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My question is: Would the most likely, IE "realistic" engagements between a Spit and a K occur with the Spit in the bottom half of it's fuel load, giving it a larger performance advantage? [...]
My goal here is to establish what "most likely" occurred or would have occurred.
Cheers,
Biff
Can I ask if anyone has a translation of the last part as its not oftgen you get the German view
Can I ask if anyone has a translation of the last part as its not oftgen you get the German view
There are two aspects of this comparison and that is the handling and the weight involved in delivering the extra power to the aircraft. The Me109 may well have the speed but it relied on a different tank of fuel that for most of the flight was just extra weight. What would be interesting is what is the climb and acceleration with max power but without the extra boost. I would expect the Spit to have a better performance without the boost
While both only have a limited time of extra power the Spits didn't involve the extra tank and plumbing. Also of course if in a tight corner the Spit could ignore the time limit and buy the ground crew a few rounds in the bar as an apology.
The second aspect is the handling. Both fighters get heavier on the controls with speed but the 109 was very bad at speed and this alone is a major problem
Almost whatever the situation I would expect the XIVe to have the advantage as the 109K was very heavy on the controls at high speed, most tests of the 109G that I have seen use phrases such as almost solid, very heavy. The reason for the K was to get to the higher speeds which is where it was at its weakest.
The problem for the K is that the Spit was always the more agile even at slower speeds and was better in the climb. The only real advantage to the K was its dive which may help escape trouble but you had better find a cloud because when you reach the ground the K is back to square one again.
Its also interesting to take into account that the equivalent in development terms to the 109K is probably the Spit 21 which had a number of improvements which would have a significant advantage in performance and handling.
Furthermore we know the Me 109K4 had a modified wing
With the anniversary of the BoB there have been a lot of coverage. One old veteran BoB Hurricane pilot said as long as he saw the enemy he always felt he could deal with it. Bungays history of the BoB also says that the massed dogfights were inconclusive, once both sides were engaged (not bounced) the pilots were more concerned looking behind than in front so kills were as much dependent on luck as skill. 1 on 1 a hurricane was at a severe disadvantage against the 109 because it was slower and so couldnt break away, that doesnt mean it was a sitting duck, if caught 1 on 1 over England the pilot always knew his adversary had to break off to get home so he could play for a draw.Some think if you say something wasn't "as good as" another something, you are trashing it. Nothing could be further from the truth. Neither of the main German fighters was a "bad" fighter. They had their strong points and weak points, just like Allied fighters did. A well-flown Bf 109 was a serious threat to anything it encountered. The same can be said of a well-flown Yak-3, Hurricane, etc.
... The Me 109K14 with the two stage supercharger on the DB605L engine unlikely to have suffered any altitude disadvantage and may have superiority as its speed at 1.75ata and with a 4 blade prop was to be 453mph.
In terms of roll rate we have little information. The little data we have is of chart of a Me 109G6 roll rate at 30kg stick force shows its roll rate about equal to the Mk IX with full wing tips when at high speed.
... Tests in which the aileron deflection per 50lb stick force of the Spitfire is shown to be greater than the Me 109G can be disregarded as a factoid for comparison purposes as they do not take into account the Spitfires slightly greater wing aero elasticity. These measurements were a case of British engineers attempting to understand a different design by breaking it down into its components.
Furthermore we know the Me 109K4 had a modified wing and this might translate to improved roll rate, it would be wrong to assume that the K4 simply had the same wing as the G6. Some Me 109G6 were made by by licence producer of Me 109's WNF with spring tabs on the ailerons clearly to improve high speed roll rate. Drawings exist of Me 109K4 with spring tables on the ailerons so the intention was there. Given the state of the war one can imagine that it was hard to introduce such a new mechanism.
This would eliminate the supposed higher stick forces though as the Me 109 had a relatively torsionally stiff wing so 'stiff' ailerons doesn't necessarily translate to low roll rate. The Me 109 wing spar was around the 50% of chord mark not 25% or so of the spitfire.
Tabs of various types were used in an number of late war high speed aircraft to reduce control surface loads. They were common on bombers but started to appear on late war Corsairs, Hellcats, Arado 234 and indeed the Spitfire 21 had aileron balance tabs and it was surely not beyond the German industry to introduce these in mass as well.
The Me 109K6, Me 109K14 all would have received Mk108 canon integrated into the wings rather than fitted in gondolas underneath. Hence with 3 x Mk 108 30mm guns and 2 x MG131 13.2mm guns the aircraft was well armed. This gun was lighter than any 20mm guns, even the short barrelled Hispanos used in Spitfires (24 series).
We would also need to consider the possibility of the development of an advanced fuel equal or close to equal to allied 150PN or US 115/145 boosting power of the DB605L into the 2000-2200hp territory.
The Me 109 was still competitive to the very end even though the Germans were keen to replace it.
In terms of fuel the Spitfire VIII and XIV had 95 Imp Gallons in the area between the engine and cockpit with additional leading edge wing tanks that increased internal fuel to 120 Imperial gallons. Only the bottom tank was protected. This is 501.6 Litres of fuel. The Me 109K4 had 400L in a tank behind and underneath the pilot with an additional 86 litres for the MW50 tank. The Me 109K4 with the appropriate engine and fuel setup (DB605DB/DC) could fly a mission on approximately 1.8 ata boost on either B4+MW50 or an all C3 fuel mission by filling of the supplementary tank with C3. In this case the difference between 501.6L and 486L is only 2.9%. I doubt there was any difference in range considering the Griffon was a much heavier engine (both the single stage and duel stage intercooled Griffons were much heavier). The Mk XIV clearly had a very short range and even in the non teardrop versions the use of a tail tank was only for special missions and required permission. It's stability issues were such that its combat mission usefulness can be completely discounted. When the short range of the Me 109 is quoted (360miles for the K4) it should be noted this is a maximum cruise speed of nearly 350-380mph.
The 1.8 ata Me 109K4 seems faster than the Mk XIV at most altitudes below 22,500ft and the XIV developed a consistent superiority only above that altitude, this applies to both the 18psig and 21psig boost Griffons. The Me 109K14 with the two stage supercharger on the DB605L engine unlikely to have suffered any altitude disadvantage and may have superiority as its speed at 1.75ata and with a 4 blade prop was to be 453mph.
The Me 109K6, Me 109K14 all would have received Mk108 canon integrated into the wings rather than fitted in gondolas underneath. Hence with 3 x Mk 108 30mm guns and 2 x MG131 13.2mm guns the aircraft was well armed. This gun was lighter than any 20mm guns, even the short barrelled Hispanos used in Spitfires (24 series).
We would also need to consider the possibility of the development of an advanced fuel equal or close to equal to allied 150PN or US 115/145 boosting power of the DB605L into the 2000-2200hp territory.
The Me 109 was still competitive to the very end even though the Germans were keen to replace it.
There is no doubt that any DB 605 was more frugal with fuel than any Griffon; the DB 605 was already more frugal than Merlin. Quirk with Spitfire is that 170 imp gal (773 L) drop tank was available from mid-war on, and that, combined with rear tanks was bound to give considerable range/radius. Spitfire XIV cruised at 360 mph on 'max weal mixture'.
The "its combat mission usefulness can be completely discounted" statement will need backing up from a good source, we know that RAF was not fond with Mustang's fuselage tanks (another less-than-ideal solution that worked), that USAF used regularly.
The K14 will have less power at lower altitude than K4, some 200-300 PS deficit, when both aircraft are using C3+MW 50; situation reverses from some 7 km up. Granted, the entire two stage program in Germany in ww2 lagged 18-20 months to be of any use.
With K14 and it's two-stage DB 605L, had it reached service, the rear tank is mandatory filled with MW 50, since it was necessary with both 1.75 ata @ 2800 rpm (Notleistung) and with 1.43 ata @ 2600 rpm (Kampleistung), due to the lack of intercooler and too high a compression ratio. With only 400 L in the K14, the Spitfire 21 or 24, or Spiteful, will have a superior range/radius.
Of course the MG 131 was lighter than 20 mm cannons, the 20 mm sported far greater firepower. Quirk with integral MK 108 is that it never left the mock-up stage. We can compare that (or not) with Spitfire actually having 4 cannons.
The late war German C3 fuel was already between Allied 130 and 150 PN fuel, not much will it gain with 'straight' 150 PN fuel. Decrease the compression ratio and/or install the intercooler and engine will withstand greater boost (for more power).
Very true.
page 13 rich mixture rating 116% and 120% of US 130 grade
http://www.fischer-tropsch.org/Tom Reels/Linked/A5464/A5464-0638-0654 Item 6A.pdf