109G vs spit9, 109g vs p51

[Ardy123]

In general I respect and like what Badboy achieved in his broad models.  

Having said this I disagree with the flight mechanics of the model wrt low ratios of Vturn/Vmax at or near CLmax.  

Simply, absent CFD and/or flight test data for variations in Parasite drag due to increases in AoA - which is required to achieve the low speed T=D equations -

you just can't 'get there from here' with level flight, low AoA models based on level flight CLmax at Power on stalls or CDo for sub mach critical speeds calculated from max level flight dash speeds with known HP and known altitudes and Gross Weights.

As to 'fixing it', I have no suggestions which embrace everything from a 'draggy Me 109G' to a 'clean P-51D' in high bank angle, asymmetric, high AoA, large viscous drag flight conditions in which even Prop efficiencies at max power/low airspeed are suspect.

Which, Ardy, caused me to ask about your sources for the results..

Thats a good point, I wonder if and how AH models parasite drag? But at low speeds, wouldn't it be more induced drag and not parasite drag?

[Widewing]

The thing is, is that Skip Holms is correct.

In the video, the 109 looks like a g2

A G2 will turn with a spit (within 20 feet). All the 109s will out turn a p51 any day.

No, he's not correct. He stated that the 109G would out turn a Spit IX in answer to that question (he said, "sure"). It will not. He didn't specify which G model, but it really makes no difference. Also, Gonzo's Spit IX turn radius is suspect when compared to the Spit XVI, which is a Spit IX with a low altitude engine. I can match the Spit XVI's turn radius with a Spit IX (571 feet, no flaps). I can't match the rate (at low altitude) being down on relative power. My preferred Spitfire is the Mk.VIII, which has better low speed handling than the Mk.XVI, and superior acceleration and climb relative to the Mk.IX Spit.

That said, lets look at the the test methodology used to get the in-game turn data. All data is taken close to sea level. The Spitfire IX in the game has an engine optimized for high altitude. Do that test at 25k+ and the Spit IX will embarrass any 109G. That's an important context. On the other hand, if sea level data is valued, compare the Spit XVI to the 109G-2 and things get really dicey for the 109 very quickly.

Don't misunderstand me... When I was a Trainer and flying on a regular basis, I could hold my own with anyone in a 109 dueling 109s or dissimilar types. I like the 109s...

[Ardy123]

No, he's not correct. He stated that the 109G would out turn a Spit IX in answer to that question (he said, "sure"). It will not. He didn't specify which G model, but it really makes no difference. Also, Gonzo's Spit IX turn radius is suspect when compared to the Spit XVI, which is a Spit IX with a low altitude engine. I can match the Spit XVI's turn radius with a Spit IX (571 feet, no flaps). I can't match the rate (at low altitude) being down on relative power. My preferred Spitfire is the Mk.VIII, which has better low speed handling than the Mk.XVI, and superior acceleration and climb relative to the Mk.IX Spit.

That said, lets look at the the test methodology used to get the in-game turn data. All data is taken close to sea level. The Spitfire IX in the game has an engine optimized for high altitude. Do that test at 25k+ and the Spit IX will embarrass any 109G. That's an important context. On the other hand, if sea level data is valued, compare the Spit XVI to the 109G-2 and things get really dicey for the 109 very quickly.

Don't misunderstand me... When I was a Trainer and flying on a regular basis, I could hold my own with anyone in a 109 dueling 109s or dissimilar types. I like the 109s...

I don't understand, your saying that on the deck, the spit 16 (spit XVI) will out turn a 109 G2? Thats not inline with the your & Gonzos tests (your given credit for some of the figures according to gonzo). With no flaps the spit 16 will by 60 feet, but with flaps, the difference is 17 feet!

---spec---	---P51 D---	---P51 B---	---Spit 16---	---Spit 9---	---109 G2---	---109 k4---
turn (no flaps)	777	766	567	632	636	703
turn (full flaps)	633	598	450	433	467	533

[Stoney]

"Out turn" = sustained turn radius. The figures I posted were for best sustained turn radius.

I was talking about your last point where you said "in a G2, I can 'turn' with Spits all day"...

You missed my point.

[Ardy123]

I was talking about your last point where you said "in a G2, I can 'turn' with Spits all day"...

You missed my point.

Ahh...
That comment was in reference to the fact that many spit pilots go into endless flat turns on the deck when they are in trouble in AH. I can follow them in their turns in a G2, I can't in a k4 (I have to do yo-yos or some other acm to cut it).

[Widewing]

Ahh...
That comment was in reference to the fact that many spit pilots go into endless flat turns on the deck when they are in trouble in AH. I can follow them in their turns in a G2, I can't in a k4 (I have to do yo-yos or some other acm to cut it).

My point is simple... The 109G2 won't live long enough to get slowed down enough to deploy flaps. The Spit XVI accelerates faster, climbs as well or faster, rolls much faster and can turn a smaller circle at a higher turn rate.

Another point to remember is that the majority of air combat on the western front was flown at much higher altitude than you will typically see in Aces High.

[Ardy123]

My point is simple... The 109G2 won't live long enough to get slowed down enough to deploy flaps. The Spit XVI accelerates faster, climbs as well or faster, rolls much faster and can turn a smaller circle at a higher turn rate.

Another point to remember is that the majority of air combat on the western front was flown at much higher altitude than you will typically see in Aces High.

Ok fine, I'll bite...

The above post is total BS...  And with all the times you have told others to not make "blanket statements" to say something like that makes you appear like a complete hypocrite.
There are so many factors that go into that equation and you once being a trainer,  you know that.

Regardless... The topic was on turn radius not fight, and at full flaps its 17 feet difference (roughly) on the deck.

[moot]

Take it easy Ardy.. 

The XVI does trump pretty much anything the G2 can come up with against it..

[Ardy123]

Take it easy Ardy..  

The XVI does trump pretty much anything the G2 can come up with against it..

I think he was trying to start a BBS fight as the original topic was about turn radius.

[Widewing]

Ok fine, I'll bite...

The above post is total BS...  And with all the times you have told others to not make "blanket statements" to say something like that makes you appear like a complete hypocrite.
There are so many factors that go into that equation and you once being a trainer,  you know that.

Regardless... The topic was on turn radius not fight, and at full flaps its 17 feet difference (roughly) on the deck.

So, you're saying that what I said isn't true?

And, yes, we're discussing a very specific dynamic... Turn radius. Just understand that you cannot isolate turn radius from turn rate. Turn rate, IMHO, is the more important factor.

In a duel there are just two variables to the equation... Pilot skill and aircraft. Spit XVI vs 109G2, call pilot skill equal. 109G-2 dies. That's not a blanket statement, it's a very specific fact.

[Ardy123]

So, you're saying that what I said isn't true?

And, yes, we're discussing a very specific dynamic... Turn radius.

I'm sorry, I thought you were trying to pick a BBS fight as you changed it to being about a fight from turn radius. My apologies if you were not. No, I agree with you that barring equal pilots, a spit 16 will win in a duel, but in terms of turn radius, I believe the spit 16 and the g2, with full flaps are very close.

[Guppy35]

LOL, if the guys in the video are your argument for a better turning 109, I'd skip it.  The "109" that Skip Holm has flown is a Spanish built Buchon not a 109G.  Good luck on finding a 109G to fly.  The last one in the air was the IWM 109G2 that crashed and is now static at the RAF Museum.  Those in Germany are rebuilt Buchon's with DB engines.

Skip Holm's 109 flying is behind a Merlin engine

[B3YT]

well that guy just needed to read AAR from german pilots to see that the spitfire would out turn the 109.    German pilot training told them not to turn with spits but to use slashing attacks and keep speed. Next that guy will say the hurricane would only just take off.

[drgondog]

Thats a good point, I wonder if and how AH models parasite drag? But at low speeds, wouldn't it be more induced drag and not parasite drag?

I suspect that the only parasite drag modelled in AH is zero lift parasite drag.  Drag has four components, one of which is irrelevant for sustained turns - namely compressibility.  The other three however are Parasite drag, Induced drag and viscous drag due to lift and changes to AoA.

For velocities below max L/D on the drag polar, drag is dominated by Induced Drag. At CDmin for level flight L/D is max and CDi = CDo for level flight. For level flight conditions from stall to near max speeds (below the start of compressibility ( at ~ .55-60M) you can perform all your performance derivatives with T=D, Drag = Induced and Zero Lift Parasite Drag

Virtually all the sustained turns for WWII fighters were at or below CDmin values for level flight...  This is where the modelling gets tricky because holding altitude in a sustained turn REQUIRES significant elevator and rudder deflection - adding trim drag - and the dramatically increased AoA to push the a/c to the max sustained turn rate increases viscous drag - another delta to parasite drag. Induced drag should still be the most important until the a/c approaches stall range velocities but this is where the combination of viscous and zero lift parasite drag combined is nearly equal in magnitude to induced drag.

[Vinkman]

I am also curious as to the state of the guns, armor, self sealing tanks and ammunition on that Bf109G.

This.