Wich Spit IX do we have

[juzz]

Spitfire LF.Vb would be nice.  

BTW, the Spitfire F.IX performance is incorrect in AH.

Speed at +16lbs matches the real F.IX(Merlin 61) at +15lbs. That's OK.

Speed at +18lbs in uncomparable to the real one, because I have never seen anything regarding the Merlin 61 and +18lbs boost!

For comparison, in AH the F.IX +18lbs speed is 10-15mph slower than the real HF.IX(Merlin 70, +18lbs) below 19k, and equal to it between 21k and 27k.

Climbrate at +18lbs matches the real F.IX at +15lbs.  

Suggestion: Remove the extra +18lbs speed, German 300l droptank, rockets and "E wing" options from the Spitfire F.IX, and add one(or more   ) of Spitfire LF.IX/VIII/XVI.  

And a FR.XIVe!  

[ 06-28-2001: Message edited by: juzz ]

[Nashwan]

Juzz, forget the 18lb boost gauge, the AH Spit performs almost exactly like the standard F IX on 15lb boost.
Climb figures are almost identical, I tested and posted the results once, but can't get the search function to work now.

xHamMerx has done some speed tests;
Alt AH F IX
1k 321  320 (Ihave seen 320 quoted at s/l)
5k 340  338 (at 6k)
10k 361 356.5
15k 380 380
20k 380 380
25k 401 391.5
30k 399 402
As you can see the figures are pretty good matches, apart from at 25k.

[juzz]

I would say the gauge is wrong, but consider this...

1. At +16lbs the AH Spitfire F.IX almost perfectly matches the (+15lbs) speed data of AB505 at all altitudes, and is also very close to the BF274 data.

2. At +18lbs the AH Spitfire F.IX is faster than both planes at most altitudes by about 5mph. Regarding the speed data listed above:

A. Generate a graph and extrapolate the s/l speed - BF274 does NOT do 320mph at s/l.
B. BF274 does (at best) 334mph at 5k.

So it is obvious that the Spitfire F.IX in AH is supposed to represent +18lbs for level speed, but this extra performance is NOT represented in the climbrate where +18lbs in AH matches BF274 at +15lbs.

Can ya dig it?  

[GRUNHERZ]

Plus we also have the AH exclusive never before modeled Spitfire Mk-P47D11!  

I love that damn plane, its a freaking spit.  

[Nashwan]

Well, if you look at the performance of an LF and HF Spit, both on 18lb boost, you see a different picture.
The LF was tuned for low down performance, the HF for high, so a standard F running 18kb boost would come somewhere between the 2, or at least close.

Alt AH  LF  HF  F
1k 321 336 329
5k 340 358 350 338
10k 361 380 371 356
15k 380 383 393 380
20k 380 398 392 380
25k 401 405 405 391.5
30k 399 395 412 402.5

The Ah fits the 15lb boost F IX quite well. At 5K it is 2 mph too fast, but about 12mph too slow to be running 18lb boost. At 10K it is 5mph too fast for a F IX, but 15mph too slow to be 18lb boost. At 15 and 20K it is exactly right for a 15lb F IX, at 25K it is close to 18lb boost, at 30k it is too slow for even a 15lb F IX.
In shhort, below 20K it is 0-5mph faster than an F IX, 3-20mph slower than an LF (15-20 at most alts), and 8-13mph slower than an HF.
As a side note, because the AH Spit doesn't have a mirror, and the tested planes did, the AH Spit is actually a bit slow at most alts, even compared to a standard F IX.

[hblair]

I followed the link that funked up posted here. I read it, and it took me back to memories of warbirds in '98 and '99. The spit IX in warbirds had it all over the 109's at that time. Onlt a 109K stood a chance against it, and it was a VERY popular plane. If you flew the spit much in warbirds, you were known as a "spit dweeb".
Well, ever since I've been flying Aces High (since the get-go) the spitfire guys have really had a sub-par spit compared to the rest of the planeset. The spit IX here is just too slow to give us luftweiners a run for their money, unless of course, you're like me and turn fight spitfires in your 109G10. I don't do it because I'm suckered into it, but because its just waaay fun when you can get angles on a better turner.

Anyways, what I'm trying to say here is I think the tea sippers have been punished enough for their dweebiness over in WB's. Throw these boys better spitfire pyro. And please make it a spitXIV. I yearn to see channel 1 lit up with "spitdweeb" like back in the glory days of warbirds.

 

[juzz]

Nashwan!

The AH Spitfire F.IX speeds at +16lbs are within 1% of the AB505 data at all altitudes. Ie; if you plotted them both on a graph like the ones on the help page, you would only see one line...

BF274 at +15lbs is identical to AH +16lbs below 15.4k, above that it is slightly different, but by far closer to AH +16lbs than the AH +18lbs speeds.
 
So it is quite clear that the AH Spitfire F.IX speed at +16lbs is intended to match the real Spitfire F.IX at +15lbs.

PS: If you want to nitpick - the AH Spitfire has the later tropical filter(like a VIII), which would negate the speed gained from the missing mirror anyway.  

[Nashwan]

No, BF274 is not identical at 15lbs to the AH Spit at 16lbs
Here is the table again, with AH Spit at 16lb 9ie without WEP). All AH speed tests by xHamMerx
Alt AH , LF, ,HF, ,F, ,AH 16lb
1k 321 . 336 329. . . . .318
5k 340 . 358 350 338 . . 333
10k 361, 380 371 356 . . 355
15k 380, 383 393 380 . . 375
20k 380, 398 392 380 . . 378
25k 401, 405 405 391.5 . 395
30k 399, 395 412 402.5 . 399

At 16lbs the AH Spit is slower than the 15lb real Spit at all altitudes up to 25k, where the AH model seems to have some real problems.
At 5k the AH Spit at 18lb is closer to reality. At 10K 16lb is closer to reality, at 15k 18lb matches exactly, 16lb is too slow, at 20k the same is true.
Add up the difference between 5k and 20k and average them. At 18lb the AH Spit is on average just under 2mph too fast, at 16lb is is just over 3mph too slow.
As you say, climb rate also matches at 18lb, and is well off at 16lb.

[Nashwan]

Juzz, are you sure it has a tropical filter? It certainly doesn't look like it to me, and would be a bizzare choice, as very few IXs had the tropical filter. Still, it would fit with the way HTC chooses to model Spits, as the worst variants. I am suprised we didn't get the IX with floats instead  
It's not actually a nitpick about the mirrors. Mirrors were fitted to give a view to the rear, their drag was accepted in light of the improved view.
AH doesn't model the mirror, doesn't model the rear view, so why should it model the drag?

[Pongo]

The tropical filter on a Spit IX or Spit VIII was much harder to spot then the volks filter on a spit V. I dont think I had any effect on the performance of the AC. I may be wrong I dont have my reference here.

[juzz]

At 16lbs the AH Spit is slower than the 15lb real Spit at all altitudes up to 25k, where the AH model seems to have some real problems.

The data given for AH +16lbs is actually faster than AB505 below 12k. It is also faster than BF274 would be below 4k.

At 5k the AH Spit at 18lb is closer to reality.

Nope. You forget that 338mph is for 6k - at 5k the BF274 figure is more like 333.5mph(AB505, 330mph). So I think, 333mph is closer.

At 10K 16lb is closer to reality, at 15k 18lb matches exactly, 16lb is too slow, at 20k the same is true.

At 20k; AH +16lbs matches AB505 data, while AH +18lbs matches BF274 data.

At 25k, AH +16lbs matches the AB505 data exactly. BF274 was about 4mph slower than AB505 above 22k, for some reason.

Add up the difference between 5k and 20k and average them. At 18lb the AH Spit is on average just under 2mph too fast, at 16lb is is just over 3mph too slow.

It's easy to see if you plot a graph. Then it is clear that AH +16lbs ~= RL™ +15lbs.

[funkedup]

Juzz, refresh my memory.  What happens if you plot the BF274 speeds without the error corrections?  Don't they match the AH data better?

(By AH data I mean Pyro's charts)

[ 06-29-2001: Message edited by: funkedup ]

[juzz]

Huh? I'm only using the TAS data - error corrections are for IAS, right?

[Zigrat]

no guages are known to be inacccurate, they figure out the inaccuracies and make a correction chart. not the same thing.

[funkedup]

I think in the BF274 tables they took the ASI readings and added the PEC (position error correction) and Comp. (compressibility correction) values to get an adjusted ASI which was then adjusted for density to give TAS.

If you skip the PEC and Comp. adjustments and go straight to the density adjustment, you get 421 mph at 27400 feet.  I'm not sure if that means anything, too sleepy right now.  

(I'm talking about chart for level speeds, combat rating, no fuel tank in this document: http://www.fourthfightergroup.com/eagles/bf274.html  )

[ 06-30-2001: Message edited by: funkedup ]