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Bill - the 51 had excellent acceleration and compared well with the P-38 and F-4U on the US side despite their much higher horsepower (and gross weight). Reduced drag and perhaps combined exhaust thrust and Meridith effect may have contibuted significanty to its acceleration performance to other fighters with better Hp/weight ratios.
Additionally drag comparisons must be looked at very closely as this is one of the key reasons the 51 was so fast, particularly at altitude..
we obviously have a communication problem here, first Reschke has errors all through his work which I am trying to correct. Second yes the Jg 51 component unit was the high altitude staffel and made up the 4th staffel-special in JG 302
as to Jg 302 becoming the so-called III./JG 301 the JG 302 pilots became idol in other words they did nothing except fopr a paper transfer into JG 301. JG 301 did not receive any Fw 190A's till September and then they and the other two gruppen were able to fly individually as well as a 3 gruppen Geschwader practicing Sturm like tactics.
Klar ? Knegel my cousin was a pilot in 5./JG 301 in November of 44.
Bill - I am confused why you would extract a performance comparison from a USN report which has the P-51D-5 operating at 62" (WEP) and 3000 rpm when the spec 51D-5 w/1650-7 Merlin was 75" hg for WEP?Drag is lower across the board for every aircraft at higher altitudes. What made the 51 fast was its high altitude engine performance.
Ah, No. What made the 51 fast is the combination of VERY low drag compared to Spitfire, Fw 190A, Me 109, P-47, F4-U, F6F, P-38 and an Adequate amount of horsepower combined with positive (theoretically) thrust via Meridith effect. The P-51H for example which was the same drag as the B/C/D but had a 1650-9 with up to 2200 hp at 90" was both very fast and very good acceleration because it had very low drag AND a very powerful engine
http://www.wwiiaircraftperformance.org/japan/zeke52-taic38.pdf
Note the date of the USN report and the reported Boost/rpm for each fighter tested
Level flight acceleration from 190IAS at 25,000ft using the Zeke 52 as a baseline aircraft:
Lead after one minute:
P-51D 300 yard at 62" versus 75" WEP
P-38J 250 yard P-38 fairly close to potential
P-47D 400 yard at 64" versus 70" WEP
Lead after two minutes:
P-51D 1000 yard Ditto
P-38J 500 yards
P-47D 800 yards
It retains a similar performance gap at 10,000ft, where most of the P-51s speed is seen after a minute of flight.
I think if pilots wanted to get going fast they would utilize a shallow dive, so this is not typical of a combat situation but it does illustrate the point about acceleration.
Its one of those designs that utilizes a low drag profile more so than a high powered engine, not that 1695 is a shabby number of horses.
Bill - it uses the engine with the max hp for the envelope available to it (the P-51). The Hp available grew from 1600@67" (-3) to 1720@67" (-7) to 1800+@75" (-7) to 2270@90" (-9)
The (-7) in the P-51B was slightly lighter than the P-51H with the (-9) so the growth in Hp from the P-51H over the P-51B at max boost was ~ 2270/1800 = 1.26
The (-7) had approx 1490hp@62" and 1800hp@75" for a ratio of 1.20 - so the USN compared the acceleration with an engine performing leas than 85% of potential?
Bill
Hi,
75HG was only allowed when 150 octan fuel was available, otherwise 67HG was WEP. There are some documents that say the 8th airforce used that fuel from June44 onward, while there are docus that claim that US units on the continent(9th airforce ??) dont use this fuel.
There are documents as well as living first hand accounts. The 355th FG got its first delivery of 150 octane (as well as all of 8th FC) in mid to late June, 1944.
'Others' didn't use the fuel because a.) production was not high enough to supply all units - so it was prioritized
Like so often P51 is just not = P51. We also still dont know how many C3 fuel the 109´s could use. Clear is that WEP is what it is, its not Combat or Military rating and will decrease the range a lot.
True - but the P-51B/C and D and H all used 150 octane fuel in the 1650-7 and -9 Merlin engines and the use of WEP enhanced performance for the 5-10 minutes allowed. This fuel and enhanced performance was available from June 44 through April 45
We also dont know the exact power output of the Jumo213A, this also seamed to change. We also dont know how many Jumo powered 190´s was adjusted for low level(Boden Lader) or how many did use C3 fuel(common fuel in the FW units).
Which plane was better just did depend to the altitude, what it should do, the used fuel, possible boost setting and time of usage of this boost. The 190D was the better ground attacker, the P51 the better high alt and escort fighter(>6500m), the 190D had a little better guns and they was more centered as well. Over Europe it wasnt a big different between the fighter performences, some times one side, some times the other side had a smal advantage. Against Japan it was much different, where already the P38G was like the 262 over europe and where the P40 was like a 109 vs Ratas. At the end not the planes or pilots won, rather the overwhelming masses of the Allieds in the west and east, where the red army most probably would have won the war alone.
You think if USSR fought the war alone it would have prevailed? that Germany would not a.) use Sarin and b.) develop nuclear weapon in time to be decisive with no attacks on German industry, no battles in west to divert resources, no supplies from US and GB?
Its increcible to see that the Ki43 and also the A6m was the backbone of the IJNA and IJAA till the end of war. Thats like using the SpitIa or 109E4 but without protection in 1944. Even the Ki66 was not much more than a 109F2 with better guns.
Greetings,
Knegel
The 51s w/1650-7 were operating initially (apr 44) at 67" WEP and at 75" WEP (June 44).
Knegel - the US did not have 'overwhelming' air superiority in numbers of strategic fighters until perhaps Dec 1944 and certainly after Bodenplatte.
The US did have a much better supply of new pilots to introduce to the MTO and ETO in 1943, the LW failed to strike at US fighters and thus permitted the 8th AF FC to grow in confidence and experience - to develop the tactics and the leadership which was able to lead new pilots entering battle more effectively.
Remember the P-47 didn't have the range to go to east germany until summer 1944. The P-38 only achieved four active groups and the last one came in when the first 38 group was converting to Mustangs.
The Mustang groups number 1 in Dec 43, 3 in Feb 1944, 5 in March, 6 in April and 7 in may.
It wasn't until April the the 8th AF could protect 500 bombers of one Bomb Division (out of three) with two long range escort Groups and to cover that would spread six squadrons with many mechanical problems early to net ~ 75 to 80 fighters to protect against twice that number or more LW fighters directed by the controllers.
The LW was always able to concentrate 200 to 300 of LuftFlotte Reich in a small region to attcke with local superiority. It was the battles from February through May that broke the back of the LW over Germany - with Mustangs primarily. There were several 8th AF FG's that scored more aircraft destroyed in the air than all the 8th AF lightning groups combined.
Was this 72" just a temporary boost level while transitioning to the P-51?
What is the corresponding boost for 75" in the British system?
If the fighters was there, they had in most cases the higher number than the few german topcover units, in many cases nothing more than one Schwarm.
Otherwise they just had to disturb the initial concentrated attack to the bombers, against single attacks the Bombers could hold its own rather successfull.
Most german fighters from late 1943 onward actually cant be seen as fighters, they was armned and protected and as such did perform rather as destroyers(109 with gunpods, rocket tubes, extra amor, 190´s with many extra guns or extreme heavy guns).
Like you say, they forgot about the fighters, the few fighters and here i still talk bout the top cover units(clean 109´s in that case), which was in theory able to make combat on even terms, was badly outnumbered.
Greetings,
Knegel
Good enough means that the 109G with a good pilot could handle the P51B/D, specialy in altitudes around 6-8000m. I agree, the lost of initiative was the main problem. They had to attack the bombers and while attacking the bombers they often lost their wingis, as result they fought alone in a tactical bad position.
Hi,
75HG was only allowed when 150 octan fuel was available, otherwise 67HG was WEP. There are some documents that say the 8th airforce used that fuel from June44 onward, while there are docus that claim that US units on the continent(9th airforce ??) dont use this fuel.
Clear is that WEP is what it is, its not Combat or Military rating and will decrease the range a lot.
Which plane was better just did depend to the altitude, what it should do, the used fuel, possible boost setting and time of usage of this boost. The 190D was the better ground attacker, the P51 the better high alt and escort fighter(>6500m), the 190D had a little better guns and they was more centered as well. Over Europe it wasnt a big different between the fighter performences, some times one side, some times the other side had a smal advantage.
Against Japan it was much different, where already the P38G was like the 262 over europe and where the P40 was like a 109 vs Ratas. At the end not the planes or pilots won, rather the overwhelming masses of the Allieds in the west and east, where the red army most probably would have won the war alone.
Its increcible to see that the Ki43 and also the A6m was the backbone of the IJNA and IJAA till the end of war. Thats like using the SpitIa or 109E4 but without protection in 1944. Even the Ki66 was not much more than a 109F2 with better guns.
To put it shortly, P-51D could have done anything D-9 could, while vice-versa was not possible.