Aces High Bulletin Board
General Forums => Aircraft and Vehicles => Topic started by: Lumpy on May 13, 2008, 04:24:39 AM
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Serenity ... not wanting to rain you your parade or anything, but in real life the Allies had better performance late in the war than they do in AH. The performance of the P-51 and P-47 in AH is comparable to early 1944, so in AH the 109K-4 has an unhistorical advantage in engine power. In AH the P-51D is limited to +18 lbs of WEP boost producing ~1,700 hp, but in late 1944/early 1945 the Ponies had a maximum WEP of +22(point something) producing almost 2,000 hp.
Of course the 109K-4 is also limited to using B4 fuel giving it only ~1,800 hp, but most 109K's probably flew on B4 due to logistical reasons (would be fun to have C3 fuel available as a perk option though!).
So in AH I agree with you: I'd take a 109K-4 over the Pony any day. However in real life it was not as clear cut.
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Is my memory getting flaky, - didn't the Mustang end up with 27 boost? Well, maybe I'm mixing it up with the other scale, - mm.hg?
In any case, we don't have the uber-mustang. And in RL, the DB (AFAIK) suffered from wear much sooner than a Merlin, - loss of power that is. So, AH does not exactly present the 1945 setup as it was in RL on a daily basis.
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I think anyone attempting to duplicate the historical superiority of U.S. aircraft in WWII will find themselves dissapointed. Given that range and altitude performance don't really matter in the 6,000 foot furball, IMO, U.S. aircraft are handicapped compared to Russian designs especially, and the late British aircraft. In real life, I wouldn't have traded a P-47, P-51, F6F, F4U or P-38 for any other ride available.
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Well, there are many little things in aircraft construction, handling and lifetime etc that do not stick out in AH.
As well as the fact as the US birds really shone at altitudes we rarely see in AH. In TOD this will however be the case.
And naming some birds for high alt....the Spittie, hehe.
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to me 2 things stick out that make the US aircraft better in WWII than AH. OR rather, make the german aircraft poorer.
1. Altitudes of the fight in WWII were much higher than most furballs in AH (guarding bombers @ 30K).
2. The quality of the fuel for the germans was fairly poor during the late war, handicapping performance gains of the later model german aircraft.
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2. The quality of the fuel for the germans was fairly poor during the late war, handicapping performance gains of the later model german aircraft.
Explain please.
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As far as I've understood (and i'm no expert). Refinery infrastructure was hit heavily in Mid War Europe and the germans had less availability of high quality avgas for their aircraft. I know the 109 could operate on fairly poor fuel at the expense of reduced performance. It is very possible that 109s operating on lower quality fuel would face a performance disadvantage. (now where I am more of an expert) At the higher boost levels an engine is required to operate at high altitudes, high octane gas is a critical factor. Reduced boost levels have a far more drastic effect up high as opposed to down low.
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Hmm, we had luftwobbles explaining the superior quality of the LW stock as well as quantity. but, that's...them.
They did get really low in quantity in the end, and AFAIK as well in quality, or availability of the right stuff.
They also had problems with engine durability, i.e. power loss due to wear and tear which has been claimed to occure within very few hours. LW aces as Rall have mentioned this after testing captured allied aircraft. Well, maybe this had something to do with boosting...MW and such, or lack of some material for engine building, - many opinions on that.
But the fact remains...the Western Allies took over the very high alt performance as soon as the Spit IX entered the game in 1942, and held it for the next couple of years, beyond the line when it was clear that the Axis would loose.
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I think the real difference came in pilots. Germany had the equipment as far as aircraft goes, but they didn't have experienced pilots left to really take on the American air forces.
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1942+ to 1944 the Allies held the cards at really high alt. Such as high cover for bombers. So the German interceptors would have to go in for a slash, and make that count to one before going for the deck, if there was escorts.
However, the Allies had to fly for HOURS over axis held territory, so them slashes ended up counting....
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"Hmm, we had luftwobbles explaining the superior quality of the LW stock as well as quantity. but, that's...them."
well, if you are talking about C3 fuel the point probably was that the pressure performance was better than the octane rating would indicate.
I found this, altough I'm not sure if it is 100% correct but it presents another view on the subject:
http://www.efdlk.com/Auto/gasoline.htm
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Not a bad over view Charge. Thanks.
But:
However, German aviation engines were of the direct-fuel-injection type, and could use methanol-water injection and nitrous oxide injection, which gave 50% more engine power for five minutes of dogfight.
The Allies used ADI, aka MW50, and NO2. Iirc some Mossies used NO2. The 50% increase in engine power is a bit of an exaggeration.
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Mossie on steroids? That would explain some of their performance legend!
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"The 50% increase in engine power is a bit of an exaggeration.
Yeah, I don't know where people get this kind of figures and why they put them up as facts. To anybody who knows about engines the 50% figure should look a bit suspicious.
There is a document about allies analyzing German avgas properties but I could not find it. IIRC the rich mixture octane rating was considered too in that document but I don't recall it being as good as 130 octane fuel.
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A couple of links I have Charge
http://www.fischer-tropsch.org/Tom%20Reels/Linked/A5464/A5464-0638-0654%20Item%206A.pdf
http://www.fischer-tropsch.org/primary_documents/gvt_reports/USNAVY/tech_rpt_145_45/rpt_145_45_sec2.htm#Composition%20and%20Specifications
Got to thinking afterwards. What was the power output at altitude? If NO2 was used, I have seen a 2-300hp gain. Still not 50%, I would suspect.
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It would never be 50% just on that.
Bear in mind though that the power extracted out of a modded RR Merlin running on "cocktails" in the production built "Speed Spitfire" as soon as 1939 was already 2000 hp+......
It didn't break the Me209's record, but it had the quickest London-Paris I belive.
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But the fact remains...the Western Allies took over the very high alt performance as soon as the Spit IX entered the game in 1942, and held it for the next couple of years, beyond the line when it was clear that the Axis would loose.
Angus:
http://www.gonzoville.com/ahcharts/index.php?p1=spit9&p2=109g2&p3=109g6&p4=190a5
http://www.gonzoville.com/ahcharts/index.php?p1=spit16&p2=p51d&p3=109g14&p4=190d9
http://www.gonzoville.com/ahcharts/index.php?p1=spit16&p2=p51d&p3=109k4&p4=ta152h
(for comparison, spit16 speed curve is almost identical to p-51D up until about 26k, falls off a couple thousand higher than the pony does)
It's not as if they're behind the 8-ball, as your post implies. They were fairly competitive up until the end. Their major weakness being (just looking at charts) their power dropped off earlier than the allied planes, which usually dropped off around 25k or so. That was rectified in very-late-war models like the 152 and the K-4.
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You are quoting AH based charts. Don't have much info on high alt or?
Remember, that in RL, over W-Europe, the fights were mostly very high up. Already in 1942, the Spit IX could cruise in formation well over the ceiling of a 109. And the turn and acceleration charts apply to 500 ft. The Spit IX and the rest with double-turbo would start kicking in at some 20K!
Give me a turn radius chart between 109G and Spit IX at 40K :devil
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You are quoting AH based charts. Don't have much info on high alt or?
Remember, that in RL, over W-Europe, the fights were mostly very high up. Already in 1942, the Spit IX could cruise in formation well over the ceiling of a 109. And the turn and acceleration charts apply to 500 ft. The Spit IX and the rest with double-turbo would start kicking in at some 20K!
Give me a turn radius chart between 109G and Spit IX at 40K :devil
To which Spit Ix are you referring to, the standard IX or the higher alt versions? Were they in service in 1942 ?
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The "standard" was made for high altitude, they were later modded "down".
They were in the game in 1942 and could cruise in battle formation at 43K, the limit for alt being the Pilot's body not taking the "bends"
I have heard a claim of a flight at 49K, but would have to get into archives to be sure it's a IX, and that would have been in 1943 or 1944.
At 35K they were at large with lots of maneuvering possibility (which goes down to nothing at ceiling), at 20K they were basically beginning to shine, since at that alt the second turbine kicked in.
Funny to have a plane modded for better performance at lower alt.....
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The "standard" was made for high altitude, they were later modded "down".
They were in the game in 1942 and could cruise in battle formation at 43K, the limit for alt being the Pilot's body not taking the "bends"
I have heard a claim of a flight at 49K, but would have to get into archives to be sure it's a IX, and that would have been in 1943 or 1944.
Are you dreaming? They had to strip Mk. IX off armor, some armament and other stuff to be able to intercept high alt german Ju86 recons at about 45k alt in September 1942 and I really doubt the standard Mk.IX was capable of cruising at 43k alt.
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Agreed. The ceiling for most of these planes was aroudn 39,000 or so, some 40,000 tops.
Also, the supercharger peaked at 25k or so. I don't see how you can take that to mean it didn't drop off rapidly above this point, and that it was still producing gobs of power up almost 20k above its peak power alt.
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Are you dreaming? They had to strip Mk. IX off armor, some armament and other stuff to be able to intercept high alt german Ju86 recons at about 45k alt in September 1942 and I really doubt the standard Mk.IX was capable of cruising at 43k alt.
Those stripped Spitfires used for intercepting the Ju 86Ps in mediterranean were mark Vs. These sripped planes had the single stage, single speed Merlin 46s while the early Spitfire IXs had the two stage, two speed Merlin 61s.
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Those stripped Spitfires used for intercepting the Ju 86Ps in mediterranean were mark Vs. These sripped planes had the single stage, single speed Merlin 46s while the early Spitfire IXs had the two stage, two speed Merlin 61s.
Still not enough for a standard Mk.IX to catch Ju 86R over England neither enough to "cruise" at 43k.
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Still not enough for a standard Mk.IX to catch Ju 86R over England neither enough to "cruise" at 43k.
are you going to back yourself up or do we have to consider your post as more anti-spit BS?
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Well if I came out and said "P51s regularly cruised at 53k" you wouldn't need to prove it wrong, you'd put the impetus on ME to prove it RIGHT.
Rather than ask for proof it's wrong I think the focus is on the person that made the 43k cruising claim in the first place.
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Still not enough for a standard Mk.IX to catch Ju 86R over England neither enough to "cruise" at 43k.
But striped IXs did intercept 86s over GB.
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But striped IXs did intercept 86s over GB.
I think by "standard" he meant un-stripped, as in a rebuttle to the claim that spit9s were super high alt monsters (the original claim)
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Well if I came out and said "P51s regularly cruised at 53k" you wouldn't need to prove it wrong, you'd put the impetus on ME to prove it RIGHT.
Rather than ask for proof it's wrong I think the focus is on the person that made the 43k cruising claim in the first place.
I'm with Krusty on this one.
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Still not enough for a standard Mk.IX to catch Ju 86R over England neither enough to "cruise" at 43k.
Do you have a power curve for the Mk. IX to back this statement up? Angus was mentioning things written and considered history. While certainly examining sources is important to consider the history credible, perhaps there's a resource out there on the internet that could back up your statement?
Or perhaps he could present his as well. I think Spitfire Performance may have what we're looking for here.
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Power curve is not the only thing that dictates how high the plane can fly it is also the aerodynamic qualities, i.e. in this case wing loading.
With the same power Spit and 109 the Spit would fly higher due to bigger wing. More thrust would mean more speed, more alt and more maneuvering options, not just flying straight.
I have been under impression that even Spit 1 could fly at 40k. However, the climb rate plots on Spit Perf pages seem to suggest that the climb rate of Mk1 falls to zero at 34-35k.
http://www.spitfireperformance.com/spit1vrs109e.html
(So to what number does the IX's climb rate point to?)
Wikipedia:
"On 5 February 1952, a Spitfire 19 of No. 81 Squadron RAF based in Hong Kong reached probably the highest altitude ever achieved by a Spitfire. The pilot, Flight Lieutenant Ted Powles, was on a routine flight to survey outside air temperature and report on other meteorological conditions at various altitudes in preparation for a proposed new air service through the area. He climbed to 50,000 feet (15,240 m) indicated altitude, with a true altitude of 51,550 feet (15,712 m). The cabin pressure fell below a safe level, and in trying to reduce altitude, he entered an uncontrollable dive which shook the aircraft violently. He eventually regained control somewhere below 3,000 feet (900 m) and landed safely with no discernible damage to his aircraft. Evaluation of the recorded flight data suggested that, in the dive, he achieved a speed of 690 mph (1,110 km/h, Mach 0.94), which would have been the highest speed ever reached by a propeller-driven aircraft."
So, going up there was a serious business and I presume "service ceiling" meaning the maximum safe altitude (and practical), not necessarily the maximum attainable altitude.
Also the power at alt is mandatory for safe flight at such heights so stripping the aircraft of any needless weight seems sensible also from point of view of maximum climb rate. That is because if somebody enters your airspace very very high the radar system may notice it rather late, meaning that you need all the speed and climb ability to catch him before he leaves your airspace, unless you are already patrolling quite high.
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I don't buy that speed listed. Probably inaccurate, as they did dive tests on spits and the propellor sheers away from the gearbox (or something related to the gear box -- the engine is trashed) well before that mach number.
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Charge, service ceiling is usually describes as the altitude when the rate of climb falls below 100ft/min.
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Probably so, not my point exactly, the dive speed, but it was flown in 1952 with a Mk19 so I presume that either the Griffon is more resilient or the "shredder" had already some serious problems with its redu gear or maybe even syphatetic oscillation which may tear the whole a/c apart in the worst case.
One lucky and one unlucky flight does not tell the truth to either direction.
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Thx Milo for clarification on that one. So it is actually the highest "practical" altitude so that you still have room for maneuvering. Of course with zero climb rate you would have none...
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Charge, service ceiling is usually describes as the altitude when the rate of climb falls below 100ft/min.
But don't forget that for specialized missions like chasing high altitude recce planes, the performance charts get stretched in actual practice. The Japanese proved to be a menace against the B-29 in aircraft that shouldn't have had a chance to intercept them on paper.