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I imagine the PR Spits went away pretty quickly as they certainly seemed to have a high attrition rate, at least in the Med. Not as bad as the Tac-R Hurricanes, but pretty bad. P-38 / F-4/5 recon planes too, very, very dangerous job. The Luftwaffe seemed to press far more resources into killing recon birds than to stopping bombers. It speaks to the importance of reconnaissance! The original military mission of aircraft.The RAF census as of February 1943 only has PR.III, IV. XI and XIII, with 30/30 III ordered/delivered, 229/232 IV, 152/31 XI (yes, more delivered than ordered) Nett conversions are 18 to III, 68 to IV and 4 to XIII. For June 1944 it is PR III, IV, X, XI, XIII, XIX and Spitfire PR (Griffon 66) with 30/30 III, 229/229 IV, 471/335 XI, 22/22 XIX and 229/0 Spitfire PR (Griffon 66) Nett conversions are 13 to III, 71 to IV, 16 to X, 25 to XIII.
Fascinating, but could the Mk.VII/VIII? While it had less fuel up front, it also had a heavier engine further forward, which might give it a center of gravity that would allow you to get away with stuff you couldn't do otherwise.The MkXIV could fight with the 90G combat tank fitted and outperform the Me109 and FW190 with it attached.
While I knew eventually mach effects would start to throw a monkey-wrench into that formula (almost always you'll never see something simple apply over a large array of conditions), I'm curious what correction factor is that?Trouble is that the cube root rule needs a correction factor once you get into the high 300mph range.
The Merlin 25 was a Merlin 24 that turned the opposite direction. It was rated at 9,250 feet.
The reversal of the rotation in the Merlin 131, 133 and 135 was achieved by use of an extra gear in the reduction gear casing. The crankshaft turned in the same direction as the Merlin 130, 132 & 134 and all other Merlins.No, the Merlin 25 had a "reversed flow cooling system". Though the actual internal flow was the same, the external cooling system was rearranged to suit the Mosquito's radiators.
The 25 turned the same way as most Merlins - the exceptions being engines like the 131 for the Hornet, which was the same as the 130 on the other wing but with reversed rotation.
No, the Merlin 25 had a "reversed flow cooling system". Though the actual internal flow was the same, the external cooling system was rearranged to suit the Mosquito's radiators.
The 25 turned the same way as most Merlins - the exceptions being engines like the 131 for the Hornet, which was the same as the 130 on the other wing but with reversed rotation.
The lion's part of the speed increase is the power increase. If a stock P-51 makes a 360 mph lap with 1,490 hp (pretty darn close to a stock P-51D lap) at Reno and makes NO OTHER changes other than bumping the power to 3,850 (can you say "Strega" or "Voodoo"?) the expected speed is 494 mph using the standard cube root rule. Voodoo's fastest lap is 512 with MOST in the 495 mph range, so all the little "extra" mods made a whole 18 mph bump after the 134 mpg bump that came from the power increase.
It didn't need too, there is more than enough space in the leading edge to increase the tank capacity from 26G to 50G, add 75G in the rear, 96G main and a 90G dropper and you have the range to fight deep over the continent.Fascinating, but could the Mk.VII/VIII? While it had less fuel up front, it also had a heavier engine further forward, which might give it a center of gravity that would allow you to get away with stuff you couldn't do otherwise.
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So the obvious streamlining, cut down canopy, blended joints and overall perfect fit and finish only added 18mph?.
Mach correction factor. The rough border between Incompressible Fluid and Compressible Fluid for aero is about M=0.3. Afterwards the Mach correction factor is applied to all Parasite and Form drag. 1/(1-M^2) is the multiplier. Refined in wind tunnel.Fascinating, but could the Mk.VII/VIII? While it had less fuel up front, it also had a heavier engine further forward, which might give it a center of gravity that would allow you to get away with stuff you couldn't do otherwise.
While I knew eventually mach effects would start to throw a monkey-wrench into that formula (almost always you'll never see something simple apply over a large array of conditions), I'm curious what correction factor is that?
All the power in the world is pointless without the aerodynamic improvements to go with it, the Spitfire's speed improved with every little mod, not much, 5mph here and there but add up a couple and the gains, as well as more power are worthwhile. To give an example the Seafire Mk111 was 12mph faster than the MkII just by deleting the cannon stubs, reducing the cannon bulges by half and changing from triple ejectors to individual fishtail exhausts.
The reversal of the rotation in the Merlin 131, 133 and 135 was achieved by use of an extra gear in the reduction gear casing. The crankshaft turned in the same direction as the Merlin 130, 132 & 134 and all other Merlins.
Well I think it is about fruit picking. Initially the quickest and cheapest way to make a P-51D go faster is to take all the guns and ammo out along with everything else you dont need, cover holes smooth and fill in gaps etc, but you can only do that once. The aerodynamic improvements have now been made, making a substantially better version than Voodoo would cost a fortune and is probably against the competition regs. All the low hanging fruit has been picked, only more power/thrust remains.Of all the changes you can make to go faster, power is far and away the biggest. If you believe streamlining is more important, stay away from Reno, which is the very temple of power changes.
So you'd cube root, then multiply by (1/(1-(M^2))? Or do you convert the airspeed to mach then do that?Mach correction factor. The rough border between Incompressible Fluid and Compressible Fluid for aero is about M=0.3. Afterwards the Mach correction factor is applied to all Parasite and Form drag. 1/(1-M^2) is the multiplier. Refined in wind tunnel.