to normal.
Remember 10 gals is only about 100lbs.

You could even do the L shaped stank (ah lah the 109), so when you run it down most is under the pilot.

Might need a bob weight but seems doable.

They shoved more into the PR versions than that, plus they had the camera weight to the rear as well.

 

[Glider]

The very first Spits were tail heavy and had weights in the nose, how much I do not know. There is no reason why the same could not be done again.
I am not trying to pretend that the same tanks as the IX but to pretend that nothing could be done I do not agree with.

Re the decision of 11group not to use the rear tank I can understand as they were interceptors but what about everyone else. The Italian campaign were almost desperate for extra range as well as the 2TAF.

Do you know when 11group won their argument?

 

[Edgar Brooks]

The very first Spits were tail heavy and had weights in the nose, how much I do not know. There is no reason why the same could not be done again.

Early Mk.Is had weights to compensate for the lightness of the two-blade propellers; they were discontinued as soon as the three-blades appeared. Weights caused stress on the engine bearers, so were discarded as soon as possible. The bearers still had to be strengthened, on the V, with the introduction of the more powerful 50-series Merlins.

I am not trying to pretend that the same tanks as the IX but to pretend that nothing could be done I do not agree with.

Excuse me, but where does this "pretend" come from? If the Air Ministry wanted something to be tried, they asked the manufacturers to produce an example (or, if necessary several,) which then went to Farnborough, Boscombe Down, the F.I.U., or any other test centre, to be tested by experienced pilots, who reported back on their findings. If the Air Ministry wanted it to go ahead, they told the factory's Resident Technical Officer, whose job it was to see that it was implemented. Going in the other direction, if the company wanted to institute a change, it had to be presented to the Local Technical Committee, who vetted it, then gave the go-ahead (or not.) there were 1,900 modifications on the Spitfire, and 1090 on the Seafire, not all of which eventually went ahead.

Re the decision of 11group not to use the rear tank I can understand as they were interceptors but what about everyone else. The Italian campaign were almost desperate for extra range as well as the 2TAF.

Italy got the VIII, which had extra wing tanks; do you know, for sure, that the Med H.Q. were wanting fuselage tanks? I've never seen any requests for them, in any files that I've read.

Do you know when 11group won their argument?

As far as I know they never lost it, rather than winning, since they never had the tanks fitted in anything but the XVI, and (possibly) the F.R.XIV with cut-down fuselages.

 

[OldSkeptic]

Everyone seems to be forgetting the "Portal' effect. He was the CAS. His position, which he very actively held until Oct 43 was that a long range fighter was impossible.
He is on record writing to the Americans and Churchill saying that, over and over again.
Two months before the P51B came onto operations he was still arguing with Arnold about it. There was not a single chance he was going to convert Spits to LR operations, he had hung his prestige on that one.

Now, take any organisation, going against the boss's wishes is not a good way to get promoted.
Imagine if someone had successfully fielded a LR Spit on operations, they would have made him look like a fool.
Imagine how he was going to react if, after telling the Prime Minister, in print (many times) that it was 'impossible', then someone comes along and does it .. are you going to be the one who tells him that?
Welcome to the RAF's Siberian Command...or 'here is a nice Antarctic base you can be in charge of'.

There was no way Leigh Mallory (11 Grp head 40 to 42) or Saunders (42+) were going to take those sort of career hits, being competent but not politically savvy didn't get you far in the RAF.
Note how the most innovative areas of it were in theatres well away from Britain and out of Portal's woeful gaze (and he was not happy about it and made that clear, but the DAF had become so successful even he couldn't kill it). As for Malta, Italy, etc? Oh yes Park was pushing for it, look what happened to him, at the end of the war he was told 'there was no position for him'. Tedder did ok, but he had Monty and Eisenhower behind him, that helped, otherwise I think his career would have taken a very left run along the way.

So you got 'self censoring'. If you were a politician like LM, you knew that Portal had hung his hat on the LR 'impossibility', what are you going to do? Prove him wrong, not likely.

As for Boscom Down et al, while they were twittering away if a Spit had 0.5" CoG too far, the USAAF just got on with it, slapped rear tanks into their Mustangs and flew the blasted things into missions.
Note that a Mustang was just as unstable with its rear tank full as a Spit was.
Note that BD were the ones that had earlier said putting cameras in the rear of a Spit was 'impossible ' too. Until Cotton just did it.

This attitude became institutional, to the point where British Mustangs had their rear tanks removed....
Even after the war, think of a British made LR fighter ... yeh short list isn't it.

Even Quill remarks on that. In his book he tells of doing a LR test with a Mk IX, rear tank, 90 gal drop tank, flew to the North of Scotland and back (at low altitude too), same distance as round trip to Berlin.
He commented that at BD they tended to underestimate the average pilot and that if the plane wasn't just absolutely perfect they just wouldn't clear it.
Look at how they frigged around with the Spit 21 and the Spiteful, reading their test reports is almost embarrassing. If it didn't behave just like an earlier Spit in every regime they were not going to clear it.

You can't help but wonder if they would have ever have cleared the Merlin Mustang if it has been a purely British plane, given its stability issues in the beginning. And they would never have cleared it with the rear tank.

 

[Glider]

Early Mk.Is had weights to compensate for the lightness of the two-blade propellers; they were discontinued as soon as the three-blades appeared. Weights caused stress on the engine bearers, so were discarded as soon as possible. The bearers still had to be strengthened, on the V, with the introduction of the more powerful 50-series Merlins.

So we agree that the engine bearer coud be strengthened to take the extra weight.

Excuse me, but where does this "pretend" come from? If the Air Ministry wanted something to be tried, they asked the manufacturers to produce an example (or, if necessary several,) which then went to Farnborough, Boscombe Down, the F.I.U., or any other test centre, to be tested by experienced pilots, who reported back on their findings. If the Air Ministry wanted it to go ahead, they told the factory's Resident Technical Officer, whose job it was to see that it was implemented. Going in the other direction, if the company wanted to institute a change, it had to be presented to the Local Technical Committee, who vetted it, then gave the go-ahead (or not.) there were 1,900 modifications on the Spitfire, and 1090 on the Seafire, not all of which eventually went ahead.

And we agree that there was a process to test the idea if someone had come up with it

Italy got the VIII, which had extra wing tanks; do you know, for sure, that the Med H.Q. were wanting fuselage tanks? I've never seen any requests for them, in any files that I've read.

True but the papers I put forward show that they were very keen on the extra range which is why they used the 90 tanks on opps.

As far as I know they never lost it, rather than winning, since they never had the tanks fitted in anything but the XVI, and (possibly) the F.R.XIV with cut-down fuselages.

And now we are agreeing that they had the rear tanks on the XVI which is almost exactly the same as the IX.

Add the papers I presented that showed the rear tanks were in production for retro fitting to the Mk IX and future installation in new production IX and we have the case for the Mk IX with rear tanks.

I also have other papers which show the Air Ministry when asking about the long range performance of fighters generally included the Spit IX with the rear tanks.

 

[Edgar Brooks]

Note that BD were the ones that had earlier said putting cameras in the rear of a Spit was 'impossible ' too. Until Cotton just did it.

Except he didn't; he put them in the wings, after removing the guns and ammunition.

 

[Edgar Brooks]

So we agree that the engine bearer coud be strengthened to take the extra weight.

Torque, not weight.

And we agree that there was a process to test the idea if someone had come up with it

And reject it if no advantage could be found.

True but the papers I put forward show that they were very keen on the extra range which is why they used the 90 tanks on opps.

Which could be dropped, when necessary, leaving the airframe still capable of combat manoeuvres.

And now we are agreeing that they had the rear tanks on the XVI which is almost exactly the same as the IX.

Except it was configured for ground attack, while the standard IX was earmarked for fighter operations.

Add the papers I presented that showed the rear tanks were in production for retro fitting to the Mk IX and future installation in new production IX and we have the case for the Mk IX with rear tanks.

Good enough for you, 70 years later, but not good enough for those with the responsibility for sending pilots to their deaths.

I also have other papers which show the Air Ministry when asking about the long range performance of fighters generally included the Spit IX with the rear tanks.

The chair-bound Air Ministry mandarins wanted them; those who did the fighting didn't want them.

 

[OldSkeptic]

Except he didn't; he put them in the wings, after removing the guns and ammunition.

n the Mk I PR Type B (also known as Medium Range (MR)) conversions which followed, the F24 camera lenses were upgraded to an eight inch (203 mm) focal length, giving images up to a third larger in scale. An extra 29 gal (132 l) fuel tank was installed in the rear fuselage. It had been envisaged that much larger cameras would be installed in the fuselage immediately behind the pilot, but at the time RAF engineers believed this would upset the Spitfire's centre of gravity. Cotton was able to demonstrate that by removing lead weights, which had been installed in the extreme rear fuselage to balance the weight of the constant speed propeller units, it was possible to install cameras with longer focal-length lens in the fuselage. The Type B was the first to dispense with the heavy bullet resistant windscreen. Many of these early PR Spitfires were fitted with the Merlin XII engine and Rotol constant-speed propeller with the early, blunt spinner of the Spitfire Mk II.[58]

Supermarine Spitfire (early Merlin-powered variants) - Wikipedia, the free encyclopedia

The Mk I PR Type D (also called the Extra Super Long Range Spitfire) was the first PR variant that was not a conversion of existing fighter airframes. The Type D carried so much fuel that it was nicknamed "the bowser." The D shaped wing leading edges, ahead of the main spar, proved to be an ideal location for an integral tank. Accordingly, in early 1940, work started on converting the leading edges, between rib four through to rib 21, by sealing off the spar, outer ribs and all skin joins allowing 57 gal (259 l) of fuel to be carried in each wing. Because the work was of low priority, and with the urgent need for fighters the first two, hand-built prototypes of the PR Type Ds were not available until October. In addition to the leading edge tanks these prototypes also had a 29 gal (132 l) tank in the rear fuselage. An additional 14 gal (63 l) oil tank was fitted in the port wing. The cameras, two vertically mounted F24s with 8 inch (20.3 cm) or 20 inch (50.8 cm) lens or two vertically mounted F8s with 20-inch (510 mm) lens, were located in the rear fuselage. With the full fuel load the center of gravity was so far back the aircraft was difficult to fly until the rear fuselage tank had been emptied. Despite these difficulties the type quickly proved its worth, photographing such long distance targets as Stettin, Marseilles, Trondheim and Toulon.[60]

Once the first two Type Ds, P9551 and P9552[61] had proven the concept the production aircraft, which were soon redesignated PR Mk IV, were modified to increase the leading edge tank capacity to 66.5 gal (302 l) and by omitting the rear fuselage tank. These aircraft were better balanced and had the more powerful Merlin 45 engine as used by the Mk V, along with heated cabins, which were a great comfort to pilots on such long flights. A total of 229 Type Ds were built.[62]

And here is something interesting:

Mk I PR Type F was an interim "super-long-range" version which entered service in July 1940, pending the Type D. The Type F carried a 30 gal fuel tank under each wing, plus a 29 gal tank in the rear fuselage, as well as having an enlarged oil tank under the nose. It was a useful enough improvement that nearly all existing Type Bs and Type Cs were eventually converted to the Type F standard. Operating from East Anglia it was just able to reach, photograph and return from Berlin. 15 of these were based on the Mk V airframe.[10]

The Mk I PR Type G was the first fighter-reconnaissance version and performed a similar low-level tactical role to the Type E. One oblique F24 camera, with either an eight inch or 14 inch lens, was fitted facing to port, between fuselage frames 13 and 14. Two vertical F24 cameras were also installed in the fuselage. The forward camera, installed below the oblique, could be fitted with a five inch or an eight inch lens while the rear camera could be fitted with an eight inch or a 14 inch lens.[64] A 29 gal (132 l) fuel tank was fitted just behind the pilot. The first PR Gs were converted from Mk I airframes and their Merlin II engines replaced with Merlin 45s.[64] Late PR Gs were converted from Mk V airframes. The Type G was fully armed with 8 × .303" Brownings and retained the armoured windscreen and gunsight.[64]

 

[Tante Ju]

Add the papers I presented that showed the rear tanks were in production for retro fitting to the Mk IX and future installation in new production IX and we have the case for the Mk IX with rear tanks.

Are there any papers showing how many production Mark Niners were retrofitted with those rear tanks?

 

[stona]

It's something of an understatement to say that the PR ID was difficult to fly. According to one who flew it:

"You could not fly straight and level for the first half our or hour after take off. Until you had emptied the rear tank, the aircraft hunted the whole time. The centre of gravity was so far back you couldn't control it."

I'd suggest that whilst just about acceptable for a solo reconnaissance aircraft in war time this would be unacceptable for a fighter in squadron service. Formation flying would certainly be challenging!

Cheers

Steve

 

[Juha]

One must remember that PR ID carried 2 cameras in rear fuselage, especially those with 20" lenses were not so light. Of course the 114gal fuel in the leading edges torsion boxes compesated that at least partially. I cannot say was the ID's GC more aft than that of Vc with a full rear fuselage tank and a dt. IMHO only if the GCs were near each other we can draw conclusions from the behavior of ID.

Juha

 

[OldSkeptic]

It's something of an understatement to say that the PR ID was difficult to fly. According to one who flew it:

"You could not fly straight and level for the first half our or hour after take off. Until you had emptied the rear tank, the aircraft hunted the whole time. The centre of gravity was so far back you couldn't control it."

I'd suggest that whilst just about acceptable for a solo reconnaissance aircraft in war time this would be unacceptable for a fighter in squadron service. Formation flying would certainly be challenging!

Cheers

Steve

Mustangs fully fueled up were just as bad (and they also had the issue of lateral instability too in the earlier B/C versions) , the key thing is that they used up that fuel, returning the plane to normal before they got into a potential combat zone.

Usual was, take off an climb on rear tank, initial cruse to rendezvous on rear tank (or at least most of it until the CoG became reasonable), then drop tanks for the rest of cruise and escort phase. Drop them for combat and use normal internal fuel for that and return.

As usual careful planning, training and tactics were the key to success.

They used layered escorts, In 43 and early 44 it was Spits so far, then P-47s then Mustangs so the Luftwaffe couldn't do the obvious trick of doing feint attacks to make the planes lose their drop tanks.
If you had enough of one type then you would use a single type of plane with different fuel loads for the different stages.

As for the Spit, you would use a similar pattern. As for formation flying, who cares by the time they did that sort of stuff tight formations were not used (simply big clumsy targets as they learned through bitter experience).

Good training would be essential of course, though the USAAF threw pilots into Mustangs and sent them off on long range escort missions because the need was so great. I read the account of one pilot, originally on P-47s, then Mustangs arrived, they got a quick go through of the setup and (if they were lucky) a quick test flight, then sent on an escort mission the next day basically.

No reason not to do it with Spits, as said even a Mk V with a 29 gal rear tank and a drop tank could do a 300 mile combat radius missions. That FR version of the MK I showed that, 'fighter recon' planes were expected to fight (though the best low level FR plane by far was the Mustang I, the P-51A).

The reasons the RAF didn't do were simply : Portal, Portal and Portal. He had hung his hat (and reputation) on that it was 'impossible', therefore there was no way it was going to happen, whatever the technical issues were. Heck, I'm quite sure he would have killed the Mustang if he could have.

The funny thing was that the RAF sent off bombers all the time were were hideous to fly when fully fueled up at the beginning of a mission. So it was ok for a bomber crew (including Mosquitos) to start their mission in an unstable, in some cases virtually unflyable and very definitely in a very dangerous state for take off and initial cruise to target.

But not for fighters, the pilots were obviously inferior of course.

You have to see Portal as the heir of the Trenchard dogma ... bombers, bombers and bombers .. and they will always get though .. and win by destroying the enemy's 'moral'.
And everything else was irrelevant. Harris famously wrote that Coastal Command, CC for short, (essential for winning the BoA) was 'an obstacle to victory' and urged that it should be shut down.
Portal half agreed (by his own memos), but was forced (though he fought hard against it) to give resources to CC. One of his famous memos was that CC should not get LR Liberators (totally essential for closing the Atlantic Gap) because ' the Americans might be annoyed that we are not using them for bombing Germany'. Where he was going to get the fuel for his bombers if Britain lost the BoA he never said.

RV Jones (read Most Secret War) tells the story of how he was trying to get the frequency of German night fighter radars, found that no one in BC was interested. Went to a senior BC person to try a get a Mosquito to do it (for obvious reasons as this was an extremely dangerous mission) and spent the time with this senior BC person talking about 'model trains', which was all that person cared about (naturally not his crews being slaughtered).

Never got that Mosquito, but finally got a Wellington crew to do it (????), they succeeded .. and got shot to pieces doing it (amazingly most survived).

And that was the RAF in WW2 ... model trains are so important. Really competent people like Dowding and Park were gotten rid of, Cunningham and Tedder did well .. because they were far away from Portal's woeful gaze and because of their successes the senior British and American people (Monty, Eisenhower, etc) protected them.
Portal was not happy about it as he made clear many times, RAF supporting troops .. heresy. Spits for Malta and North Africa? Took the Prime Minister and the War Cabinet and the CGoS to achieve that against bitter RAF opposition.

To give an example of the RAF's 'Colonel Blimps', at the height of the BoA in mid 42 to mid 43, when the Germans were sinking ships faster than the Allies (even including the US) could be built, in Britain where they were living off stocks which were declining (inc fuel) and the food ration was cut again and again. There was just 5 VLR Liberators based in Iceland.... and Portal complained about 'being forced' to allocate them to 'such a useless task'.

Given the importance of the BoA and how he fought so hard to lose it, killing LR Spits was an easy task by comparison. Imagine him lying to Churchill (because he had to know about the P-51B just about to come on stream) in late 43 that 'the long range fighter is impossible', in writing no less. So bad was he that even (the always politically neutral and usually careful not to offend anyone) official war report on the RAF made special mention of his endless opposition to LR fighters.


And that, gentlemen is the real reason why it didn't happen .. and makes the Merlin Mustang even more of a special story.
Hated by the USAAF at first, tremendous opposition internally, much corporate opposition by other companies.
An orphan. Only A few people and, very importantly Rolls Royce (without their support it would never have happened .. and they never get the credit they due over this) believed in it and made it happen.
And sheer desperation forced the higher USAAF people to grab it.

To be fair, in the end they grabbed it because the 'higher people' worried (for whatever emotional and political reasons) about the hideous losses their bombers were suffering.

 

[fastmongrel]

Aint it lucky the good old USAAF saved us snaggle toothed Brits from our own incompetence we had been getting our ass whuuped for 4 years. That Portal hey bet he got the Iron Cross 1st class from his buddy Adolf.

How about we cut him some slack he might have made the wrong call but then name me a military leader who didnt make wrong calls, with the benefit of our 20/20 hindsight glasses we can criticise but we cant stand in the mans shoes and we couldnt make the call with all the info we have today. Portal might well have had legitamate and justified reasons for not wanting Spitfires wandering over Germany, he might have been under orders from above that conflicted with a desire to build LR fighters.

Just to keep banging on saying Portal killed lots of RAF crew for dogmatic reasons does not work for me.