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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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flamingknives    RE:Aargh! not shooters double entry bookkeeping again   9/20/2005 6:20:34 PM
 
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Shooter    RE:Aargh! not shooters double entry bookkeeping again   9/20/2005 10:30:09 PM
So many things to write about. OBNW>sorry missunderstanding i was refering to the IX not the XIV yes the XIV was 44 but it was a faster climber than the IX which in turn was superior to the P38< Shooter> not according to some books, quoted by larryJCR, that state the Mk9 was faster to altitude than the Mk14. In either case Climb was not important in combat. The Mk9 was not the equal of the P-38 in any important aria of performance! It was slower, shorter ranged and had less fire power. The three most important items of performance! Every thing else is insignificant when it comes to generating kills! OBNW>wrong, how do you get a minus boost figure? isnt that a vacuum?<< Shooter> When the engine is not turning enough RPMs the supercharger acts like a giant pinwheelrestrictor in the inlet and reduces pressure to below atmospheric values. IE, 12.7 pounds absolute instead of 14.7 PSI! That the page you link to has shown this MINUS 2 PSI number the entire time and that you have failed to note it is incredulus to me. That you also were ignorant of the mechanics of engine opperation is also amaising to me. tHAT YOU CONTINUE TO QUOTE FANCIFUL FIGURES about AC performance such as Spitfire cruising speeds that are absolutely impossable to use for the distances required is also beyond my ken. I sugest that you learn how to fly so that we will not be bothered by this kind of nonsence again. OBNW> as shown before the spit crusies faster than than the p38<< Shooter> That you continue to post this clap trap is pathetic. The Spitfire can not use the throttle settings you state and get to even 65% of it's plackard range! That you continue to ignore the fact that hundreds of Spits were lost to fuel starvation due to their pilots use of their reserves when the pilots selected much too high throttle settings and because of it used the fuel that was required to make the trip home! OBNW>by the way the external tank fitted to the spit was not a drop tank as such as there was no capability to rlelease it in flight<< Shooter> ????? OBNW>mminus psi again !!! still not sure how you can get a blower to produce less than asmospheric!<< See above! But just in case you missed it; If the engine is turning slowly, the blower, which relies on imparting kinetic energy to the fuel/air mixture, acts like a giant restrictor in the intake path. OBNW>another thing is that p38 would take upto 60 seconds to get from crusie to acceleration and the twin engines and the complex turbo units required a multitude of setting changes to get them to work in the different mode (later p38 had a lot of these automated which did vastly improve the situation)<< Shooter>This is true for the most part. It only took "up to 60 seconds" if you were new and inexpirianced! Expirianced pilots could do this in as little as five seconds. With the average being less than ten! Shooter from previous post>It is the Spit that has to make up for it's slower speed and then also has to cope with the better acceleration of the P-38 to boot! OBNW>the spit was fitted with racks for two wing bombs and a centrline bomb. = 1000lbs most rocket missions by the spit was with the 8x 60lbs rockets<< Shooter> Please list your refferances for this, as my books all state that the various versions of the various marks were fited to cary ever increasing bomb loads, with only the very late war types able to lift this load. In addition, none of the actual WAR service Marks could cary eight rockets. But my books could be wrong, they often are. I site Mike Spick's "Fighters", page 451 in which he states that only the latest Marks could cary rockets. But like I said, he could be wrong. OBNW>the twin torp p38 is a red herring it never flew operations.<< Shooter>True, but it could cary two Mk-13s! OBNW>the british rocket was not a 3" as you quote as this was the us pre 43 rocket the british was a completely diffent design. although it was smaller than your later 5" model(60lbs vs 80lbs)<< Shooter> The rocket I speak of had an origionaly US three inch OD moter and a much larger British head. It looked like a sausage on a stick and the most seen picture is the Beaufighter firing a slavo at some hapless German ship. OBNW>and the 1600 bombs were from the 43 H model onwards and it wasnt untill the j of 44 did the tripple rockets launchers were replaced with the tree 5x 5" units (prior to 44 you were using the 3" rockets the 5" didnt enter service till 44) << Shooter> Every single service P-38 could cary two 1000 pound bombs and eight to fourteen 5" HVAR rockets. Each Massing ~125 pounds. "Janes all the worlds air craft" and Brassy's "Air craft weapons sytems" OBNW>where you get the 125 pound rockets from i dont know!<< Shooter> Janes, Brassy's and every other referance book I have. see page 809 in the '87-'88 Janes Weapon Systems. OBNW>no you actually said rubbish, over rated implies opion why you have used unsustaiated arguements.<< Shooter> I never sai
 
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Factor X    RE:wing loading/larryjcr   9/21/2005 12:33:27 AM
SH!!T ! ! ! I just gave up after learning you guys don't know how to use paragraphs. If you could post your thoughts in organized paragraphs, we all could understand. Instead, you post in these long-form rambling blocks of text that almost nobody could possibly care about. 'Tis terrible. I circumvent almost every post that is so unworthty of a sophomore english paper, that I find it so easy to skip one out of five posts. It's a forum - make a statement - back it up - and stand off. This Shakespearean crap bogs us all down and drains our intellects. Enough. Be succinct. Period. Stop it, you blowhards. FX
 
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Factor X    RE:wing loading/larryjcr   9/21/2005 12:41:18 AM
goddam, I guess it's useless. How much do I have to donate to get a forum that works in the technology of, say, 2001, or 2002. This is the weakest board I have ever enjoyed since 1997. Enough. I'll donate if I can see more than ONE feakin post per click. This 1999 crap just doesn't cut it anymore. Yech. Can we fix it, or should I abandon it? FX
 
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larryjcr    RE:Aargh! not shooters double entry bookkeeping again   9/21/2005 2:33:45 AM
to flamingknives: Interesting piece on the 20mm. Appearantly the failure rate wasn't high enough for Locheed to replace the P38s cannon with a couple more .50s, which would have been easy enough to do. On the other hand, six .50s in the nose was the ammament of the company's next effort, the P80.
 
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larryjcr    RE:wing loading/larryjcr   9/21/2005 2:35:19 AM
sorry about the lack of paragraphs. That is a weakness of mine. I'm aware of it and trying to improve.
 
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larryjcr    external loads   9/21/2005 3:22:21 AM
The Spitfire did use drop tanks. The RAF experimented with several models of different sizes and shapes and settled on one of about 55-60 (US) gal. Anything larger compromised handling qualities too seriously. The P51 usually carried two 108 gal. tanks The P47 often carried two 180 gal. tanks underwing, plus a 108 gal. on center. The P38 usually carried two tanks of either 250, or 300 gal. each. I made the comment about the P38 being experimentally loaded with torpedoes not to claim it did so in combat (it didn't) but to show that the a/c could carry well over 4000 pounds externally. This certainly degraded performance, but handling qualities of the a/c were still acceptable.
 
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oldbutnotwise    Shooter   9/21/2005 4:00:12 AM
a quick answer to a couple of your points. 1, you vastly over estimate what CGI was in the 40s, in the BOB british radar could tell you approximate poistion and ground controllers could get you with visual but to place you acurately on target was not something that could be done in 1940. it wasnt untill veitnam that cgi reaches the level your sugesting. 2, the 5" rocket was prototyped in 43 and in service 44 so how your p38 was using it in 42 is a bit strange I also got the wieghts of the same site. http://www.designation-systems.net/dusrm/app4/5in-rockets.html your points about the 20mm, yes the brits had problems with the gun in 1940, the breach was designed to be mounted on an engine block, wing mounting the gun created distortion in the feed mechnism jamming the gun, once this was overcome it became a very reliable weapon. I grant you i was wrong about the mkV in the mk14 spit it was the mk2 but the rate of fire of the UK gun was the same as the US the problem was the US gun was so unreliable
 
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oldbutnotwise    RE:external loads   9/21/2005 7:11:42 AM
yes it did, your corect however the usual tank was a 90 gallon slipper unit which was non dropable but was streamlined. the larger us tanks werent used because in tests they hit the wing on being dropped causing damange to the control surfaces, not a good idea.
 
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AussieEngineer    RE:Aargh! not shooters double entry bookkeeping again   9/21/2005 9:25:41 AM
http://www.spitfireperformance.com/ The MkXIV climbed faster than the MkIX particularly in a zoom climb, especially at full throttle. It climbed faster than any P-38. The MkIX could outclimb or at least match any P-38. OBNW>wrong, how do you get a minus boost figure? isnt that a vacuum? Actually, all aircraft operated with a sub atmospheric boost pressure at low power settings, including the P-38. The difference was in how the gauge measured boost pressure. American aircraft measured manifold pressure, or boost using absolute pressure. British aircraft measured it from a datum, which was atmospheric pressure. So 0 pounds boost is the same as 29.92 inHg. The P-38 flew between -1.5 to -8 pounds of boost at most economical power settings. So I don't know why shooter keeps banging on about -2 lbs boost, it is really nothing more than a red herring. Meanwhile he says figures from the pilots manual are fanciful. I have also shown conclusively that the MkXIV spit has a higher economical cruise speed than the lightning and suffers a comparitively smaller reduction at range when operating at cruise speeds greater than 300 mph. You yourself sitewd some Brit's claim of a kill at 600 yards I think you mean me not OBNW. You are definately taking what I've said previously out of context. I don't think I said kills, but being able to score hits, but that is also beside the point. I was demonstrating that accuracy at long range was a more a result of gyro-gunsights than weapon placement. They increased the kill/engagement by 100%. The gyro scopic gunsight allowed a fighter to score hits without being increadibly lucky at such ranges. Any aircraft is going to have great diffilculty trying to hit a target beyond 300 yards without a gyro gunsight. There was something in between 1300 and 1600 griffon engined spits in service during the war. The reason they didn't shoot many fighters early in their service was because they were tasked with intercepting V1s and flying ground support missions. I'm not sure when the first kill of a MkXIV was, but it was the first aircraft to shoot down an Me262. You should also remember that the P-38 took 9 months since it scored its first kill. Spitfire fuel tankage varied a fair bit from mark to mark and even within marks. The early marks only had about 80 gallons, but later MkIXs and XVIs had about 160 gallons of internal fuel, the FR XIV had 142 gallons. Some of the recon variants had over 300 gallons. Let us analise this claim; The P-38 could cruise at 360 MPH TAS for over two hours. The LATE MODEL Spit could Cruse at ~275 for almost 1-1/2 hours, but had no reserves if it did! That means to make a successfull attack, the Spit pilot had to select high throttle poss, accellerate to high speed and close on the target, BEFORE it could fire. Since that procedure required much more time than if the possitions were reversed, the Spitfire was much less likely to seek up unseen and kill the poor slob before he saw him comming. With the possitions reversed, the exact opposite is true. If we also look at if the target spotted the attacker, then the Mk-9 could never catch the faster P-38! (408 MPH to 414MPH!) If the positions were reversed, the Spitfire can not escape with out the P-38 pilot getting at least one shot at the turning Spitfire, before he disengages without possability of the Spitfire returnning the favor! It is impossable for the slower Spit to catch the faster plane. If we substitute the Mk-XIV Spitfire for the Mk-IX, then it is faster than the P-38 at HIGH throttle settings but is still slower at cruise! So if the target spots the attacker the Spit has a chance to escape, but not a large one as the P-38 guns will reach SIX times farther than the Spits guns. In reverse the Spit has an easier chance to catch the P-38 but not much. 360 mph is only achieved with settings for "emergency high speed cruising" only. That speed wouldn't be used under normal conditions. The P-38 is not likely to be cruising faster than 170-220 mph IAS. A fw190, bf109 or MkIX wouldn't have any trouble catching a P-38 if it was unaware. The climb of the spitfire, especially the MkXIV gives it a large advantage over most fighters. It allows the spit to choose when and how to disengage if it has to. It also allows it reduce the altitude advantage of enemy fighters. Many luftwaffe pilots were suprised when they thought they had successfully positioned themselves to bounce a MkXIV only to have them climb straight back up at them at high speed. The spitfire performed superbly when used in roles it was designed for and some it wasn't, something that can't be said for the P-38. A long range escort fighter it was not, but there was no need for one, even before the war the RAF planned to bomb at night not day.
 
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