Jabberwocky
Staff Sergeant
Nonskimmer said:But prepare to be swarmed by Spitfire fans.![]()
Well, I'm quite a Spitfire fan myself. British aircraft are, shall we say, my cup of tea. Bring them on, I love a good dogfight.
My last post left touching on the Merlin 61 engined Spitfire IX facing the 190A3 towards the end of 1942. The RAF had 4 squadrons fully operational with the IX by Dieppe and averaged about 2 squadrons converting to the newer version a month. Meanwhile the Luftwaffe operated 190A3/A4s and began to transition to 190A5 in mid 1943 with JG 2, JG 26 and maybe JG 56 (??) flying from France and Belgium.
By the end of April 1943 the 190A4 was in service and the 190A5 had entered production, improving the 'Butcher Bird' once again. The engine mounting was lengthened 15cm to reduce vibration and strenthen parts of the airframe. The Mw-50 Methanol/Water injection system also had a revised installation. The FW could now do approx 400-410 mph at 6000m with the Mw-50. Reports mention that there may of been a 2 minute operatonal limit imposed on Mw-50 in initial service, mostly due to overheating problems. This is contentious though as the manuals generally state 5 minutes or even ten minutes of operation per use. There was enough mixture for about 25 minutes of operation.
What the Mw-50 did was to significantly enhance the boost levels and speed of the 190, albeit for limited periods. The FW was now faster than ever, but weight creep was affecting its handeling, Kurt Tank actually developed a new wing for the A6 variant, to deal with the problem as well as to revise armament options. The 190 was always known for its very high stall speeds. It stalled at about 110-120 mph straight and level, compared to 70-80 mph in the same attitude for the Spitfire. In turns there was little if any warning of the vicious snap-stall that could develope. This made the 190 unsuited to traditional low speed dogfighting, Tank having realised that high speed would keep pilots alive better than sharp turns. Tank actually wanted higher wingloadings so that he could increase the speed of the 190.
In parallel with the improvements to the 190 the Spitifre was also seeing upgrades. Most noticably the Merlin 61 was fitted with an improved Bendix-Stromberg carburettor and other modifiactions and turned into the excellent Merlin 66/70/71 family. The Merlin 66 appeared about March 1943, alowing the Spitifire to increase its horsepower and boost levels in almost all regiemes of flight, as well as reducing crankcase loading with a heavier weighted crankshaft.
The Spitifre IX operating a Merlin 66 at +18lbs was between 15-20 mh faster below 11,000 feet than the Spitifre IX with a Merlin 61 at +16lbs. Up high there was very little difference in speeds, but down low the Sptifire was finally catching up with the 190. Its rate of climb was now much better at low altitude, particularly in the L.F. clipped wing versions of the Spitfire IX, which accounted for around half of all Merlin 66 production. Given how close the A3 had been to the Merlin 61 Spitfire IX in terms of low to medium level performance, the A4/A5 now had even less envelopes where it was ascendent. The RAF also deployed around 200 Merlin 70/71 high altitude versions of the Spitfire IX. It could reach around 415-418 mph at 27,000 feet, making it markedly better than the Fw190 above 20,000 feet.
Add to this the conversion of Spitfire V ariframes for lew level duties. The rather unkind epithat of "clipped, cropped and clapped" was added to them. Clipped, as in the wings, cropped as in the supercharger impellers were cut back for low alt usage and clapped, as in clapped out old airframes. However, these modifications turned the Spitfire V into a very useful low level fighter. Adding a Merlin 50M or 55M and running the engine at 18lbs boost meant that the formerly outclassed Spitfire V was now challenging the Fw190 at low altitudes.
Compared to a 'classic' Spitfire Vb/c with a Merlin 45/46 the L.F. version was a menace down low. With clipped wings and modified airframes (whip aerial, revised mirror rairings, removing the carburettor ice guard) it was up to 20 mph faster than the Vb/c on the deck. At full throttle height of 6000 feet a clipped L.F. V could make close around 350-360 mph. In 1943 some Spitfire Vbs also had their 'fishtail' type exhaust stubs replaced with multi-ejector stacks, the better aerodynamics and thrust generated by the new exhausts adding a further 5 mph down low.
With clipped wings a Spitfire V L.F. was only some 10-15 degrees per second slower in roll than a Fw-190. So, at the Fw-190s peak roll rate of about 165 degrees/second, the Spitifre was less than 10% slower in the roll. Only a few Allied fighters ever out rolled the 190, the P-38L with boosted alierons, the Mustang and Tempest are the only ones that come to mind, and even they only did so at high speed. At such low altitudes the traditiona FW flick over and dive was not effective and the FWs generally had to perform a shallow nose over followed by a serise of high speed zoom climbs to escape.
The little Spitfire V could now hope to compete with the 190A5 at low altitude. With a Merlin 50M the Spitfire climbed over 4,500 feet per minute until 5,000 feet and maintaned a 4,000 fpm climb until 10,000 feet. After this performance fell off rapidly however due to the cropped supercharger impeller on the M serise Merlins. With a Fw 190A4/A5 running at 1.42 ATA [highest cleared boost for the A5, used in mid 43 - early 44] the Spitfire V held roughly level pegging in speed from about 5,000 to 10,000 feet. Above or below these heights the Fw190 generally outran the Spitfire V but could not outclimb it at any height below 10,000 feet.
With the combination of Spitfire IX H.F. above 30,000 feet, Spitfire F/L.F. at 20,00 feet and Spitfire L.F. Vb/c at 5000-10000 feet the Spitfires now had the numbers and the all altitude abilities to deal with the 190 effectively.
More later, I'm just warming up to this. I knew there was a reason I had kept all the Rechelin and RAE reports on my HD!
![Shock :shock: :shock:](/forum/images/smilies/icon_eek.gif)