Why the heck did they design it that way?

[wuzak]

All sorts of "stuff" was done or could have been. In addition to the leading edge tanks mentioned, there was a tank used in PR spits never used on fighters it went under the pilots seat. The Griffon engine moved things about and increased the forward tank capacity. However it seems to me things were not that pressing for more range until 1942 when the RAF started to receive the first Mustangs anyway.

Even with the Mustang, I don't believe the RAF was pushing that hard for extra fighter range.

Work on the Spitfire MK VIII started in early 1942 but the FW 190 force the stop gap MK IX into production. The MK VIII had a low back, bubble canopy rear fuselage tank bigger front tank however in addition to carrying more fuel the later Merlin generally used more fuel.

Most VIIIs had the normal rear fuselage, not the cut down rear fuselage with bubble canopy.

Supermarine Spitfire (late Merlin-powered variants) - Wikipedia

Similarly, most XIVs had the standard rear fuselage, but some had the cut down rear fuselage with bubble canopy.

Even a few Mk XVIs (IX with Packard built Merlin 266) had the bubble canopy.

The VIII, being the definitive 2 stage Merlin Spitfire, had the fuel in the inner wing leading edges, the IX did without.

 

[pbehn]

The whole thing is a dogs dinner Wuzak, I was talking about mainly what they intended, other things got in the way.

 

[wuzak]

The whole thing is a dogs dinner Wuzak, I was talking about mainly what they intended, other things got in the way.

Hence the "interim" types - the V, IX and XIV - were produced in greater numbers than the "definitive" versions - the III. VII/VIII, 21.

 

[pbehn]

Hence the "interim" types - the V, IX and XIV - were produced in greater numbers than the "definitive" versions - the III. VII/VIII, 21.

Much of the production was based on what they had in the factory, great fun for model makers but a bit confusing, a low back Mk VIII looks much more modern and advanced than most Mk XIV s

 

[michael rauls]

All sorts of "stuff" was done or could have been. In addition to the leading edge tanks mentioned, there was a tank used in PR spits never used on fighters it went under the pilots seat. The Griffon engine moved things about and increased the forward tank capacity. However it seems to me things were not that pressing for more range until 1942 when the RAF started to receive the first Mustangs anyway. Another thing to bear in mind was the Typhoon was supposed to replace the Spitfire but never did. Work on the Spitfire MK VIII started in early 1942 but the FW 190 force the stop gap MK IX into production. The MK VIII had a low back, bubble canopy rear fuselage tank bigger front tank however in addition to carrying more fuel the later Merlin generally used more fuel.

All very interesting. It's hard to imagine wanting to replace the spitfire with anything unless this was infact a quest for more range. I have read so many different statements as to the range of the Typhoon and its ultimate reincarnation the Tempest over the years I wouldn't even have an idea if this might be the case. Maybe as a replacement for the Huricane I can at least see the motivation but for the spit that kinda leaves me wondering what they were thinking.

 

[pbehn]

All very interesting. It's hard to imagine wanting to replace the spitfire with anything unless this was in fact a quest for more range. I have read so many different statements as to the range of the Typhoon and its ultimate reincarnation the Tempest over the years I wouldn't even have an idea if this might be the case. Maybe as a replacement for the Huricane I can at least see the motivation but for the spit that kinda leaves me wondering what they were thinking.

Both Hurricane and Spitfire were built to the same requirement. Supermarine were a sea plane and race plane company, they produced a high spec "racer". Hawkers being descended from Sopwith were a fighter company, they produced a low tech design that they knew they could produce in numbers. Before the war started Supermarine had produced so few Spitfires that they nearly lost the contract, Hawkers were producing Hurricanes so quickly the RAF couldn't form squadrons and train pilots quickly enough to accept them, they were allowed to sell it to other nations. Whatever the Hurricanes faults were, there was never a shortage of them in the early years.


The Hurricane was basically obsolete in 1940 but fighting on home ground with RADAR control and the boost that 100octane fuel allowed meant it could hold its own. The Spitfire as designed was obsolete in 1941/42. The two stage Merlin with the fuel needed to run it took the Merlin up to circa 2,000HP eventually. This was the power output projected for the next generation of fighters the which Hawkers started working on as soon as the Hurricane, flew the Typhoon and Tornado. The Tornado bit the dust when the Vulture was abandoned in favour of Merlin development, the Typhoon disappointed as an dodgy airframe with a problematic engine. Eventually the Tempest development of the Typhoon with a Sabre or Centaurus engine became one of the top performers of any piston aircraft, but only at low level, the Spitfire with a Griffon ran it close at low level but was much better at high altitude. Work on the Fury/Sea Fury started in 1942 and it flew in 1945, only the Sea Fury was produced but this certainly had longer range.

 

[GrauGeist]

The Hurricane was to the British as the P-40 was to the U.S. - they were both available in solid numbers when the war started, they were able to hold their own in spite of shortcomings and they both saw service on virtually every front of the war.

 

[michael rauls]

Both Hurricane and Spitfire were built to the same requirement. Supermarine were a sea plane and race plane company, they produced a high spec "racer". Hawkers being descended from Sopwith were a fighter company, they produced a low tech design that they knew they could produce in numbers. Before the war started Supermarine had produced so few Spitfires that they nearly lost the contract, Hawkers were producing Hurricanes so quickly the RAF couldn't form squadrons and train pilots quickly enough to accept them, they were allowed to sell it to other nations. Whatever the Hurricanes faults were, there was never a shortage of them in the early years.


The Hurricane was basically obsolete in 1940 but fighting on home ground with RADAR control and the boost that 100octane fuel allowed meant it could hold its own. The Spitfire as designed was obsolete in 1941/42. The two stage Merlin with the fuel needed to run it took the Merlin up to circa 2,000HP eventually. This was the power output projected for the next generation of fighters the which Hawkers started working on as soon as the Hurricane, flew the Typhoon and Tornado. The Tornado bit the dust when the Vulture was abandoned in favour of Merlin development, the Typhoon disappointed as an dodgy airframe with a problematic engine. Eventually the Tempest development of the Typhoon with a Sabre or Centaurus engine became one of the top performers of any piston aircraft, but only at low level, the Spitfire with a Griffon ran it close at low level but was much better at high altitude. Work on the Fury/Sea Fury started in 1942 and it flew in 1945, only the Sea Fury was produced but this certainly had longer range.

Seems like the spitfire had qualities that made more than competitive ( at least where the mission profile dictated that range wouldn't be a huge factor) like verry high critical mach, good general maneuverability, and at least competitive speed/ climb as engine horse power upgrades were made. Maybe roll rate was less than one would hope for? I would be fascinated to here the reasons you believe it to have bean obsolete so early on.

 

[michael rauls]

The Hurricane was to the British as the P-40 was to the U.S. - they were both available in solid numbers when the war started, they were able to hold their own in spite of shortcomings and they both saw service on virtually every front of the war.

Good way to put it. I didn't mean to disparage the Huricane in my earlier post( a very under appreciated type in my opinion as was the p40) just that I could see the reasons to be looking for a replacement by 40/41.

 

[pbehn]

Seems like the spitfire had qualities that made more than competitive ( at least where the mission profile dictated that range wouldn't be a huge factor) like verry high critical mach, good general maneuverability, and at least competitive speed/ climb as engine horse power upgrades were made. Maybe roll rate was less than one would hope for? I would be fascinated to here the reasons you believe it to have bean obsolete so early on.

Just the engine power output made it obsolete. At the time of its design, engine power was based mainly on swept volume and the Merlin was one of the smallest. The Mk V Spitfire was completely outclassed by the Fw190, without the extra power of a two stage supercharger and higher octane fuel it would never have closed the gap. With the wing tips removed the Spitfires roll rate wasn't too bad, its problem was the Fw 190 was exceptional. Within that there are huge generalisations, from the start to the end of the war the Spitfire doubled in weight, the wings mean they all look like Spitfires but they were very different planes just sharing similarities.

 

[pbehn]

Good way to put it. I didn't mean to disparage the Hurricane in my earlier post( a very under appreciated type in my opinion as was the p40) just that I could see the reasons to be looking for a replacement by 40/41.

It was only seen as a stop gap or interim solution even by Hawkers, as per my previous post Hawkers were working on its replacement(s) when the spec was issued in March 1938, the Hurricane just started being introduced in Dec 1937. The Tornado prototype first flew on 6 Oct 1939.

 

[stona]

The Spitfire was the result of the quest for speed and firepower. Endurance (which people keep referring to as range) was consciously sacrificed in pursuit of the other two.
The result was actually a conflation of the specifications for two types of British fighters, 'zone' and 'interceptor' fighters. The Spitfire (and Hurricane) shared attributes of both whilst being neither. In reality both were a new type of interceptor, one that actually worked in Britain's developing coordinated system of air defence.
Cheers
Steve

 

[Shortround6]

I am not sure if endurance/range was actually sacrificed as much as it was pretty much left alone.
The Gloster Gladiator held 72 gallons of fuel, the Hawker Fury about 50 gals and the Hawker Demon about 73 gallons.
Granted their smaller engines used less fuel but a monoplane was going have a higher cruise speed even if throttled back.
Endurance at the speeds used might be within 1/4 hour to 1/2 hour of each other (including Spits and Hurricanes?)
If you don't ask for higher endurance than existing fighters you aren't going to get it, especially if asking for large increases in speed and gun weight.

I would note in passing that as of Jan 1940 there were 18 fighter squadrons equipped (at least partially) with Blenheim MK IFs.
This means were more squadrons with Blenheims than with Spitfires.
Britain had a long range/high endurance fighter. It just wasn't very good (and it wasn't intended to be much more than a place holder for the Beaufighter).

They were also basically asking for monoplanes of over 300 MPH to operate out of the same sized airfields that the Biplanes operated out of.
Gladiator could take 320 to 450 yds to clear a 50 ft screen depending on engine/boost and prop and it took 420 yds to land from 50ft using the wheel brakes.
The Gladiators with 3 blade props used a metal fixed pitch prop.

 

[fastmongrel]

Increasing fuel by 10 to 15% doesnt mean you get 10 to 15% extra range.

 

[ClayO]

Another issue is manufacturing. The Spitfire and Hurricane were good enough during the BoB, the main problem was getting enough of them.

In a production line, any change requires retooling, changes to documentation, procedures, testing, and so on. Early in the war there was no time for any of that. Another complication was the intermittent need to repair bomb damage to the Supermarine and Hawker factories: the quickest way to repair something is to put it back the way it was, not try to make improvements during the repair job.

 

[Ivan1GFP]

Seems like the spitfire had qualities that made more than competitive ( at least where the mission profile dictated that range wouldn't be a huge factor) like verry high critical mach, good general maneuverability, and at least competitive speed/ climb as engine horse power upgrades were made. Maybe roll rate was less than one would hope for? I would be fascinated to here the reasons you believe it to have bean obsolete so early on.

Regarding the Spitfire, there are a couple factors that I have not seen mentioned yet.
First of all, the Mk.V and Mk.IX were only "interim" versions but the "definitive" Mk.VIII was a heavier aircraft that did not perform quite as well. With the lighter Merlin engine, you really didn't need the extra structure as you might with the Griffon in the Mk.XIV.
I believe the revised wing structure with the versions such as Mk.21 did not really make it into the war so in this context may not be relevant.
Although the Spitfire had an excellent turn radius AND an excellent roll rate in later versions, its speed was always rather low for the installed power.
If you compare the Spitfire and Mustang with similar model engines, the Mustang is consistently about 30 MPH faster.
It took a Griffon engine Mk.XIV to match the speed of a Merlin Mustang.
Laminar flow wings, low drag and high speed at the possible cost of turn performance was preferred by the end of the war and the successor (Spiteful / Seafang) was a much higher speed aeroplane.

- Ivan.

 

[pbehn]

Regarding the Spitfire, there are a couple factors that I have not seen mentioned yet.
First of all, the Mk.V and Mk.IX were only "interim" versions but the "definitive" Mk.VIII was a heavier aircraft that did not perform quite as well. With the lighter Merlin engine, you really didn't need the extra structure as you might with the Griffon in the Mk.XIV.
I believe the revised wing structure with the versions such as Mk.21 did not really make it into the war so in this context may not be relevant.
Although the Spitfire had an excellent turn radius AND an excellent roll rate in later versions, its speed was always rather low for the installed power.
If you compare the Spitfire and Mustang with similar model engines, the Mustang is consistently about 30 MPH faster.
It took a Griffon engine Mk.XIV to match the speed of a Merlin Mustang.
Laminar flow wings, low drag and high speed at the possible cost of turn performance was preferred by the end of the war and the successor (Spiteful / Seafang) was a much higher speed aeroplane.

- Ivan.

It has been discussed at length that the MkV and IX were interim versions on his and other threads. If you compare the P-51 with the Spitfire you find that the Spitfire was in service in 1939 while the P-51 with Allison engine first appeared at Dieppe in 1942. By this time the Spitfire had already made the wars highest interception at 43,000 ft, it was some time later that the P-51 appeared with the Rolls Royce engine that helped it make its name (late 1943). North American only ever contracted to produce a better fighter than the P-40. It was the British who ordered the Mustang, they received 500 Allison engined aircraft which were good bit not substantially better than aircraft in service like the Typhoon and Mk IX Spitfire.

 

[Ivan1GFP]

It has been discussed at length that the MkV and IX were interim versions on his and other threads. If you compare the P-51 with the Spitfire you find that the Spitfire was in service in 1939 while the P-51 with Allison engine first appeared at Dieppe in 1942. By this time the Spitfire had already made the wars highest interception at 43,000 ft, it was some time later that the P-51 appeared with the Rolls Royce engine that helped it make its name (late 1943). North American only ever contracted to produce a better fighter than the P-40. It was the British who ordered the Mustang, they received 500 Allison engined aircraft which were good bit not substantially better than aircraft in service like the Typhoon and Mk IX Spitfire.

Hello Pbehn,
No disagreement from me on most of your points but please recognize that I wasn't saying that the Mustang was a "better" fighter.
What I was saying was that speed was somewhat lacking in the Spitfire as compared to contemporaries especially at low altitude.
It had advantages such as a very high climb rate but it also had some limitations because of its thin wing. The larger wheels that were needed for the heavier later models did not really fit entirely inside the thin wing. The ammunition capacity was low.

As for the Mustang, what people sometimes don't know is that even with the Allison engine, it was relatively fast at low altitude. The Mustang Mk.II (P-51A) was the fastest version below 10,000 feet until the P-51H came along. The P-51A was making the same true air speed at 15,000 feet as the Spitfire Mk.IX did at 25,000 feet. Think about what that means for an aeroplane with a single stage Allison to compare in that manner to a two stage Merlin and the difference in installed power. For what it's worth, although the Typhoon might catch an Allison Mustang at low altitude, the Spitfire Mk.IX doesn't even come close.

- Ivan.

 

[pbehn]

Hello Pbehn,
No disagreement from me on most of your points but please recognize that I wasn't saying that the Mustang was a "better" fighter.
What I was saying was that speed was somewhat lacking in the Spitfire as compared to contemporaries especially at low altitude.
It had advantages such as a very high climb rate but it also had some limitations because of its thin wing. The larger wheels that were needed for the heavier later models did not really fit entirely inside the thin wing. The ammunition capacity was low.

As for the Mustang, what people sometimes don't know is that even with the Allison engine, it was relatively fast at low altitude. The Mustang Mk.II (P-51A) was the fastest version below 10,000 feet until the P-51H came along. The P-51A was making the same true air speed at 15,000 feet as the Spitfire Mk.IX did at 25,000 feet. Think about what that means for an aeroplane with a single stage Allison to compare in that manner to a two stage Merlin and the difference in installed power. For what it's worth, although the Typhoon might catch an Allison Mustang at low altitude, the Spitfire Mk.IX doesn't even come close.

- Ivan.

How is the Spitfire a contemporary? Only 500 Mustang Mk I arrived in UK with Allison engines. When did the Mustang Mk II (P-51A) appear in service? The contract was placed in June 1942 and 360 were built before production switched to P-51B/C, since it only performed at low level did it out perform Griffon Spitfire Mk XII which was in production from Oct 1942. How many P-51As (Mustang II) were deployed to Europe, they must have been needed if they were so much better than everything else.

 

[Shortround6]

rather than degenerate into another Spit vs P-51 argument, I do think it more interesting to stay on topic.
WHY were certain (or actually most) aircraft designed they way they were?
Aerodynamic knowledge was advancing at frantic pace. Like for the Americans to go from this

First US Army aircraft with flaps at end of 1934/ beginning of 1935 to this

Laminar flow and double slotted flaps.

by the summer of 1942. 7 1/2 years.
Please note that the British Whitley started life without any flaps. They were added early in the development but too late to change that 8 1/2 degree downward tilt of the fuselage. These early flaps were pretty much airbrakes that added drag, they did little, if anything, for lift.

New materials and heat treatments and new methods of fabricating parts.

Size of airfields, types of fuel. Many things changed but since it took 2-4 years to bring a plane from sketches on paper to squadron service many planes were out dated on the day they first flew with an operational squadron. Only thing was it was going to take several years for the new prototype to reach squadron service.