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View Full Version : The P-51 wasn't the best fighter of WW2



Takata_
06-26-2005, 08:13 PM
... designed by Kurt Tank.

But, the Gladiator J8A a much better glider, engine off, than the P-51. May someone explain me what makes a plane glide, and why the Gladiator distance is 30% better than the P-51?

GLIDE TEST - Crimean map, 12h
wind/turbulences turned off
Alt : 1000 m (mission setting)
Speed : 300 km/h (mission setting)
fuel: 0% (mission setting)
ammo: empty (mission setting)

Distance is mesured from starting point to crash point; average speed (TAS) is calculated from linear distance and flight time; propeller 0% or feathered; radiator closed; plane trimmed.
error margin =~ 1% (100m / 10 km).

1st col. = distance covered
2nd col. = glide duration (min' sec")
3rd col. = average speed (TAS)
4th col. = gliding plane

<hr class="ev_code_hr" />
-best glide

COMMONWEALTH

13.52 km --- 5' 59" --- 136 km/h --- Gladiator.J8A

10.88 km --- 3' 36" --- 181 km/h --- Hurricane.Mk.Ia
10.04 km --- 3' 06" --- 194 km/h --- Hurricane.Mk.IIb
10.38 km --- 3' 14" --- 193 km/h --- Hurricane.Mk.IIb Mod
09.94 km --- 3' 04" --- 194 km/h --- Hurricane.Mk.IIc

10.30 km --- 3' 33" --- 174 km/h --- Siptfire.Mk.Vb
10.43 km --- 3' 36" --- 174 km/h --- Siptfire.Mk.Vb.CLP
10.10 km --- 3' 21" --- 181 km/h --- Siptfire.LF.Mk.Vb
10.08 km --- 3' 24" --- 178 km/h --- Siptfire.LF.Mk.Vb.CLP
10.37 km --- 3' 33" --- 175 km/h --- Siptfire.Mk.Vc.(2)
10.34 km --- 3' 26" --- 181 km/h --- Siptfire.Mk.Vc.(4)

10.09 km --- 3' 24" --- 178 km/h --- Siptfire.Mk.VIII
09.96 km --- 3' 17" --- 182 km/h --- Siptfire.Mk.VIII.CLP

09.99 km --- 3' 18" --- 182 km/h --- Siptfire.Mk.IXc
09.97 km --- 3' 24" --- 176 km/h --- Siptfire.Mk.IXc.CLP
10.06 km --- 3' 20" --- 181 km/h --- Siptfire.Mk.IXe
09.92 km --- 3' 17" --- 181 km/h --- Siptfire.Mk.IXe.CLP
09.91 km --- 3' 24" --- 175 km/h --- Siptfire.HF.Mk.IXe

09.87 km --- 3' 21" --- 177 km/h --- Seafire.Mk.III
09.86 km --- 3' 13" --- 184 km/h --- Seafire.F.Mk.III

<hr class="ev_code_hr" />
USA-ARMY

12.95 km --- 4' 05" --- 190 km/h --- Hawk-81A-2
12.95 km --- 4' 18" --- 181 km/h --- Tomahawk.Mk.IIa
12.90 km --- 4' 14" --- 184 km/h --- Tomahawk.Mk.IIb

12.97 km --- 4' 07" --- 189 km/h --- P-40B
12.99 km --- 4' 05" --- 191 km/h --- P-40C
13.11 km --- 4' 10" --- 189 km/h --- P-40E
12.50 km --- 4' 07" --- 182 km/h --- P-40E.M-105
11.98 km --- 3' 37" --- 199 km/h --- P-40M

10.68 km --- 3' 15" --- 197 km/h --- P-400

10.62 km --- 3' 13" --- 198 km/h --- P-39D-1
10.64 km --- 3' 14" --- 197 km/h --- P-39D-2
10.69 km --- 3' 15" --- 197 km/h --- P-39N
10.85 km --- 3' 22" --- 193 km/h --- P-39Q-1
10.97 km --- 3' 25" --- 193 km/h --- P-39Q-10

11.34 km --- 3' 14" --- 210 km/h --- P-63C

16.89 km --- 4' 06" --- 247 km/h --- P-38J
16.00 km --- 3' 54" --- 246 km/h --- P-38L
16.14 km --- 3' 48" --- 255 km/h --- P-38L.Late

11.61 km --- 3' 08" --- 222 km/h --- P-47D-10
11.71 km --- 3' 17" --- 214 km/h --- P-47D-22
11.80 km --- 3' 20" --- 212 km/h --- P-47D-27

10.54 km --- 3' 00" --- 211 km/h --- P-51B
10.58 km --- 3' 03" --- 208 km/h --- P-51C
10.58 km --- 2' 55" --- 218 km/h --- Mustang.Mk.III
10.49 km --- 2' 56" --- 215 km/h --- P-51D-5NT
10.49 km --- 2' 53" --- 218 km/h --- P-51D-20NA

USA-NAVY

09.08 km --- 2' 51" --- 191 km/h --- Brewster.B-239
09.44 km --- 2' 53" --- 196 km/h --- Buffalo.Mk.I
09.78 km --- 2' 53" --- 203 km/h --- F2A-2

11.34 km --- 3' 15" --- 209 km/h --- F4F-3
11.38 km --- 3' 20" --- 205 km/h --- F4F-4
11.63 km --- 3' 18" --- 211 km/h --- FM2

12.44 km --- 3' 32" --- 209 km/h --- F6F-3
12.43 km --- 3' 29" --- 214 km/h --- F6F-5

12.70 km --- 3' 22" --- 223 km/h --- F4U-1A
12.87 km --- 3' 32" --- 219 km/h --- F4U-1C
12.79 km --- 3' 26" --- 224 km/h --- F4U-1D
12.90 km --- 3' 36" --- 215 km/h --- Corsair.Mk.I
12.95 km --- 3' 32" --- 220 km/h --- Corsair.Mk.II
12.75 km --- 3' 32" --- 217 km/h --- Corsair.Mk.IV

<hr class="ev_code_hr" />
USSR

08.25 km --- 3' 24" --- 146 km/h --- I-153M-62
08.23 km --- 3' 22" --- 147 km/h --- I-153P

07.40 km --- 2' 42" --- 164 km/h --- I-16.Type.18
07.47 km --- 2' 31" --- 178 km/h --- I-16.Type.24

10.64 km --- 3' 14" --- 197 km/h --- I-185M-71
10.70 km --- 3' 06" --- 207 km/h --- I-185M-82A

10.45 km --- 3' 09" --- 199 km/h --- MiG-3
10.79 km --- 3' 15" --- 199 km/h --- MiG-3ud
10.52 km --- 3' 08" --- 201 km/h --- MiG-3.Ubs
10.76 km --- 3' 22" --- 192 km/h --- MiG-3.ShVak
10.48 km --- 3' 15" --- 193 km/h --- MiG-3AM-38
11.11 km --- 3' 32" --- 189 km/h --- MiG-3U

10.64 km --- 3' 28" --- 184 km/h --- LaGG-3.Serie.4
10.72 km --- 3' 29" --- 185 km/h --- LaGG-3.Serie.29
10.71 km --- 3' 33" --- 181 km/h --- LaGG-3.Serie.35
10.71 km --- 3' 22" --- 191 km/h --- LaGG-3-IT
11.17 km --- 3' 33" --- 189 km/h --- LaGG-3.Serie.66

10.51 km --- 3' 29" --- 181 km/h --- La-5
10.57 km --- 3' 06" --- 204 km/h --- La-5F
10.55 km --- 3' 11" --- 199 km/h --- La-5FN

10.59 km --- 3' 08" --- 203 km/h --- La-7
10.59 km --- 3' 08" --- 203 km/h --- La-7.3xB-20

10.19 km --- 3' 04" --- 199 km/h --- Yak-1
10.43 km --- 3' 11" --- 197 km/h --- Yak-1b

10.02 km --- 3' 14" --- 186 km/h --- Yak-3
09.94 km --- 3' 08" --- 190 km/h --- Yak-3P

10.27 km --- 3' 06" --- 199 km/h --- Yak-7A
09.94 km --- 2' 57" --- 202 km/h --- Yak-7B

10.99 km --- 3' 26" --- 192 km/h --- Yak-9
10.44 km --- 3' 10" --- 198 km/h --- Yak-9B
10.53 km --- 3' 10" --- 200 km/h --- Yak-9D
10.60 km --- 3' 25" --- 199 km/h --- Yak-9K
10.31 km --- 3' 04" --- 202 km/h --- Yak-9M
10.29 km --- 3' 06" --- 199 km/h --- Yak-9T

09.06 km --- 2' 45" --- 198 km/h --- Yak-9U
09.04 km --- 2' 31" --- 216 km/h --- Yak-9UT

<hr class="ev_code_hr" />
GERMANY

09.21 km --- 2' 40" --- 207 km/h --- Bf-109E-4
09.02 km --- 2' 27" --- 221 km/h --- Bf-109E-4B
09.17 km --- 2' 36" --- 212 km/h --- Bf-109E-7
09.65 km --- 2' 40" --- 207 km/h --- Bf-109E-7Z

11.77 km --- 3' 09" --- 224 km/h --- Bf-109F-2
11.66 km --- 3' 04" --- 228 km/h --- Bf-109F-4

10.30 km --- 2' 53" --- 214 km/h --- Bf-109G-2
10.52 km --- 2' 52" --- 220 km/h --- Bf-109G-6
10.66 km --- 2' 53" --- 222 km/h --- Bf-109G-6.Late

10.45 km --- 2' 51" --- 220 km/h --- Bf-109G-6AS
10.44 km --- 2' 47" --- 225 km/h --- Bf-109G-14
10.12 km --- 2' 48" --- 217 km/h --- Bf-109G-10
10.08 km --- 2' 38" --- 230 km/h --- Bf-109K-4

12.63 km --- 3' 10" --- 239 km/h --- Bf-110G-2

10.84 km --- 3' 04" --- 212 km/h --- Fw-190A-4
10.69 km --- 2' 57" --- 217 km/h --- Fw-190A-5
10.84 km --- 3' 04" --- 212 km/h --- Fw-190A-6

10.43 km --- 2' 52" --- 218 km/h --- Fw-190A-8
10.44 km --- 2' 52" --- 219 km/h --- Fw-190A-9
10.51 km --- 2' 52" --- 220 km/h --- Fw-190F-8

11.26 km --- 3' 03" --- 221 km/h --- Fw-190D-9
11.23 km --- 3' 04" --- 220 km/h --- Fw-190D-9.Late
11.21 km --- 3' 09" --- 214 km/h --- Ta-152H-1

<hr class="ev_code_hr" />
IMPERIAL JAPANESE NAVY

10.49 km --- 3' 47" --- 166 km/h --- A6M2
10.59 km --- 3' 47" --- 176 km/h --- A6M2-21
09.12 km --- 3' 47" --- 145 km/h --- A6M2-N

10.42 km --- 3' 36" --- 174 km/h --- A6M3

10.43 km --- 3' 30" --- 179 km/h --- A6M5
10.42 km --- 3' 36" --- 174 km/h --- A6M5a
10.43 km --- 3' 45" --- 167 km/h --- A6M5b
10.30 km --- 3' 13" --- 192 km/h --- A6M5c

10.37 km --- 3' 25" --- 182 km/h --- A6M7-62
10.33 km --- 3' 30" --- 177 km/h --- A6M7-63

IMPERIAL JAPANESE ARMY

10.31 km --- 3' 39" --- 169 km/h --- Ki-43.Ia
10.26 km --- 3' 46" --- 163 km/h --- Ki-43.Ib
10.54 km --- 3' 58" --- 159 km/h --- Ki-43.Ic

10.60 km --- 3' 00" --- 212 km/h --- Ki-61.I.Hei
10.89 km --- 3' 03" --- 214 km/h --- Ki-61.I.Ko
10.84 km --- 3' 03" --- 213 km/h --- Ki-61.I.Otsu

12.38 km --- 3' 26" --- 216 km/h --- Ki-84.Ia
11.92 km --- 3' 11" --- 225 km/h --- Ki-84.Ib
12.15 km --- 3' 20" --- 219 km/h --- Ki-84.Ic

10.03 km --- 2' 57" --- 204 km/h --- Ki-100.I.Ko

<hr class="ev_code_hr" />
OTHER

08.61 km --- 2' 38" --- 196 km/h --- I.A.R.80
08.48 km --- 2' 34" --- 198 km/h --- I.A.R.81a
08.53 km --- 2' 32" --- 202 km/h --- I.A.R.81c

10.40 km --- 3' 36" --- 173 km/h --- P.11c

08.08 km --- 3' 18" --- 147 km/h --- Fiat.Cr.42

08.58 km --- 3' 00" --- 172 km/h --- Fiat.G.50

<hr class="ev_code_hr" />
Ranks:

<LI>16.89 km --- 4' 06" --- 247 km/h --- P-38J
<LI>13.52 km --- 5' 59" --- 136 km/h --- Gladiator.J8A
<LI>13.11 km --- 4' 10" --- 189 km/h --- P-40E
<LI>12.95 km --- 3' 32" --- 220 km/h --- Corsair.Mk.II
<LI>12.63 km --- 3' 10" --- 239 km/h --- Bf-110G-2
<LI>12.44 km --- 3' 32" --- 209 km/h --- F6F-3
<LI>12.38 km --- 3' 26" --- 216 km/h --- Ki-84.Ia
<LI>11.80 km --- 3' 20" --- 212 km/h --- P-47D-27
<LI>11.77 km --- 3' 09" --- 224 km/h --- Bf-109F-2
<LI>11.63 km --- 3' 18" --- 211 km/h --- FM2
<LI>11.34 km --- 3' 14" --- 210 km/h --- P-63C
<LI>11.26 km --- 3' 03" --- 221 km/h --- Fw-190D-9
<LI>11.21 km --- 3' 09" --- 214 km/h --- Ta-152H-1
<LI>11.17 km --- 3' 33" --- 189 km/h --- LaGG-3.Serie.66
<LI>11.11 km --- 3' 32" --- 189 km/h --- MiG-3U
<LI>10.99 km --- 3' 26" --- 192 km/h --- Yak-9
<LI>10.97 km --- 3' 25" --- 193 km/h --- P-39Q-10
<LI>10.89 km --- 3' 03" --- 214 km/h --- Ki-61.I.Ko
<LI>10.88 km --- 3' 36" --- 181 km/h --- Hurricane.Mk.Ia
<LI>10.70 km --- 3' 06" --- 207 km/h --- I-185M-82A
<LI>10.59 km --- 3' 08" --- 203 km/h --- La-7
<LI>10.59 km --- 3' 47" --- 176 km/h --- A6M2-21
<LI>10.58 km --- 3' 03" --- 208 km/h --- P-51C
<LI>10.54 km --- 3' 58" --- 159 km/h --- Ki-43.Ic
<LI>10.43 km --- 3' 36" --- 174 km/h --- Siptfire.Mk.Vb.CLP
<LI>10.40 km --- 3' 36" --- 173 km/h --- P.11c
<LI>10.03 km --- 2' 57" --- 204 km/h --- Ki-100.I.Ko
<LI>09.78 km --- 2' 53" --- 203 km/h --- F2A-2
<LI>08.61 km --- 2' 38" --- 196 km/h --- I.A.R.80
<LI>08.58 km --- 3' 00" --- 172 km/h --- Fiat.G.50
<LI>08.25 km --- 3' 24" --- 146 km/h --- I-153M-62
<LI>08.08 km --- 3' 18" --- 147 km/h --- Fiat.Cr.42
<LI>07.47 km --- 2' 31" --- 178 km/h --- I-16.Type.24



Takata.
(edit: added infos)

FritzGryphon
06-26-2005, 08:20 PM
What's the starting alt, btw?

Another thing, I'm pretty sure best glide speed is a lot higher than 210km/h.

WWMaxGunz
06-26-2005, 08:21 PM
Are all the best glides so close to stall speed?

FritzGryphon
06-26-2005, 08:27 PM
Oh, no. If anything, they are close to best climb. Looking for the info now.

Not P-51, but still good.:

http://www.eaa32.org/Articles/Aerodynamic.html

glide at your best glide speed (this is once again about the airspeed for maximum climb rate at full power)

(Acrolite Triplane) Best glide speed 55 mph. ... Best rate of climb speed 60 mph

(Acrolite 1B) Best glide speed 75 mph... Best climb rate speed 80 mph

So best glide for P-51 would be 250km/h or so. (IAS)

Takata_
06-26-2005, 08:31 PM
Originally posted by FritzGryphon:
What's the starting alt, btw?
Yep, sorry!
starting alt : 1000 m (999 m when plane is spawning)
starting speed : 300 km/h (242-244 km/h TAS when plane is spawning)


Another thing, I'm pretty sure best glide speed is a lot higher than 210km/h.
this result is a linear TAS achieved.
I tried a wide range of speed and those were my best distance at such speed.

Takata_
06-26-2005, 08:41 PM
Originally posted by WWMaxGunz:
Are all the best glides so close to stall speed?

Yes, all the best glide are at very low speed, it was not what I expected.

FritzGryphon
06-26-2005, 08:44 PM
all the best glide are at very low speed


No, all best glide are close to best climb. Like I said, for the P-51 it'd be about 250km/h. I'm surprised it's so low in the game.

Takata_
06-26-2005, 08:54 PM
Originally posted by FritzGryphon:
Like I said, for the P-51 it'd be about 250km/h. I'm surprised it's so low in the game.

One may think that the best climb speed may be much lower than real one too?

Here is an example with different speeds for G-50:
8.07 km 2'27" 198 km/h
8.31 km 2'33" 196 km/h
8.46 km 2'41" 189 km/h
8.58 km 3'00" 172 km/h
8.50 km 3'06" 164 km/h

Takata_
06-26-2005, 09:16 PM
so what should make the difference between two planes? Wingloading? aerodynamics? wing profile?

Takata

Takata_
06-26-2005, 10:16 PM
(edited -> included in first post)

Takata_
06-26-2005, 11:33 PM
(edited -> included in first post)

Hurri-Khan
06-26-2005, 11:36 PM
Originally posted by Takata_:

Here is an example with different speeds for G-50:
8.07 km 2'27" 198 km/h
8.31 km 2'33" 196 km/h
8.46 km 2'41" 189 km/h
8.58 km 3'00" 172 km/h
8.50 km 3'06" 164 km/h

G.50's glide ratio was about 9. The best climb speed is mentioned to be about 210-220 km/h IAS. Try setting prop pitch to low and use that speed. If you want another test; glide ratio in landing configuration ( flaps&gear down ) was 5-6 with 180 km/h IAS.

Dunno about J8A, but Bristol Bulldog's ( similiar biplane with fixed gear and two blade fixed prop ) glide ratio was around 6,3 in 115-130 km/h IAS.

Biplanes seem indeed to glide too much.. try I-153 with landing gear retracted and prop pitch set to low, it might make a new record for ya http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif


<--H-K-<<<

Takata_
06-26-2005, 11:59 PM
Originally posted by Hurri-Khan:
Try setting prop pitch to low and use that speed. If you want another test; glide ratio in landing configuration ( flaps&gear down ) was 5-6 with 180 km/h IAS.

Dunno about J8A, but Bristol Bulldog's ( similiar biplane with fixed gear and two blade fixed prop ) glide ratio was around 6,3 in 115-130 km/h IAS.

Biplanes seem indeed to glide too much.. try I-153 with landing gear retracted and prop pitch set to low, it might make a new record for ya http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

S~!
I have set propeller pitch to zero percent or fully feathered when it was available (the Gladiator J8A is able to feather his propeller as well as P-38).

Gear is always retracted, no flaps and I'm trying to generate the maximum lift. I made the test for I-153, but again, it was not the result expected.

(edited -> included in first post)

bolillo_loco
06-27-2005, 12:22 AM
how about the hortan brother's bat wing?

Takata_
06-27-2005, 12:37 AM
Originally posted by bolillo_loco:
how about the hortan brother's bat wing?
Sorry, I didn't test any jet.

(edited -> included in first post)

BBB_Hyperion
06-27-2005, 12:57 AM
Is it just me or do most glide too good ?

Takata_
06-27-2005, 01:02 AM
Originally posted by BBB_Hyperion:
Is it just me or do most glide too good ?

I wish I could find something logical about that...

(edited -> included in first post)

NonWonderDog
06-27-2005, 01:17 AM
Well, if the G-50's glide ratio is in fact ~9, and you're getting 8.6, it's not that far off. I don't know about the Mustang, though. It doesn't look like most glide much better than they're supposed to, but I don't have any figures.

The P-38 is surprising, but I don't know either way. Wait, 13.5 for the gladiator?!?!

Takata_
06-27-2005, 01:25 AM
Originally posted by NonWonderDog:
It doesn't look like most glide much better than they're supposed to, but I don't have any figures.

I don't have any figures aswell.

(edited -> included in first post)

NonWonderDog
06-27-2005, 01:33 AM
I think the Targetware site said the P-51 has a glide ratio of 15:1 (!!), if it means anything. There's another site that quotes "three miles per 1,000 feet," which is about 15.8:1. I don't know, does "slightly better than a rock" translate into 75% as good as an assault glider?

Starting the Gladiator at 300 km/h probably has an impact on the results, though.

Takata_
06-27-2005, 01:50 AM
Originally posted by NonWonderDog:
"slightly better than a rock"
this is how I-16 glide http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif


Starting the Gladiator at 300 km/h probably has an impact on the results, though.
300 km/h is set in mission, but planes are spawning with a speed of =~ 244 km/h TAS. Gladiator don't bleed energy or lose altitude for long long time. I made it glide close to 7 mn!

(edited -> included in first post)

Takata_
06-27-2005, 02:24 AM
(edited -> included in first post)

BBB_Hyperion
06-27-2005, 02:34 AM
Well the best climbspeed should indeed be very close to the best glide speed.

When we take a best climb figure for example for the g2 is 270 kph . I assume its ias in the finnish g2 translation cause it wouldnt make sense to give it in tas .

Then the 214 km/h tas is somewhat low.

BBB_Hyperion
06-27-2005, 02:38 AM
Does anyone remember how to determine best climb i remember using polars of cl cd and overlay them something in this direction.

Takata_
06-27-2005, 03:51 AM
(edited -> included in first post)

Kernow
06-27-2005, 05:48 AM
Originally posted by BBB_Hyperion:
Does anyone remember how to determine best climb

I use the graphs in IL-2C. Look for the peak rate of climb in the Sea-level RoC v TAS graph. Il-2C not updated for 4.01 yet - still 3.04 - but I don't think the changes to the FMs would change this sort of info. Torque might have been added but I don't think any peformance figures were changed.

I use best climb speed when I have to glide. Also close the radiator, feather the prop or go to coarse pitch. Seems to work quite well.

BBB_Hyperion
06-27-2005, 06:57 AM
You cant proof sim data with sim data kernow http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

Cause the data we have does look quite through all planes too low in values . Best climb should be close to best glide where best glide is some km/h slower around 25+- km/h depending on planetype.

When we take some original plane manual data we see it doesnt fit glide speed is too high.

Example g2 270 km/h best climb best glide 245 +- km/h . Now result is 214 Tas .

In Ilcompare we find the 270 best climb vs tas too but i am not sure it is right cause when its in the manual it needs to be gauge readable for the pilot and only very late gauges had tas conversion. Anyway most best glide speeds seem 30 % throughout all planes too low .

I didnt test em myself yet cause i think Takata did very good tests and surely spend some time on this tests ,explained his setup well enough that we can believe he knows what he is testing.

What i was up to is a method of determing best glide graphicaly with cl cd values but cant remember how it was done . With 1 or 2 example planes counterchecked this way we would have an at least a reference speed.

Chuck_Older
06-27-2005, 07:04 AM
Originally posted by Takata_:
... designed by North-American.

But, the Gladiator J8A a much better glider, engine off, than the P-51.

- Here's my best glide with P-51s' & J8A:

Crimean map, 12h
wind/turbulences turned off
Alt : 1000 m (mission setting)
Speed : 300 km/h (mission setting)
fuel: 0% (mission setting)
ammo: empty (mission setting)

Distance is reccorded from starting point to crash point; average speed is calculated from distance and flight time; error margin =~ 1% (100m / 10 km).

Plane Distance Flight Speed
P-51B 10.54 km 3'00" 211 km/h
P-51C 10.58 km 3'03" 208 km/h
Mustang III 10.58 km 2'55" 218 km/h
P-51D-5NT 10.49 km 2'56" 215 km/h
P-51D-20NA 10.49 km 2'53" 218 km/h
GladiatorJ8A 13.52 km 5'59" 136 km/h

May someone explain me what makes a plane glide, and why the Gladiator distance is 30% better than the P-51?

Takata

You're basing what was best in real life performance in the areas you mention....by using data from a PC simulation

In Real life, Gloster and NAA didn't run their planes up to Xm on the Crimea map http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

JG27_Stacko
06-27-2005, 10:11 AM
Originally posted by Takata_:
... designed by North-American.



Actually designed by a self-taught German immigrant... Bet you didn't know that!

Chuck_Older
06-27-2005, 10:19 AM
Originally posted by JG27_Stacko:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Takata_:
... designed by North-American.



Actually designed by a self-taught German immigrant... Bet you didn't know that! </div></BLOCKQUOTE>


Not this 'P-51 was a German design' thing again

Firstly, Edgar Schmued didn't design the whole thing. Secondly, he worked for NAA, an American company. The P-51 is an American design.

Let's please not start this foolishness again

Slickun
06-27-2005, 12:02 PM
An American design, worked on by a German immigrant, and finally brought to its potential by an English engine.

Kinda unique.

lrrp22
06-27-2005, 12:24 PM
Originally posted by Slickun:
An American design, worked on by a German immigrant, and finally brought to its potential by an English engine.

Kinda unique.

Typically American though... http://forums.ubi.com/images/smilies/25.gif

LStarosta
06-27-2005, 12:35 PM
You're just jealous.

God Bless the USA.

Takata_
06-27-2005, 12:47 PM
ok, I edited this thread tittle as everybody should notice that I really don't care about who designed the P-51, the name and nationality of his first girlfriend, and if she was overmodelled somewhere.

Takata.

Capt_Pepper
06-27-2005, 01:48 PM
Hehehehe.....Good answer,Takata!!!

Great information here and thanks for your efforts!! Good to see you're still active.
You've always been a great pilot as well as an asset to the community....I hope all is well with you.

anarchy52
06-27-2005, 01:58 PM
Originally posted by NonWonderDog:
I think the Targetware site said the P-51 has a glide ratio of 15:1 (!!), if it means anything. There's another site that quotes "three miles per 1,000 feet," which is about 15.8:1. I don't know, does "slightly better than a rock" translate into 75% as good as an assault glider?


Modern sport gliders have about 30-ish

16:1 for a WWII fighter does not sound right...

Chuck_Older
06-27-2005, 03:21 PM
I am looking at an F-51D pilot's flight handbook at the moment. This hanbook covers Mustangs with the N-9 gunsight, called "early" models, so this info should apply to P-51Ds as well

Best power off glide spped: 175 mph IAS. The aircaft will glide approximately 14.5 statute miles for every 5000 feet altitude in no- wind conditions, no external load, gear and flaps up

This was published under the authority of the Secretary of the Air Force on July 15th, 1952, so I guess you could take this as "offcial information". Actually, it was restricted info in 1952 http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif T.O. no. 1F-51D-1 in case anyone's interested, formerly AN 01-60JE-1 for cross reference

In FB, fuel load location may make accurate testing difficult since we can't change CG by selecting tanks in a P-51

Kernow
06-27-2005, 03:47 PM
Originally posted by BBB_Hyperion:
You cant proof sim data with sim data kernow http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif



I wasn't really trying to prove it - just trying to find the best climb speed as determined by the sim FMs http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Those I've checked against actual best climb speeds seem reasonable. I seem to remember something about best climb and best glide speeds being very close (I think best climb speed is pretty much a constant TAS, so in IAS terms it drops with alt). However, who knows if best glide speed is indeed same as best climb speed in the game; Takata's tests indicate they may well not be.

Think I'll stick with the best climb speed, as that ought to work and no doubt one day it will work that way. It feels quite comfortable in most ac gliding at that speed and is a decent margin above the stall.

Takata_
06-27-2005, 03:51 PM
Originally posted by Chuck_Older:
In FB, fuel load location may make accurate testing difficult since we can't change CG by selecting tanks in a P-51

As this test is performed with perfectly empty fuel tanks, I don't really bother about selecting tanks. Anyway, thanks for the info, I'll try to figure out what kind of mesure this imperialish stuffish means in real metric system... http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

Have you got an "empty weight" quoted for this plane please?

Takata

Takata_
06-27-2005, 04:03 PM
Originally posted by Capt_Pepper:
...I hope all is well with you.
S~! Pepper,
and thank you! everything is fine for me at the moment, even if I'm not flying on-line as much as in the past, (at least at the moment!)

http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif Takata

Takata_
06-27-2005, 08:04 PM
(edited -> included in first post)

NonWonderDog
06-27-2005, 08:05 PM
Originally posted by Chuck_Older:
Best power off glide spped: 175 mph IAS. The aircaft will glide approximately 14.5 statute miles for every 5000 feet altitude in no- wind conditions, no external load, gear and flaps up


So a 15:1 glide ratio at 280 km/hr IAS?

That's it. No one is *ever* allowed to say that the Mustang doesn't burn energy fast enough.

Takata_
06-28-2005, 09:52 AM
Test completed for all fighters.
-> see resultats in this thread's first page

Takata

Chuck_Older
06-28-2005, 11:25 AM
OK. SO I have a question.

what does this:
"10.02 km --- 3' 14" --- 186 km/h --- Yak-3"

really mean?

3' 14" Means: three feet 14 inches. What are you trying to indicate using these symbols?

I am quite confused

As to the empty weight of the P-51D- they don't list an empty weight. They list a weight of 9,000 pounds for weight with no external stores, so subtract fuel at a weight of approximately 6 lbs per gallon for an estimate

KrasniyYastreb
06-28-2005, 11:29 AM
I don't see why the results would be surprising. The gliding range is determined by height, the parasitic(friction) drag, the aspect ratio (span/chord) of the wing, and the lift distribution along the span.

The aspect ratio and the lift distribution affect the induced(due to lift) drag coefficient. The most efficient wing is one that has a high aspect ratio and an elliptical lift distribution(which is almost never the case.)

Considering the combination of factors involved, and that the P-51 wasn't exactly built to be a glider, it does not seem out of the ordinary that other planes glide better.

Takata_
06-28-2005, 11:57 AM
Originally posted by Chuck_Older:
OK. SO I have a question.

what does this:
"10.02 km --- 3' 14" --- 186 km/h --- Yak-3"
really mean?
3' 14" Means: three feet 14 inches. What are you trying to indicate using these symbols?


3'14" mean 3 minutes and 14 seconds.
that's the total gliding time from spawn to crash used with distance to calculate the average gliding speed.

Takata

NonWonderDog
06-28-2005, 11:58 AM
Originally posted by Chuck_Older:
3' 14" Means: three feet 14 inches.

It can also mean three minutes 14 seconds. I think that's what he probably means.


The P-51's not built to be a glider, but every source gives a glide ratio of 15:1, including the pilot's manual. That would be 15 km forward for every 1,000 meters down. While it doesn't seem to be much of a problem since all the planes glide in the same range, being out-glid by the Gladiator is just plain wrong.

You might want to try the P-51 at full fuel, though, just to see what would happen.

Takata_
06-28-2005, 12:41 PM
Originally posted by KrasniyYastreb:
I don't see why the results would be surprising. The gliding range is determined by height, the parasitic(friction) drag, the aspect ratio (span/chord) of the wing, and the lift distribution along the span.
S~! KraniyYastreb
Thanks for the gliding infos.
This test result is surprising on several points, mainly about the very low best gliding speed and the plane's gliding performance relative to each others. The starting height is the same for all, but what about the plane weight and the total wing area, isn't it an important factor to?

Originally posted by KrasniyYastreb:
The aspect ratio and the lift distribution affect the induced(due to lift) drag coefficient. The most efficient wing is one that has a high aspect ratio and an elliptical lift distribution(which is almost never the case.)
Aside from the aspect ratio, any plane is supposed to generate the maximum lift at one given speed and what I realised making the test is that the maximum lift for almost all planes is reached close to the maximum wing AoA on the edge of stall.
Some planes are gliding nose-up with full elevators trim and do not generate any drag to reduce the maximum gliding distance.
- example with F6F-3
1. at average 167 km/h - 4 mn 30 sec flight => 12,500 m covered. (elevators fully trimmed)
2. at average 211 km/h - 3 mn 32 sec flight => 12,440 m covered.
IMHO, any plane gliding with such AoA should induce a huge drag.

Originally posted by KrasniyYastreb:
Considering the combination of factors involved, and that the P-51 wasn't exactly built to be a glider, it does not seem out of the ordinary that other planes glide better.
Do not focus on P-51 result, it doesn't really matter.

Takata.

Takata_
06-28-2005, 12:46 PM
Originally posted by NonWonderDog:
You might want to try the P-51 at full fuel, though, just to see what would happen.

More weight => shorter glide... I tried with full fuel load, and even with bombs... http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

Takata

NonWonderDog
06-28-2005, 01:17 PM
Originally posted by Takata_:
Aside from the aspect ratio, any plane is supposed to generate the maximum lift at one given speed and what I realised making the test is that the maximum lift for almost all planes is reached close to the maximum wing AoA on the edge of stall.

That part's correct. Max lift is created at critical AoA. The problem is that a greater proportion of drag is created at the critical AoA. Lift varies linearly with AoA (up to the critical angle), induced drag varies with AoA^2. (It also varies with lots of other things. Drag gets awfully complicated.)

Parasitic drag varies with the square of velocity. It's pretty much just friction.

Best glide speed is the speed where the lift/drag ratio is maximized. It seems like a graph of lift/drag might be a bit flatter than it should be, if what you're saying is true...

Takata_
06-28-2005, 01:57 PM
Originally posted by NonWonderDog:
Best glide speed is the speed where the lift/drag ratio is maximized. It seems like a graph of lift/drag might be a bit flatter than it should be, if what you're saying is true...
The other weirditical-factor is that it's not modeled the same for all. I would assume this lift/drag ratio to be part of the physics modeled in the sim, but, planes behave differently. Some, like Fw-190s' are gliding better with the highest AoA, ohters, like P-38 really need to keep some speed to make an long distance run. http://forums.ubi.com/images/smilies/blink.gif

Takata.

Chuck_Older
06-28-2005, 02:53 PM
You sure about the 3'14" thing? That really does reads 4 feet 2 inches to most folks

In racing, that would be 3:14.00 http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

Takata_
06-28-2005, 03:03 PM
Originally posted by Chuck_Older:
You sure about the 3'14" thing? That really does reads 4 feet 2 inches to most folks
I'm one folk with only one foot per leg, and yes, I'm sure those symbols are for minutes and seconds, at least in civilized countryland where stones aren't used anymore to weight anything http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

Takata.

KrasniyYastreb
06-28-2005, 03:21 PM
Flight dynamics can be confusing and a little counter-intuitive. The lift/drag ratio is determined by the aerodynamics of each plane, which are different.


Originally posted by Takata_:

The starting height is the same for all, but what about the plane weight and the total wing area, isn't it an important factor to?

The weight and wing area actually come into the best glide speed. Best glide speed, among other things, is directly proportional to the square root of the weight, and inversely proportional to the square root of the wing area.

However, if one goes through the derivation for gliding range (which I will spare everybody for now), you will see that the speed actually cancels out! This makes sense because since the plane is descending at some angle, a higher speed results in both a higher ground speed and a higher vertical speed - so less time in the air. In the end the plane should travel the same distance.

The fact that you tested all the planes empty might explain why the glide speeds seem a little low. An interesting thing to try would be to pick a plane, divide the glide speed you found in your tests by the square root of the empty weight and multiply by the square root of the fully-loaded weight(without external stores) to obtain a new glide speed. Then repeat the test with the loaded plane, but fly at the higher speed and see if you travel the same distance.

I am curious as to what the result would be...

Hope this helps.

Takata_
06-28-2005, 04:37 PM
Originally posted by KrasniyYastreb:
The fact that you tested all the planes empty might explain why the glide speeds seem a little low. An interesting thing to try would be to pick a plane, divide the glide speed you found in your tests by the square root of the empty weight and multiply by the square root of the fully-loaded weight(without external stores) to obtain a new glide speed. Then repeat the test with the loaded plane, but fly at the higher speed and see if you travel the same distance.
I am curious as to what the result would be...
Yes, this helps!
I'll try to test it with a fully loaded plane (fuel+ammo). I already made some experimentation about that and I concluded that I was not able reach the same range, but I'll try it again and keep the result.


"Il semble que la perfection soit atteinte non quand il n'y a plus rien √ ajouter, mais quand il n'y a plus rien √ retrancher. "
St. Exupery a sans doute déjà testé le vol sans moteur et il savait de quoi il en retourne... http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

Takata.

Jetbuff
06-28-2005, 08:58 PM
Correct me if I'm wrong, but wouldn't these results support the theory that the induced drag in FB is rather low and possibly increases in a linear fashion as opposed to an exponential one?

I don't want to jump to conclusions but it would explain quite a bit about the eternally disputed E-bleed modelling. If I were to jump to a conclusion, it would be that induced drag is not rising exponentially with AoA as it should and to balance out plane performance in terms of speed/climb what have you some other factors were "fudged" to get the planes to perform plausibly relative to each other.

But enough speculation, I'd like to hear from the experts. It's a real shame Oryx no longer visits these boards.

Chuck_Older
06-29-2005, 06:42 AM
Originally posted by Takata_:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Chuck_Older:
You sure about the 3'14" thing? That really does reads 4 feet 2 inches to most folks
I'm one folk with only one foot per leg, and yes, I'm sure those symbols are for minutes and seconds, at least in civilized countryland where stones aren't used anymore to weight anything http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

Takata. </div></BLOCKQUOTE>

http://forums.ubi.com/images/smilies/10.gif
3' 14" would be used in navigation, right?

Takata_
06-29-2005, 09:03 AM
this thread continue here, where it's started but Crazyvan disliked the tittle (http://forums.ubi.com/eve/forums/a/tpc/f/63110913/m/9921072433)

Chuck_Older: yes, beside any time and angle mesurement.

JetBuff: yes, maybe you jump a bit too far but I suspect something related with that too.

KrasniyYastreb : you can see the result of few testing made with fully loaded P-40E in ORR, link above.

And please all, let this one sink...
S~
http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif Takata