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#11
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#12
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In article , WaltBJ
writes Slightly off track - the Germans did not seem to place the same level of importance on recce that the Brits and USAF did. Me109s could (some did) carry a camera in the aft fuselage like the recce P51s (F6?). A lightened waxed Me109F or G would have a very good chance of completing a recce pass on an in-and-out basis flown at max speed on a curving descent or in-and-out at naught feet (prop tips above the wave tips). It appears to me that the 86R was declared a 'clay pigeon' when the LW found out Spits and Mosquitoes, appropriately modifed, could get up that high. Why the LW didn't use 'hot-rodded' photofighters is beyond me. Maybe they swallowed the 'XX' turned spies' reports as gospel. Walt BJ Yes, the success of agents like 'Garbo' in feeding duff stuff to the German High Command was remarkable. Without wanting to go wildly off-topic, there was a programme on UK TV a few nights ago ('Spitfire Ace') that had some very useful stuff on the mentality of the RAF versus the that of Luftwaffe in 1940. The RAF (through the vision and efforts of Dowding) had created a parless air defence system, while the Luftwaffe had concentrated overmuch on the lionisation of its individual pilots. I think that by 1944 the Allies had developed a war machine that was thorough enough to filter out most flakey thinking and to concentrate on the real issues. If the Luftwaffe in 1944 was still relying on the whims of 'gifted individuals' (Hitler, Goering), who would have prided their own (uncriticised) judgement then a lot of bad ideas would have good through and a lot of good ideas would have been turned away. Cheers, Dave -- Dave Eadsforth |
#13
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In article , Keith Willshaw
writes "WaltBJ" wrote in message . com... Slightly off track - the Germans did not seem to place the same level of importance on recce that the Brits and USAF did. Me109s could (some did) carry a camera in the aft fuselage like the recce P51s (F6?). A lightened waxed Me109F or G would have a very good chance of completing a recce pass on an in-and-out basis flown at max speed on a curving descent or in-and-out at naught feet (prop tips above the wave tips). The Me-109G-8 recce variant had a camera in the aft fuselage and did conduct some photo recon missions over the channel area in 1944. Keith Hi Keith, Do you happen to know whether these were conducted at high level, low level, or the max speed altitude for the 109G-8? Cheers, Dave -- Dave Eadsforth |
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Dave Eadsforth wrote:
: Yes, the success of agents like 'Garbo' in feeding duff stuff to the : German High Command was remarkable. The familiar problem, as far as I know: Too many different intelligence services, every one a part of the personal empire of a different Nazi leader, and unwilling or unable to cooperate. And of course the 'Abwehr' leaked like a sieve. The Germans did produce recce versions of fighters, usually with fewer guns and more fuel; in addition to cameras of course. But I suspect the Bf 109 was just less adaptable to the task than the Spitfire. It was even smaller. The Spitfire had inherited a D-shaped leading edge structure from its direct ancestor, the Supermarine 227, which used this as a condensor for its steam-cooled Goshawk engine. This made a great fuel tank for the long-range reconnaissance versions. With better fuel and more powerful engines, these models could also operate at higher weights and reach higher altitudes than Bf 109s. On the other hand Ju 88s were less suitable for reconnaissance than Mosquitoes, because they were bigger and slower. Still, the Germans did develop a high-performance recce aircraft in the Ar 234A. Emmanuel Gustin |
#16
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Others have already hit on what effect higher octane ratings had. Peter
Stickney will probably have one of his great replies coming along soon too. But here is a quick rundown on what 104/150 octane should provide for a Merlin 266. The US had an empirical formula for calculating MAP limits at different PN. It is a little conservative, but gives a good ballpark figure. ((old MAP -7) * new PN/old PN) +7 = new MAP So, 66.6 in Hg on 100/130 octane would give: ((66.6 - 7) * 150/130) +7 59.6 * 1.154 + 7 = 75.76 in Hg The RAF actually used +25 psi, about 80.9 inches. We know the Merlin 266 was rated at 66.6 in Hg, 1705 hp @ 5750 ft in low blower. That is enough information to approximate how much power the engine provides at any altitude. We also know static pressure at 5750 ft is approx 24.20 in Hg. So, dividing 66.6 by 24.20 gives us approx 2.75 for the pressure ratio that the Merlin 266 provides in low blower. Multiplying static pressure by the pressure ratio gives the manifold pressure available at any altitude. 80.9 in Hg would be attainable up to about 500 ft unrammed, and approx 82.4 in Hg at SL. Since we know it produces 1705 hp @ 66.6 in Hg we can figure how much it makes at 80.9 in Hg. 1705 * 80/66.6 gives about 2071 hp. Then you have to take the difference in temp into account. Sqrt of absolute temp at 5750 ft / absolute temp at 500 ft times 2071 hp. (sqrt (276.86 / 287.36)) * 2071 = 2032 hp @ 500 ft. (I'm using the 1976 standard atmosphere for all calculations, older atmosphere models might provide slightly different figures) This should be accurate +- about 1%. You can do the same thing for just about any engine, provided you have an accurate base altitude, power and MAP rating to start with. I cheated and created an Excel spreadsheet that does all the work for me. You need to make sure and use static ratings, a lot of RAF ratings are with 350 or 400 mph RAM which will screw things up. RAM will cause a higher rated altitude from the ram pressure, but lower power due to compression heating. Greg Shaw |
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#18
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Dave Eadsforth wrote in message ...
In article , WaltBJ writes Slightly off track - the Germans did not seem to place the same level of importance on recce that the Brits and USAF did. Me109s could (some did) carry a camera in the aft fuselage like the recce P51s (F6?). A lightened waxed Me109F or G would have a very good chance of completing a recce pass on an in-and-out basis flown at max speed on a curving descent or in-and-out at naught feet (prop tips above the wave tips). It appears to me that the 86R was declared a 'clay pigeon' when the LW found out Spits and Mosquitoes, appropriately modifed, could get up that high. Why the LW didn't use 'hot-rodded' photofighters is beyond me. Maybe they swallowed the 'XX' turned spies' reports as gospel. Walt BJ Yes, the success of agents like 'Garbo' in feeding duff stuff to the German High Command was remarkable. Without wanting to go wildly off-topic, there was a programme on UK TV a few nights ago ('Spitfire Ace') that had some very useful stuff on the mentality of the RAF versus the that of Luftwaffe in 1940. The RAF (through the vision and efforts of Dowding) had created a parless air defence system, while the Luftwaffe had concentrated overmuch on the lionisation of its individual pilots. Honestly this sounds like Brits patting themselves on the back while not looking at the strategic and tactical issues the Germans faced. (sadly this is a sort of anasthetic as the UK goes down a sewer) I think that by 1944 the Allies had developed a war machine that was thorough enough to filter out most flakey thinking and to concentrate on the real issues. If the Luftwaffe in 1944 was still relying on the whims of 'gifted individuals' (Hitler, Goering), who would have prided their own (uncriticised) judgement then a lot of bad ideas would have good through and a lot of good ideas would have been turned away. German thinking was predicated on the need to fight a short and sharp war as a nation sourunded by hostile countries. Avoiding a war of attrition was essential and avoiding a war on German territory was also essential. The nation was physically to small and to devoid of materials to handle a war in any other way and not loose thus substantial offensive capability was emphasised but it was all up front: resources were not devoted to reinforcements. This was the thinking even before the Nazis came to power. Much of the German work on Microwaves and Proximity fuses (which inspired British research) was suspended because the anything that could not be ready in 2 years would be a waste. It seems that at this point that many of the German might have beens got caned. Examination of this period is perhaps where it might be said that Germany's technical may be said to lie. It migh also just lay in the fact that Germany lacked the resources to develop them. The Tiazard commision handed the proximity fuse and magnetron on a platter for the USA to develop. The Germans just culled. The excelent Freya and Wurzburg Radars were not integrated into a defensive system because the bomber naviagation aids were considered more important. Cheers, Dave |
#19
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In article , The
Enlightenment writes (Peter Stickney) wrote in message news:dbocvb- ... In article , Dave Eadsforth writes: SNIP of repeated material Nitrous oxide was more a technique the Germans were forced into to help overcome a German disadvantage in high octane or high test aviation fuels rather than a paucity in thingking. The Germans did have techniques for manufacturing octane and even higher knock hydrocarbons their technology was however more cumberson than the US technology and this limited their production rate. Why this was I don't know. It may have had something to do with the fact that they had access to only snythetic oils from fischer tropsch and hydrogenation plants or their own small crude oil industry or Romania's all of which are regarded as poor quality crudes. (California crude was rather highly regarded). It may have just been that they were unaware of the US techniques. Nitprous oxide also was used only at higher altitudes: water methanol injection was used at low altitude. The Ta 152H has a watern methanol and nitorous oxide system. The clipped wing Ta 152C has only water methanol for its BB603LA The Jumo 213E had a two stage 3 speed supercharger WITH an induction cooler. It still had water methanol and nitorus oxide (nickamed HA HA system because Nitorus oxide was laughting gas) Ta 152H Engine: Junkers Jumo 213E-1 twelve-cylinder liquid-cooled engine rated at 1750 hp for takeoff (2050 hp with MW 50 boost) and 1320 hp at 32,800 feet (1740 feet with GM 1 boost). Maximum speed: 332 mph at sea level (350 mph with MW 50 boost), 465 mph at 29,530 feet with MW 50 boost, 472 mph at 41,010 feet with GM 1 boost. Service ceiling was 48,550 feet with GM 1 boost. Initial climb rate was 3445 feet/minute with MW 50 boost. Weights were 8642 pounds empty, 10,472 pounds normal loaded, 11,502 pounds maximum. Wingspan 47 feet 41/2 inches, length 35 feet 1 2/3 inches, height 11 feet 0 1/4 inches, wing area 250.8 square feet. The Ta 152C-1 was powered by a Daimler-Benz DB 603LA twelve-cylinder liquid cooled engine rated at 2100 hp (2300 hp with MW 50) for takeoff and 1750 hp at 29,530 feet (1900 hp at 27,560 feet with MW 50). Armed with one engine-mounted 30-mm MK 108 cannon with 90 rounds, two fuselage-mounted 20-mm MG 151 cannon with 250 rpg, and two wing-mounted 20-mm MG252 cannon with 175 rpg. Maximum speed was 227 mph at sea level (356 mph with MW 50), 436 mph at 37,730 feet (460 mph at 32,810 feet with MW 50). Initial climb rate was 3050 feet per minute and service ceiling was 40,350 feet. Weights were 8849 lbs empty, 10,658 lbs normal loaded, and 11,733 pounds maximum. Wingspan was 36 feet 1 inch, length was 35 feet 6 1/2 inches, height was 11 feet 1 inch, and wing area was 290.89 square feet. Thanks for this very useful summary - very much appreciated. Cheers, Dave -- Dave Eadsforth |
#20
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In article , The
Enlightenment writes Dave Eadsforth wrote in message news:s9BISHBVA3GAFw82 ... In article , WaltBJ writes Slightly off track - the Germans did not seem to place the same level of importance on recce that the Brits and USAF did. Me109s could (some did) carry a camera in the aft fuselage like the recce P51s (F6?). A lightened waxed Me109F or G would have a very good chance of completing a recce pass on an in-and-out basis flown at max speed on a curving descent or in-and-out at naught feet (prop tips above the wave tips). It appears to me that the 86R was declared a 'clay pigeon' when the LW found out Spits and Mosquitoes, appropriately modifed, could get up that high. Why the LW didn't use 'hot-rodded' photofighters is beyond me. Maybe they swallowed the 'XX' turned spies' reports as gospel. Walt BJ Yes, the success of agents like 'Garbo' in feeding duff stuff to the German High Command was remarkable. Without wanting to go wildly off-topic, there was a programme on UK TV a few nights ago ('Spitfire Ace') that had some very useful stuff on the mentality of the RAF versus the that of Luftwaffe in 1940. The RAF (through the vision and efforts of Dowding) had created a parless air defence system, while the Luftwaffe had concentrated overmuch on the lionisation of its individual pilots. Honestly this sounds like Brits patting themselves on the back while not looking at the strategic and tactical issues the Germans faced. (sadly this is a sort of anasthetic as the UK goes down a sewer) While I agree that we, as a nation, should be organising our lives better these days, there is no doubt that the British air defence system of 1940 was unmatched anywhere else in the world, and no-one, not even the Germans, dare to claim that Goering's boasts of 1940 held water. I think that by 1944 the Allies had developed a war machine that was thorough enough to filter out most flakey thinking and to concentrate on the real issues. If the Luftwaffe in 1944 was still relying on the whims of 'gifted individuals' (Hitler, Goering), who would have prided their own (uncriticised) judgement then a lot of bad ideas would have good through and a lot of good ideas would have been turned away. German thinking was predicated on the need to fight a short and sharp war as a nation sourunded by hostile countries. Avoiding a war of attrition was essential and avoiding a war on German territory was also essential. The surrounding countries were only hostile because of Hitler's belligerence - he could have been a peaceful leader had he so chosen. As for laying odds on a short war - having contingency plans in case your lightning strike does not work is fundamental to military planning. The nation was physically to small and to devoid of materials to handle a war in any other way and not loose thus substantial offensive capability was emphasised but it was all up front: resources were not devoted to reinforcements. This was the thinking even before the Nazis came to power. Germany had many resources to spare in the early years of the war. Their industry was still working single shifts until things got really bad. While Hitler was telling the German people about how well things were going, Churchill was telling the British that we had to get a wiggle on or lose - and our industry went to 100 percent from 1940 onwards. Much of the German work on Microwaves and Proximity fuses (which inspired British research) Um...they told us about their work in these fields? was suspended because the anything that could not be ready in 2 years would be a waste. Not a waste, a strategic error - no-one to blame but themselves. It seems that at this point that many of the German might have beens got caned. Examination of this period is perhaps where it might be said that Germany's technical may be said to lie. It migh also just lay in the fact that Germany lacked the resources to develop them. Poor prioritization - no-one to blame but themselves. The proximity fuse was a small printed circuit that any small group of radio men could have taken forward - there was no great industrial effort needed here. The Tiazard commision handed the proximity fuse and magnetron on a platter for the USA to develop. The Germans just culled. Good prioritisation on Tizard's part - hand the designs over to the people who can mass produce immediately. The excelent Freya and Wurzburg Radars were not integrated into a defensive system because the bomber naviagation aids were considered more important. Integration was a matter laying telephone connections and training a limited number of staff. If you have started a war, and it has gone pear-shaped, and your efforts have simply created a hostile world around you, air defence should then be recognised as a priority. After 1942 the allies were no longer fighting a war dictated by German initiatives - they were fighting according to their own. Cheers, Dave -- Dave Eadsforth |
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