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Subject: How to fix the design defects of the Spitfire airplane of WW-II.
Shooter    5/26/2005 5:12:16 PM
Given 20-20 hind sight, It is easy to see where R.M. went wrong with the Spitfire! The following list of items is my idea of how they should have done it, IF THEY HAD READ ANY OF THE COMMON TEXTS instead of designing a newer SPAD for the last war! 1. Start with the late Seafire or even better the Martin Baker MB-5! they have contra props and wide track gear. The MB-5 also has a much higher LOS out of the pit forward. This is also one of the Spits larger problems. 2. Change the shape/planform of the wing and eppinage from eliptical to trapiziodal. The eliptical surfaces caused the construction time and cost of the Spitfire to be more than double that of the Mustang and almost as much as the P-38. 3. Reduce the wing cord and thus area by 35-40%! This reduction in surface aria will increase the cruising speed substantialy! This is probably the single biggest defect in the design. The change in aspect ratio will also help fuel ecconomy! 4. To compensate for the increased landing and take off speeds install triple slotted fowler flaps with a long hinge extension. This gives a huge increase in wing area and changes the camber for supirior "DOG FIGHT" ability, should you ever need it! ( because the pilot really screwed up!) At full extension and deflection, they would reduce the landing speed by 11~13MPH? (Slip Stick calcs!) 5. Remove the wing mounted radiators and install a body duct like the P-51 or MB-5! This one change would add ~35MPH to the plane? 6. use the single stage griphon engine and install a "Turbo-charger" like the P-38 and Most American Bombers had. This would increase power and save weight, both significant contributers to performance. 7. Remove the guns from the wings! This would lower the polar moment of rotation and give the plane snappier rates of roll! It also makes room for "wet wings" with much more fuel. A chronic Spit problem. It also fixes the Spit's gunnery problem of designed in dispersion! 8. Install the Gun(s) in the nose! Either fireing threw the prop boss/hub or on either side 180 degrees either side of the prop CL. This fixes the afore mentioned dispersion problem. One bigger gun between the cilinder banks or upto four 20MMs beside the engine or both, depending on what your mission needs were! 9. Make a new gun based on the American 28MM or 1.1" Naval AA ammo! This shell was particuarly destructive, had a very high MV and BC and was all ready in service. A re-engineered copy of the existing gun to reduce weight and increase RoF is a faily simple task. Pay the Americans for it if British spring technology is not up to the task! it also frees up much needed production capasity for other things. 10. Design a new drawn steel "Mine" shell for the above gun! Spend the money to load it with RDX instead of the TNT used for the first 4/5s of the war. 11. Pay North American or Lockheed to design it for you, since the Supermarine staff was to tied up fixing the origional spitfire design to get it done any time soon. Did I miss anything?
 
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larryjcr    RE:Spit XIV vs George Roll Rates   5/7/2006 10:54:23 AM
I'm still preferr to go with the findings of the people who were betting their lives on them! One note here: the US a/c all had larger pits than the Spitfire (the Mustang) was the smallest. I've offered quotes before from RAF pilots who much preferred the Mustang to the Spitfire for exactly that reason for a flight of any serious length -- like three hours or more. Let alone twelve. And tests in a pit mockup do not include people shooting at you. Incentive means quite a lot.
 
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larryjcr    RE:P38 vs P51   5/7/2006 3:52:00 PM
to AE: The last portion of your last post is really the point I've been trying to make all thru this. Any discussion of which a/c is 'best' HAS to be within a very narrow situation context to be valid! The P38 was the escort of choice in the Pacific, and the MTO as well, throughout the war. It was available long before the merlin Mustangs were, and had a different balance of advantages and disadvantages. Much of the question in 8thAF came back to the engine reliability problem that seems to have been local to that warzone, for whatever reason. The Mustang had enough range, and was available in quantity at the same time the US pilot training programs really started turning out pilots to put in them. It was cheaper to build and operate, giving it major logistical advantages. If the 8th AF didn't want the Lightnings, the 9th, 5th and 15th AFs certainly did, so everyone came out ahead. But in assessing the balance of advantages and disadvantages, one of them is this: if a pilot was a few hundred miles from home in an a/c with battle damage, he was a lot better off if that a/c was a P38.
 
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AussieEngineer    RE:Spit XIV vs George Roll Rates   5/8/2006 5:14:50 AM
Combat can be quite a powerful incentive, but still, I'm not going to win an arm wrestle with one of the Wallabies(Oz rugby union team) no matter how much incentive I have to win. There are still limits to human body. One other thing I'd like to point out is that we don't know the speeds of the test in question. Therefore it is quite possible that is actually in agreement with the NACA roll tests.
 
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AussieEngineer    RE:P38 vs P51   5/8/2006 5:31:07 AM
That is definately something I agree on. I don't think anyone but shooter claimed that the one particular aircraft was "the best" of the war. However, I strongly disagree with the claim that the Spitfire wasn't a superb aircraft for what it was designed and that it also excelled in a number of other roles that it wasn't originally intended for. I think the biggest advantage the Mustang had over the Lightning was that it was easy to fly and fight in. The P-51 had automatic boost, mixture and supercharger control. The P-38 was more complex to operate even in the J and L models and especially so in the D-H. That was one of the major reasons for the poor reliability of the Lightning in Europe. The Mustang was also a smaller target. On the one hand the P-38 has 2 engines but on the other it's more likely to get hit. You have to decide whether it is better to get hit and survive or not to get hit at all. That's probably one of the biggest difference in the large scale air combat of Europe vs the lower intensity combat of the Pacific. If you did get hit in Europe, you'd be more likely to get picked off.
 
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larryjcr    RE:P38 vs P51   5/8/2006 10:56:09 AM
As to the Spitfire, yes. I've never argued anything else. It was what the RAF asked for a short range, defensive interceptor, for the UK environment) in about as pure a form as possible, as well as a first rate PR platform. I'd say that as a2g and as a carrier a/c it was marginal, but it was what Britain had and they did their best with it. I doubt that the size matter had much to do with the chances of getting hit. The great majority of a/c hit was the result of the pilot looking the wrong way. Case of Perry Dahl of the 475thFG on one of those 1000 mile missions. Got bounced while stalking a flight of Zeros. Suddenly, tracers going by and a Zero at full deflection, close range and aim on target!! With no time to evade, he 'threw his starboard engine in front of the Zeke and let it take the hits' aimed at his pit, then shoved everything 'to the wall' and ran for the deck. The alison kept cranking in spite of the damage, until the coolant ran out, but those few seconds got him clear of the fight. Flew home one one mill with 82 holes in his a/c, mostly in the starboard cowling! Finished the war with 9 confirmed kills and had a long career in the post war USAF. Again, I'd argue against your use of the word 'intensity'. I'd argue that true intinsity has nothing to do with the numbers involved. If you wanted to refer to 'concentration', I'd have no arguement, but I still see the a2a in the Pacific as being more 'intense' as I'd use the word.
 
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Ispose    RE:P47   5/8/2006 12:07:23 PM
I still think the best overall Fighter of WWII was the P-47. It could perform a variety of roles, was a very good fighter, and excellent ground attack aircraft, and could take a beating and still survive. Remember that all the top scoring P-47 aces in the ETO survived the war...says a lot about the aircraft. Later models with the Paddle bladed props and water booting had excellent performance. Robert Johnson did a mock dogfight with a Spit after getting the new paddlebladed prop and whooped him...outrun, outclimb, and outdive...pretty much controlled the fight. Granted the later Spits pretty much closed the gap but still impressive performance. The late war P-47N's had a tremendous amount of range..as good as any P-51's.
 
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larryjcr    RE:Interesting thing on Spit VIII range   5/8/2006 12:10:58 PM
A couple of things I hadn't gotten to on this. The pressure line carrying exhaust gases may not have to be thick, but it will have to be insulated for much of its length. Exhaust gases are hot, and a lot of things in an a/c (like the rubber coatings in self sealing fuel tanks, not to mention the fuel itself, and the gun ammo) don't like to get too hot. Also, on the idea of expanding the leading edge tanks, you have repeatedly mentioned that the guns are behind the spar, only the barrels are in front. If you're planning on putting the gun barrels thru the tank in some sort of tunnel, I doubt that could be made to work. It would have to be well insulated to protect the tank from the heat of the barrel when firing (see above) and also leave enough room around the gun barrel to permit enough airflow -- the guns were air cooled after all. By the time your tunnel is large enough to permit the airflow, and allow room for the insulation, I don't thing that there would be any tank left.
 
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MustangFlyer    Long Range Spit VIII   5/8/2006 11:18:28 PM
I’ve built a more sophisticated model to calculate various options for a long range Spit VIII (later I'll do one for the P-47 and Mustang). I've used published figures on cruising consumption, combat, etc. Scenario 1 - Standard configuration plus 75 gal (UK) rear tank. 400 mile radius mission, 25 mins combat time allowed for. Mission Range 400 Combat Time mins 25 Spit VIII Capacities (UK Gals) Main Tank 96 Wings 26 Rear Tank 75 Drop Tank(s) 90 Total Fuel 287 Combat Range Calculation T/O & Climb Fuel Use Main Fuel - Rear 26 Drop - Total 26 Cruise to Target Capacity Used Main Fuel - Rear 49 Drop 10 Total 59 Cruise Range (Miles) Main Fuel - Rear 331 Drop 69 Total 400 Combat (25 mins) Fuel Use Main Fuel 52 Total 52 Maximum Return Fuel Main Fuel 70 Total 70 Left 18 Reserve 9.0% Maximum Return Range Main Fuel 535 Total 535 Reserve Range 135 Longer Ranges 500 mile radius is possible if combat time is reduced to 15 or 20 mins (giving 25 and 15 gals reserve). If the wing tanks are doubled to 52 gals, then a 500 mile radius has a 31 gal reserve with 25 mins of combat and 550 miles (Berlin) has 24 gals reserve.
 
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MustangFlyer    RE:Long Range Spit VIII   5/8/2006 11:20:12 PM
Of course if Larry is wrong and some (say 25 gals) of fuel can be retained in the rear tank and the Spit still be fit for combat, this improves even more.
 
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AussieEngineer    RE:Interesting thing on Spit VIII range   5/9/2006 5:32:04 AM
Insulation is a problem that can be solved. Compared to the problems of all the exhaust ducting associated with a turbo-supercharger it is really very minor. Still, the exhaust pressurisation is a nice to have not a must have. That was what I originally envisioned. I believe it was either a Russian or Japanese plane that had a fuel tank straddling the barrel of engine cannon. I'll have to check up on that, I might just be imagining things. If you wanted to be really clever you could even use the petrol to cool the guns. If you assume that the heat produced from firing is equal to the KE of the shell once it leaves the barrel (I'm pretty sure this is a very conservative assumption, I don't see how it could possibly be more). With 30 gal wing tanks the temperature of the petrol would only rise 33*C if all 120 20mm shells were fired at once. It would work just like a vickers machine gun. But anyway if that idea doesn't really appeal to you, it would be simply enough to have a second cell in between the 20mm cannon and the first browning. Connect it to the first by a pipe running under the barrel. There are probably other/better ways to solve that particular issue. No doubt an aeronautical engineering of the 40's should have been able to figure out a suitable solution.
 
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