Aces High Bulletin Board
General Forums => Aircraft and Vehicles => Topic started by: Fishu on December 14, 1999, 12:02:00 AM
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I am really glad what you did for 109, now it feels like real one, instead of being brand W's G6..
..but (hey now, dont look at me like that!), I have achieved speeds like 415mph at 11,400ft with WEP on, at 14,500ft almost same speed without WEP and at 16,500ft as fast as 440mph with WEP (wonder if it goes 500mph at 25,000ft.. hehe, that would be something)
Just wonder are these realistic speeds for 109 or is that speed gauge just having some errors? (http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif)
Didn't expect any plane to be that fast, when even P-51D does about 437mph at 25,000ft and thats faster than 109G10 should do, right? (and im breaking it at 16.5k)
....but (yes, you can now look at me like that) I'd be happy if these are the real numbers (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif) (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
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So, are you trying to say that there is a Luftwaffe conspiracy, trying to spoil online sims ? (http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif)
Also, we both know that 109 speed gauge has errors, just remember IAS/TAS differences at low alt.
[This message has been edited by Hristo (edited 12-14-1999).]
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Fishu - I'd be more worried about the FW190A-8. It's the slowest climbing fighter in AH and it's top end at high alt sucks too(only the N1K2-J is slower) - how did you get 271 kills for 0 deaths in it? Imagine if you flew the Mustang! (http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif)
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Fishu, these numbers are just off the top of my head, but I seem to remember seeing performance numbers for the K4 as high as the 440-450 number, depending on the source.
Plus remember that the G10 has a much more powerful engine than the G2/G6, so its more comparable (equal in my opinon) to the Brand W, 109K4.
I haven't been in the game since last week, but if the 109 finally has that kind of power again, you might just convince me to fly it (http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif)
Even with that crappy gun package (http://bbs.hitechcreations.com/smf/Smileys/default/biggrin.gif)
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Vermillion
WB's: (verm--), **MOL**, Men of Leisure,
"Real men fly Radials, Nancy Boys fly Spitfires ;) "
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The 109 is very nice now. Still a hand full in a dive, still have to watch that ammo, but
man can it accelerate, great high speed manuverability. Some people where complaining that the spit is a wipping dog now compared to the the 109. I dont think that that is true but you have to respect the power of the 109 now. Ponys should be carful. You show this bird your backside with less then 3-4k of head start and you could be in big trouble. I want to see how it goes up in Buff land....Will is still have good power at 28-34k?
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Juzz: that plane fits for me (http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif)
About 190a8, what worries me, is that I have read it flown +400mph as top speed, not 390mph which I get as top speed on level flight.
(I wonder if that number 13 on the side of 190 gives me a kick, its my lucky number)
Vermillion: G-14 and K-4 are more comparable, I think that G-10 is still some mph slower than K-4
Btw. You sure the speeds you've heard haven't been achieved at 25,000ft, which is totally different altitude than 16,000ft?
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G-14 and K have different engine,
G-10 and K have same engine..
Why would G-14 and K be more comparable?
G-14 and late G-6 are comparable.
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109K had retraceable tailwheel (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
Also, I believe it had small landing gear doors, similar to P 51D in AH.
Speaking of tailwheel, shouldn't our 109G-10 have long tailwheel ? Looks cool, and would also help in take offs, IMO.
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I believe Pongo is right Fishu, its the G10 and the K4 that have the same engine. Forget what was in the G14, beyond the designation AS. But I don't remember what the AS signifies.
On the altitude of 16k vs 25k, I admittedly have no clue. Like I said, I just remember that in some references (again speaking from memory) that the K4 had top speeds in the 440-450 mph TAS range.
So it may indeed be too fast, best way would be to check the speed at the altitude which most references state where max speed occurs, then use that as the speed in the post to compare too.
Again, speaking on all issues from memory here (am at work), so I may be in error.
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Vermillion
WB's: (verm--), **MOL**, Men of Leisure,
"Real men fly Radials, Nancy Boys fly Spitfires ;) "
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I think speed is ok for the 109. The Problem is: the 109 get itīs maximum speed not in the right altitude.
At the moment the 109 has itīs max speed in 20000ft, about 6500m. But the 605D engine (which has also like the 605AS a bigger loader compared to the 605A) had a "full-pressure-altitude" of 8500meter, 28000ft. Thatīs why a G10 and K were faster than other 109Gīs- The engine was able to perform full power in bigger altitudes than the other engines. They didnīt had more HP. Without MW50 i found even original data that says a 605D and a 605AS had for takeoff 1435HP, a 605A 1475HP.
The 605AS was good, too. But the "air loader" (sorry, donīt know the correct technical expression in english:-) ) of the AS had itīs limit in about 7400m, 24400ft.
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air loader = supercharger I would imagine.
I have seen these figures.
Bf109G-6, DB605??(GM1 boost) = 406mph at 28500ft
Bf109G-10, DB605DC = 426mph at 24000ft.
Bf109K-4, DB605ASCM = 452mph at 19685ft, 435mph at 24610ft.
Bf109K-14, DB605L = 452mph at 37000ft.
DB605ASOM engine, 2030hp using 93-octane fuel and MW50 boost. Fitted to some Bf109G-6
The K-4 had aerodynamic improvements that the G-10 didn't. Inner gear doors, more streamlined cowling over the upper machineguns, etc. However, the K series was supposed to be a "standardisation" of all the R- and U- modifications being applied to the G-10. So a late production G-10 is probably the same as an early K-4.
It's my understanding that MW50 only gives power improvement up to 22000ft. Is this correct? I have no idea which altitude range GM1 is for, except that it's obviously best to use it at higher altitudes. It would certainly give more power at any altitude. (After all it works great on your car at 0ft (http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif))
[This message has been edited by juzz (edited 12-14-1999).]
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Gotta disagree with you Niklas. Can you point me at the info you're referring to?
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Doug "Pyro" Balmos
HiTech Creations
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The increased supercharger on the 605D and AS engines raised the critical altitude from something like 5700m (605A) to 8000m. With full boost (MW50), the critical altitude is much lower, 5100m for c3 fuel (1800hp) and 6000m for b4 fuel (1530 hp).
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Gotta question wells (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
How is/was the critical altitude defined?
Am guessing a 200HP drop from max HP?
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Pyro- I already sent you a mail with a big attachement. I will sent you some other data now, one is a propeller test with a K and a 605D engine. It shows clearly the max speed at combat power (1,35ata, 2600 u/min)- top speed at 8500m (without mw50).
I have a copy of an original table of Daimler-Benz, dated spring 44.
It says:
DB605A
Fuel B4, propeller adjustment by hand
compression 7,3/7,5
full-pressure-height: 5700m
takeoff and emergency power:
ground: 1475HP @2800u/min, 1,42ata(pressure)
fph: 1355HP (5700m!)
10000m: 790HP
15000m: 320HP
DB605AS
Like 605A, bigger supercharger of the 603G
compression 7,3/7,5
full-pressure-height(fph): 7500m
takeoff and emergency power:
ground: 1435HP @2800u/min 1,42ata
fph: 1225HP (7500m!)
10000m: 890HP
15000m: no data
DB605D
Like 605A, bigger supercharger, propeller adjustment works automatic, fuel C3
compression 8,3/8,5
full-pressure-height(fph): 8500m
takeoff and emergency power:
ground: 1435HP @2800u/min 1,42ata
fph: 1210HP (8500m!)
10000m: 1000HP
15000m: 410HP
All data without mw50 or gm1
wells posting imo the clue to the solution, i think. I know thatin many books who find for top speed of a 109K an altitude of about 6000m, with much higher number of HP- Wells is right i think, there they used mw50, and therefore the critical altitude dropped- i dontīt know why but it seems to be a fact.
I have another data for the 605D, now with mw50:
takoff and emergency power:
ground: 2000HP @2800 u/min 1,98ata
5500m: 1800HP @2800 u/min 1,98ata
climb and combat power:
ground: 1800HP @ 2800 u/min 1,8ata
6000m : 1530HP @ 2800 u/min 1,8ata
It really looks like that with mw50 the critical altitude dropped.
BUT without mw50 (and i did my speed tests like wells did them without wep, and my climb tests too) the critical altitude should be much higher than it is now.
niklas
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Thanks Niklas, I haven't really reviewed them yet, but I think I've seen them before. I'm now getting into the detailed modeling and will take a good look at it when I get to the 109. Anything further you want to send would be greatly appreciated. (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
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Doug "Pyro" Balmos
HiTech Creations
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chisel,
Critical altitude is defined by the ability to maintain manifold pressure. The lower the required manifold pressure, the higher the critical altitude. For the high boost pressures (1.98 ata), the altitude is lower. From the engine data that I have, the boost would start falling at 5100m (1.98 ata) until 8000m where the maximum boost pressure would be 1.42. Using MW50 at that height would have little effect as no higher boost pressure could be obtained, however according to Janes, MW50 could provide a 4% increase in power for a constant boost pressure. At 8000m, where the engine puts out 1200 hp or so, MW50 would only add about 50 hp, compared to some 300 or so at sea level.
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Hmmm. More 109 discussion.
Ok. Here. Go read this.
http://users.aol.com/dheitm8612/breed.htm (http://users.aol.com/dheitm8612/breed.htm)
Talk amongst yourselves <hand stir>
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ok wells, i think i understand it now:-)
mw50 doesnīt GIVE an engine more boost, it only ALLOWS more boost- Because due to the cooling effect it reduces the thermical stress of the engine components, right?
niklas
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Westy, interesting reading, but was DB601 really a direct injected engine, where fuel is injected directly to cylinder instead of intake manifold (near the intake valve), or is there an error ??
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I believe Direct is correct. A manifold would allow G forces to have too much effect on fuel. And historically we know the 109 never had any problems with this matter as opposed to RR Merlin engines.
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If your in range, so is the enemy.
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Wells,
So basically what difference does the crit alt make to us?
The max HP drops with the altitude change anyway ,even with the same MAP (I assume from energy lost to drive the blower/temp change with alt?). The only thing you can really compare engines with is the max brake HP at altitude.
Were all these ratings done with the 109 ram intake taken into account? Dont know there affect at altitude but they work at sea level if your going fast enough, 160mph+
Janneh
im 99.9% sure they were direct injection with the injector mounted between the valves spraying into the combustion chamber.
[This message has been edited by chisel (edited 12-17-1999).]
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Jeez! another question! Hope somebody answers (http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif)
If the Ram scoop does make a difference how much loss would there have been on plane fitted with a trop. filter?
Time for bed G'nite.
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Janneh, I do not know. Chisel, I believe the report dealt with the plane as it related to combat.
The 109 was not a feared aircraft from any story I've read. Unless the pilot had failed to check his 6 and allowed one to get back there or if it was coming down in a dive on him. The 190 was a different story.
Mustang pilots had no compunction from getting in the weeds with 109's or 190's
People can whip out thier notebooks and rattle off specs left and right but it doesn't change how things WERE. Not what they hypothetically should have been.
-Westy
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Westy: is this now from the point of living or fightning? (http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif)
Also could consider that was this generally considered thing... (note: I don't think every LW pilot were like Hartmann, whom must been more feared in 109 than 500 other pilots)
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Chisel you are correct - as you increase the altitude, the blower has to do more work to keep a constant M.P.
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Sounds wery odd to me. If german engineers found out direct injection on gasoline engines on WWII, why the heck it wasn't an option, say, 1960 in cars ? I mean it is now, 1999 , but why so late ? After all turbos(HORRAY SCANDINAVIA (http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif), direct ignition's and others...
I still don't believe it was direct injection, atleast, on those octanes.
Perhaps,Chisel, my friend, can help me with this (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif) Yeah, I'm a suspicious, until, someone clears me.
If You inject gasoline in intake manifold enough in vaporized mode, it'll doesn't make any difference, if You're in negative or positive maneuver, that's for sure.Vapor is so much lighter than liquid gas, gravity doesn't effect so much...DOH am I totally lost here, or can someone show some proof here, just for interest ?
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janneh, when was the last time you pushed any negative g's in your car? (http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif)
Direct fuel injection into the cylinders of the engine is provided by means of a twelve-unit high-pressure pump mounted between the cylinder blocks where it is fed by a Graitzin transfer pump.
quote from http://members.aol.com/bf109gust/webhtmls/engine.html (http://members.aol.com/bf109gust/webhtmls/engine.html)
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Janneh think about it for a second, Direct injection is a very crude work around to get away from Negative G effects in 1939, Unlike your modern types it worked off a very (By todays standards) primitive fuel injection system. Those motors needed regular service to clean them and were always running very rich (I believe the richness had to be controlled by the pilot as well). no-one in their right mind would put one on an assembly line production car.
As for negative G's and fuel vapour, your comment makes no sense. G's affect the mixture of vapour. In your car you will never notice this but under any condition where you are pumping force onto a manifold you will have problems. I could not even try to go into all the affected things but Drag cars, aeroplanes and high performance boats all have systems to minimize the affect G has on them. As you introduce rapid changes the effects are: vapour becomes unevenly distributed, more fuel concentration to one side of the manifold less on the other causing lean burning. Vapour actually is forced back along the line of the force applied. Vapour is affected by the force of G, push on it and it moves. Thus in manifolds the side closest to the force applied runs lean and is starved for fuel.
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The Bf109 series only had manual controls for throttle and propellor pitch(not rpm as in British/American planes). Sorrow, why would a direct-injection engine always run rich? I would think such a situation would be unacceptable in a fighter aircraft engine.
Seems the DB600-series engines, were great engines unfortunately fitted to an average Bf109 airframe. (http://bbs.hitechcreations.com/smf/Smileys/default/redface.gif)
[This message has been edited by juzz (edited 12-18-1999).]
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Because, with a mechanical fuel injector, not using a computer to measure air pressure, etc etc all engines run slightly rich (being a whole lot safer than lean!) Technology only went so far back then. I am not so sure about those being the only to controls.. I am POSITIVE there was a mixture control somewhere on that plane. Otherwise there would be no adjustments at all for high altitude flying.
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If your in range, so is the enemy.
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Actually after a bit of research it appears there WASN'T one... how odd. I am curious now how they did it. Somehow on the supercharger they had some way of adjusting boost to compensate for lower oxygen levels at alt? or did they actually figure a way to measure fuel mixture in the injection pump back in '39?
How odd. 2 other things that came to mind are that yes, all fighters ran rich in combat. It compensated for the massive drops and rises in air pressure at alt in combat. Wasn't a big deal, those motors got overhauled regularly anyway.
The other was the memory that with direct injection you pretty much HAVE to have a constant air pressure. hence with cars who was going to bother adding it when you had to have a super or turbo charger? It probably wasn't a serious idea until nowadays that we see turbo's and supers on 4cylinder cars becoming more common.
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If your in range, so is the enemy.
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Sorrow,
They invented a small, thin, flat piece of rubber called a diaphram (http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif)
So what if they ran a little rich? ALL of them did, carburated or injected. Helps keep it cool and prevents detonation.
Daimler used a hydraulic slip clutch on the blower drive controlled by atmosheric pressure. pressure drops, clutch tightens up and blower spins faster.
Just a guess but I think the big thing with neg G on carbs is the float needle popping open or staying shut. flooding or starving the engine.
Juzz,
When I first saw "Direct" injection on these engines I was in disbelief. Not because it was injected but because spraying the gasoline directly into the combustion chamber still isnt done on a car to my knowlege. Could be wrong, I'm a diesel guy. (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
With regards to use on cars. Porsche used Bosche mech. fuel injection in the 60's 70's
Did the corvair have fuel injection? Was basically a continental flat six wasnt it?
I asked this question before and there were 2 cars that used pressure carbs. They are cheaper than fuel injection and infinately better than float carbs why werent they used.
Antilock brakes have been around since the 40's on planes why werent they used on cars?
Betcha it has more to do with cost than anything. Computer just made these items cheap enough and idiot proof for mass consumtion.
[This message has been edited by chisel (edited 12-19-1999).]
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The '57 Vette was fuel injected.
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I agree Chisel, cost more than anything. BTW the 289 GM motor had mechanical fuel injection, so did mid 30's buicks and several other cars. Complexity was their downfall, too hard to service.
I think the problem with carbs was to do with fuel being unable to draw properly when the negative pressure exceeded manifold vacuum. Later Packard Merlins utilised superchargers and pressurized fuel systems to overcome this. However to the best of my knowledge most spitfire IX's should still have engine failure under heavy negative G. Not as bad as mark I or mark V but it should still happen.
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If your in range, so is the enemy.
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Thanks guys for details (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
Was that old bosch fuel injection named something like "Kulgerfischer" ?
Chisel, if I recall it right, I've read somewhere about direct injection(gas) car, a japanese car and it's already in serial production.
BTW, was there any water injection used on these plane engines ?
Nice site juzz (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
Sorrow, that negative G effects on spits (all spits), should be modelled in AH.
Otherwise it's allied conspirancy (http://bbs.hitechcreations.com/smf/Smileys/default/biggrin.gif)
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Diverting a bit now...
So Spits should have problems with negative Gs, even in their later versions ? How about P 51 ?
BTW, both of these planes can readily push more negative Gs than 109. Not as drastic difference as before, but still too great. 109 should be better in that regard, both elevator and engine wise, shouldn't it ?
AH 0.42 109 has to be trimmed down to do it, and it still won't do it as fast as Spit or P 51, at any speed. There is also nose bounce effect, so in 109 it is usually -2g, 0g, -1g sequence.
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P51 has no problems Hristo, they used Packard Merlins. Packard solved all the problems of high altitude. Their intake system and carbs were very different than the ones RR was using. It was Packard's sharing of this knowledge that allowed the late Spit IX finally be totally free of any high G problems. The early and mid ones were results of RR trying to fix the problems themselves and were only partially successfull. Actually it's relative, the fixes began back with the Mark V. But with every fix they found more problems. The IX shouldn't have too many stall conditions, only under 5-7+ -G would it probably start to have issues. This is probably why it isn't even modelled in AH. We fly a late model IX, the odds of it being in a high -G situation proabably weren't worth making it stall there.
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If your in range, so is the enemy.
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So are we saying the down elevator issue on 109s is still an issue? My last two online sorties were in 109s (got bored dying in ponies and hawgs and decided to die in something else (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)), and I noticed that it seemed I just couldn't get the nose down quickly, even at sub-compression speeds.
But I'm about as far from an experten as you can get, and would be happy to hear from those who know more than I do....
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Flathat
'Black Dahlia'
No10 RNAS "The Black Flight"
Angel on your wing, devil on your tail
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Flathat, this is only my subjective remark. It would be nice to have opinion of real 109 expert, -ik-.
109 has somewhat slow trim response and it requires quite a bit of trimming during flight, especially compared to 190 (requires almost no elevator trim). This is ok, IMHO. But still, its down elevator is worse than the one in Spit or P 51D, even if trimmed nose heavy.
From what I have heard, and from WB model as well, it should be just the opposite. Hartmann's escape is now easier in Spits than in 109.
And nose bounce makes things even worse. Here's usual case at moderate speed, trimmed for level flight. You push elevator and achieve some -2g (far more achieveable in Spit or P 51). Then the down movement stops (nose bounce) and you can read 0g. After that it is some -1.5g sustained. Even if you started trimming the elevator down at the beggining of the maneuver, the results are still not all that good.
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Yep--I wasn't reading the gauges at the time but otherwise that describes my experience under conditions closely resembling what you described. Thanks, Hristo.
(Changing the subject a little) You know, the worst thing about having limited flying time is not so much that I don't become a feared experten, but that I don't get enough time in each of the available rides to determine whether or not it's for me. I suspect that my particular brand of dweebishness is ultimately going to make me a HawgDweeb(tm), but who knows? I might really learn to love the 109, La-5 or Veltro, particularly if the latter had fuel enough to do more than take off and land. I've flown them all along with the Pony (a lot) and the Spit (once). That's what stops me joining a squad, too--the thought that I Might Be Missing Something. (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
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Flathat
'Black Dahlia'
No10 RNAS "The Black Flight"
Angel on your wing, devil on your tail
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a li'll out of subject ... but HawgDeweeb?? naawww Dweebfire -> THAT's the ultimate Dweebplane (http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif) -> and yes please give them negative G limitations..