Hawker Tempest turning performance

[ZachariasX]

47 minutes ago, Mitthrawnuruodo said:

The stall speeds could be given on a completely arbitrary scale without any real harm.

I used 10 mph as correction, if you assume 25 then it doesn‘t produce significant alterations in getting a ballpark of what to expect.

 

My main point is that even in clean, all up configuration, actual Clmax is not always the same, it depends on power setting and airspeed (not even taking Mach effects into account) due to prop slipstream effects. You can fly slower, nose higher up at high power than if you were gliding. There‘s more context to stall speed than only PEC.

 

55 minutes ago, unreasonable said:

To get to Holtzauge's 1.10 (plausible if the airfoil data is correct) you would need 110mph - so +30%   I find that surprisingly high,

I don‘t. Slow flight with power applied gives you a different slipstream assist than if you were gliding. You land the Tempest with considerable power applied. Power off approach is different. That should make a real difference in lift. I have to find the report with the Hellcat, where they actually measured the difference, but I remember it to be about 30%. A lot. We had that report floating in one of those Crumpp discussions...

 

57 minutes ago, unreasonable said:

given the 109's exceptionally high critical AoA,

That one has electrolytes, and that‘s all the body needs.

 

Other than that, sure. Agree.

 

1 hour ago, Bremspropeller said:

The ASI could be reading Mach 3 and I wouldn't notice.

You WOULD. There‘s lots of folks of whom I‘m certain that they wouldn‘t. Not you.

[unreasonable]

6 hours ago, ZachariasX said:

 

 

You land the Tempest with considerable power applied. Power off approach is different. That should make a real difference in lift. I have to find the report with the Hellcat, where they actually measured the difference, but I remember it to be about 30%.

 

 

The Tempest PN says for beam approach: at 150 feet, throttle back slowly to zero boost, slight nose down, IAS 110-115. If stall is at 75mph in landing configuration and you are still descending nose down and decelerating at 110 that does not indicate considerable power to me, but what is "considerable". 

 

As to power on vs power off: several Hellcat test reports are here; http://www.wwiiaircraftperformance.org/f6f/f6f.html

 

The difference in the on-off clean configuration stall is fairly consistent, at ~2mph lower power on in most cases. Using those speeds uncorrected with the weights in the test reports, gives a increase in CLmax power on from  ~1.47 to 1.53 ie about 4%,  nowhere near 30%   There is nothing here that suggests that power on makes a massive difference to clean CLmax.  The difference in landing configuration is somewhat bigger: 4-7 mph on different tests. So you go from, for example, 1.96 to 2.27, a 16% increase. In my primitive brain that says that the flaps "catch" much more of the propeller effect  than the wing.

 

Tech specs do not actually state whether the speeds given are power on or off, although the consistency (usually less than 1%) of the high and low weight/speed pairings strongly suggests that they are measured the same way for the speed range. I have always assumed that these were power off, but more importantly, that whether on or off they are done the same way for all the planes in the data set. If that is correct, it does not matter so much whether they are power on or off for this particular case: the Tempest is still an anomaly.

 

 

 

 

 

Edited November 24, 2020 by unreasonable

[JtD]

Three sets of figures that come to my mind:

 

Hurricane from NACA testing: clean/off: 1.31 clean/on: 1.92 dirty/off: 2.00 dirty/on: 2.40

Spitfire from NACA testing: clean/off: 1.18 clean/on: 1.63 dirty/off: 1.51 dirty/on: 1.99

Hellcat from NACA testing: clean/off: 1.4 clean/on: 2.1 dirty/off: 2.2 dirty/on: 3.0

 

Mind you, power settings varied. In terms of speeds these are about 10-15 mph difference.

[Mitthrawnuruodo]

2 hours ago, unreasonable said:

Tech specs do not actually state whether the speeds given are power on or off, although the consistency (usually less than 1%) of the high and low weight/speed pairings strongly suggests that they are measured the same way for the speed range. I have always assumed that these were power off, but more importantly, that whether on or off they are done the same way for all the planes in the data set. If that is correct, it does not matter so much whether they are power on or off for this particular case: the Tempest is still an anomaly.

 

The specs seem consistent with in-game tests done at idle (or nearly idle). Testing at high power settings gives very different results (for example, the in-game Tempest can climb at around 80 mph with full power, well below the listed stall speeds).

 

10 hours ago, unreasonable said:

In the game, no plane stalls at a speed as low as noted in PNs, AFAIK.

 

They are all over the place, even just looking at the clean stall speeds of British aircraft. Some are close to the PN speeds, while others are much higher. I don't know how to make sense of it.

 

Hurricane: 80 - 90 mph PN, 82 - 97 mph in-game (+2 to +8 %)

Spitfire V: 73 mph PN, 85 - 90 mph in-game (+16 to +23 %)

Spitfire IX: 90 - 100 mph PN*, 89 - 102 mph in-game (-1 to +2 %)

Tempest V: 85 mph PN, 94 - 109 mph in-game (+10 to +28  %)

 

It seems that a "reduced CLmax" Tempest would have the greatest discrepancy between PN and in-game stall speeds of any British aircraft.

 

Whatever happens to the Tempest, it will be interesting to see how the Typhoon is handled when it is introduced for Normandy. It has similarly low stall speeds in the PN, so it's possible that we'll get another aircraft with a very high CLmax. Alternatively, a Typhoon with a CLmax in line with most other aircraft could give us a strange situation where the Tempest dramatically outperforms the Typhoon w.r.t. maximum lift.

 

*Pilot's Notes for Spit IX specify "engine off" with "clipped" wings. "Full span" wings have stall speeds reduced by 3 - 6 mph. Pilot's Notes for the other aircraft do not specify the power conditions for the given stall speeds.

Edited November 24, 2020 by Mitthrawnuruodo

[Holtzauge]

 

I did some tests in Mark Drela’s Xfoil program to test the effects of the Reynolds number since the airfoiltools.com chart for the Tempest profile only goes up to Re=1E6. The Re for the Tempest when landing is way higher than 1E6 (over 5E6) and in general a higher Re gives a higher Clmax. Turns out this made all the difference: The 2D Clmax for the Tempest goes up from 1.2 to about 1.47 at 16 deg alfa (See picture below).

 

For comparison, NACA23012 gives a 2D Clmax of 1.75 at that Re in Xfoil. At first I thought that Xfoil was overestimating the Clmax but when I checked NACA’s own estimate in the book Theory of wing sections by Abbot & Doenhoff they state about the same for Re=6E6.

 

So a revised estimate using the 1.35 aircraft Clmax for NACA230-series planes in power off conditions as a base:

 

Clmax=1.35*1.47/1.75=1.13

 

Maybe one could argue that since the pressure differential is lower on a 3D wing when the 2D Clmax is lower as for the Tempest profile and doing a straight linear estimate is a bit pessimistic so maybe a Clmax=1.2 or thereabouts could be more realistic?

 

Anyway, even a Clmax of 1.2 is way lower than the 1,52 we seem to have today in-game.

 

[unreasonable]

4 hours ago, Mitthrawnuruodo said:

 

The specs seem consistent with in-game tests done at idle (or nearly idle). Testing at high power settings gives very different results (for example, the in-game Tempest can climb at around 80 mph with full power, well below the listed stall speeds).

 

 

They are all over the place, even just looking at the clean stall speeds of British aircraft. Some are close to the PN speeds, while others are much higher. I don't know how to make sense of it.

 

Hurricane: 80 - 90 mph PN, 82 - 97 mph in-game (+2 to +8 %)

Spitfire V: 73 mph PN, 85 - 90 mph in-game (+16 to +23 %)

Spitfire IX: 90 - 100 mph PN*, 89 - 102 mph in-game (-1 to +2 %)

Tempest V: 85 mph PN, 94 - 109 mph in-game (+10 to +28  %)

 

It seems that a "reduced CLmax" Tempest would have the greatest discrepancy between PN and in-game stall speeds of any British aircraft.

 

Whatever happens to the Tempest, it will be interesting to see how the Typhoon is handled when it is introduced for Normandy. It has similarly low stall speeds in the PN, so it's possible that we'll get another aircraft with a very high CLmax. Alternatively, a Typhoon with a CLmax in line with most other aircraft could give us a strange situation where the Tempest dramatically outperforms the Typhoon w.r.t. maximum lift.

 

*Pilot's Notes for Spit IX specify "engine off" with "clipped" wings. "Full span" wings have stall speeds reduced by 3 - 6 mph. Pilot's Notes for the other aircraft do not specify the power conditions for the given stall speeds.

 

I agree there is quite a bit of variation but you have to take the weights and PEC into account before comparing. When you do so, most of the game's values become more understandable and plausible given what we have about the airfoil CLs. For instance:

 

Hurricane MkII PN says 80-90mph at 7600-9200lbs: ie 3448kg minimum compared to the game's 2859kg. The Hurricane PN would give a CL max range of 1.72 to 1.80 with uncorrected speed, compared to 1.40-1.42 in game. The PN gives a PEC from 100-120 mph as + 4  Given the trend line, a reasonable straight line extrapolation for 80-100mph would be +6  which would give you 86-96mpg, and now very similar to the game's speed range but still a higher CLmax due to the lower weight range.

 

If you think the PEC line is actually a curve, and add +10 correction you get 1.39-1.42: now close to the game's results (which are still a bit too high, I suspect).

 

For the Spitfire V the PN says 73mph at 6400lbs clean. PEC chart is +4 at 100-140, so same drill: uncorrected = 1.94 compared to game's 1.33-1.34

Addin +6 and you get 1.66, to get to the game's range you need +15mph 

 

While it is hard to reconcile the game's results to the data as stated, once you allow for weight and add in PEC based on the assumption that the PEC line tilts up sharply at low speeds, most of the game's results start to become much more consistent.  

 

Posted before, but worth showing again:

 

 

 

Edited November 24, 2020 by unreasonable

[HawkerMkIII_]

8 hours ago, Mitthrawnuruodo said:

 

 

 

Whatever happens to the Tempest, it will be interesting to see how the Typhoon is handled when it is introduced for Normandy. It has similarly low stall speeds in the PN, so it's possible that we'll get another aircraft with a very high CLmax. Alternatively, a Typhoon with a CLmax in line with most other aircraft could give us a strange situation where the Tempest dramatically outperforms the Typhoon w.r.t. maximum lift.

 

 

Weirdest thing is that the Typhoon actually turned better than the Tempest, so it would be even more weird that the Typhoon has a correct flight model but the Tempest doesn't

 

[ZachariasX]

The Typhoon uses AFAIK a NACA 22 profile with a Clmax of around 1.5.  The wing we have for the Tempest is about what I would expect as ballpark for the Typhoon.

[HawkerMkIII_]

Well, I hope the developers read this and take it into consideration. Thanks to everyone that contributed into this post, I think there's enough things now prove that the Tempest didn't turn like that in real life, if you have anything to add you're free to do so! Thanks again to everyone for your time and help.

Edited February 8, 2021 by -332FG-Razor_

[HawkerMkIII_]

New update and nothing about .50 calibers or the Tempest's flight model... Amazing.

[Aurora_Stealth]

To be honest, from what I've read on the forums today (not got access to my gaming PC atm) - it looks like the new update has caused major issues/disruption to how the damage model is meant to work and certain calibres of weapons are apparently ineffective. I would imagine the team are probably trying to diagnose that.

 

Don't forget also we're still in the holiday period, it will take time for them to assess this.

[HawkerMkIII_]

2 hours ago, Aurora_Stealth said:

 

Don't forget also we're still in the holiday period, it will take time for them to assess this.

That's true. Sorry for my my ignorance!

[Aurora_Stealth]

17 hours ago, HawkerMkIII said:

That's true. Sorry for my my ignorance!

 

No worries, we're all itching to see these things dealt with.

[II/JG17_HerrMurf]

9 minutes ago, -332FG-Razor_ said:

Hello guys, I'd like to share this bit of information I found. I doubt it will solve anything, but at last to add more information/proof. 



This is the source https://en.wikipedia.org/wiki/Hawker_Tempest#Air_combat_success_ratio in the ''other activities'' part.

Happy day

Razor.

Ha, I'd love it if the Tempest performed similar to the P-47..................not that I trust Wiki in the first place. It massively outperforms the Jug at low level and probably doesn't match well at altitude (haven't tried it) to what we have in game.

[HawkerMkIII_]

22 minutes ago, II/JG17_HerrMurf said:

Ha, I'd love it if the Tempest performed similar to the P-47..................not that I trust Wiki in the first place. It massively outperforms the Jug at low level and probably doesn't match well at altitude (haven't tried it) to what we have in game.

Yeah, I just read the original source... It says it ran circles around the P47, but it was slightly inferior to the P51D... I was wrong. You shouldn't trust Wikipedia.

 

Here's the original source if you're wondering, and here's the link to download the book that says it https://b-ok.lat/book/755164/d84c99?dsource=recommend&regionChanged=&redirect=200333741

Edited March 3, 2021 by -332FG-Razor_

[HawkerMkIII_]

Hello guys, on one of the book I'm reading about the Tempest, some specifications showed up and said minimum speed is 160 mph, Is it the stall speed? Maybe minimum recommended speed? Maybe minimum speed for proper flight/maneuvers? 
 

It's weird because the USAAF test said that it was 90mph with a clean configuration, but the other technical data says it's 160 with the flaps down, which I'm guessing it's from the RAF flight testing.

Edited March 8, 2021 by -332FG-Razor_

[jollyjack]

To Flap or not to Flap ..... yesterday i tried a P38, with flaps about 30% it seems to turn tighter ..

Edited March 8, 2021 by jollyjack

[Aurora_Stealth]

1 hour ago, -332FG-Razor_ said:

Hello guys, on one of the book I'm reading about the Tempest, some specifications showed up and said minimum speed is 160 mph, Is it the stall speed? Maybe minimum recommended speed? Maybe minimum speed for proper flight/maneuvers? 
 

It's weird because the USAAF test said that it was 90mph with a clean configuration, but the other technical data says it's 160 with the flaps down, which I'm guessing it's from the RAF flight testing.

 

Just my five cents here...

 

160mph sounds too high to me to be its stall speed, but sounds a lot like the minimum maneuvering speed, which gives a large margin (typically x1.4 but varies) above the stall speed to safely conduct say a 30 degree bank angle. Because of its laminar flow style wing profile, it wouldn't surprise me if it needed a significant cushion of airspeed to stay clear of the stall; knowing the harsh stall/spin characteristics that can develop.

Edited March 8, 2021 by Aurora_Stealth

[HawkerMkIII_]

1 hour ago, Aurora_Stealth said:

 

Just my five cents here...

 

160mph sounds too high to me to be its stall speed, but sounds a lot like the minimum maneuvering speed, which gives a large margin (typically x1.4 but varies) above the stall speed to safely conduct say a 30 degree turn. Because of its laminar flow style wing profile, it wouldn't surprise me if it needed a significant cushion of airspeed to stay clear of the stall; knowing the harsh stall/spin characteristics that can develop.

Yeah, it might honestly be just like a minimum maneuvering speed... airliners' stall speed is around 130 knots, there's no way a WW2 fighter will stall at that speed. 

[RedKestrel]

1 hour ago, jollyjack said:

To Flap or not to Flap ..... yesterday i tried a P38, with flaps about 30% it seems to turn tighter ..

The P-38 has flaps specifically for maneuvering though. Not all flaps (should) give you a benefit to turning performance.

[HawkerMkIII_]

2 minutes ago, RedKestrel said:

The P-38 has flaps specifically for maneuvering though. Not all flaps (should) give you a benefit to turning performance.

Yeah, I  think a good example of that is the P51D.

[ZachariasX]

3 hours ago, -332FG-Razor_ said:

Hello guys, on one of the book I'm reading about the Tempest, some specifications showed up and said minimum speed is 160 mph, Is it the stall speed? Maybe minimum recommended speed? Maybe minimum speed for proper flight/maneuvers? 

On the deck, the Tempest should be able to pull 2 g flaps up at 160 mph TAS asuming a Clmax of about 1.2 (Where it probably is.) before it stalls. Flaps down give you a lower speed.

 

It would be nice what the legend to that table says, the -1.

 

Generally, you have to be extremely careful with these tables. The PN give you INDICATED airspeed. At minimum speeds, this can be of like 20 mph from TAS, but what matters to the pilot then is not TAS but what is shown on his dial.

 

With a Clmax of 1.2, the Tempest at 5'600 kg flaps up stalls around 115 mph, flaps down and an assumed Clmax of 1.6, we get 100 mph, all TAS. 30 mph error on the dial is possible.

 

Keep in mind, many of those reference tables in books are copy and pasted together without sanity chacking the data, it is just trusting from where they copied, hence when these "sources" get mixed in further compilations of data, you get data.

[unreasonable]

3 hours ago, -332FG-Razor_ said:

Hello guys, on one of the book I'm reading about the Tempest, some specifications showed up and said minimum speed is 160 mph, Is it the stall speed? Maybe minimum recommended speed? Maybe minimum speed for proper flight/maneuvers? 
 

It's weird because the USAAF test said that it was 90mph with a clean configuration, but the other technical data says it's 160 with the flaps down, which I'm guessing it's from the RAF flight testing.

 

I think that 160mph may be taken from the section "55 Flying limitations" in the manual, which gives a list of speeds at which "the aircraft is designed".  Flaps down being listed as 160 mph IAS, which is the lowest number in that section. But it is certainly not a minimum speed, there are plenty of conditions in which the recommended speed is lower, so that source is not very reliable. 

Edited March 8, 2021 by unreasonable

[Mitthrawnuruodo]

Yes, we know for certain that the stall speed is much lower than 160 mph. It's only the speeds below 120 mph that are uncertain because we don't have airspeed indicator corrections. 

 

I don't think general books will be helpful as they typically rehash (or in this case misinterpret) basics from the Pilot's Notes. We need more esoteric information such as lift coefficients or calibrated stall speeds.

 

1 hour ago, ZachariasX said:

It would be nice what the legend to that table says, the -1.

 

Isn't the -1 simply "inverse hours" for a different way to write km/h?

 

4 hours ago, -332FG-Razor_ said:

It's weird because the USAAF test said that it was 90mph with a clean configuration, but the other technical data says it's 160 with the flaps down, which I'm guessing it's from the RAF flight testing.

 

The 90 mph result is plausible. It's very close to the 85 mph in the Pilot's Notes. However, it's still only an indicated speed, so it's not very useful. Our Tempest in Il-2 GB already has a higher value for its (calibrated) stall speed.

Edited March 8, 2021 by Mitthrawnuruodo

[ZachariasX]

39 minutes ago, Mitthrawnuruodo said:

Isn't the -1 simply "inverse hours" for a different way to write km/h?

Now that you say it, but how unusual. Doing the km h^-1 instead of km/h is formally correct I guess but I have never seen it. (At least that I can think of.)

[Panthera]

I think the reason the Tempest & Mustang comparison concluded the way it did in British testing, is that these tests IIRC generally were carried out at rather high altitude, where the Mustang has a clear advantage.

 

Down below 15,000 ft I don't see why the Tempest shouldn't outturn the Mustang sustained. That said IMHO they both turn too well ingame atm, but that's another discussion.

 

Both aircraft feature an airfoil with a small radius LE, and a max camber rather far back, so I don't see why the Mustang should have a noticable advantage in this area. Meanwhile the noticably lower wing loading of the Tempest would help reduce the induced drag for the same G's pulled, couple this with the higher power to weight below 15 kft and the Tempest should have an advantage in sustained turn performance.

 

As for istantanous rate, well we'd need to have a mach vs cl graph for both aircraft to really figure that out, but I don't see why the Mustang should have a noticable advantage here given the similar airfoil designs. 

 

Just my two cents.

Edited March 8, 2021 by Panthera

[JtD]

If you just go with wing area, weight, span and power, there's very little to chose between a P-51B V-1650 and a Tempest V Sabre IIb 11lb at lower altitudes. But the Sabre IIb at 11 lb is probably not what the comparison refers to, and with a Sabre IIa at 9 lb it's already is not that competetive anymore. This is before looking at aerodynamic qualties in more detail, which I think would shift the picture a little bit more in the P-51's favour, even if only a little.

[Mitthrawnuruodo]

3 hours ago, ZachariasX said:

Now that you say it, but how unusual. Doing the km h^-1 instead of km/h is formally correct I guess but I have never seen it. (At least that I can think of.)

 

Yes, it is a strange way to write it. Typically I only see the "^-1" notation in certain scientific literature. Don't recall ever seeing it in the case of km/h.

[Panthera]

56 minutes ago, JtD said:

If you just go with wing area, weight, span and power, there's very little to chose between a P-51B V-1650 and a Tempest V Sabre IIb 11lb at lower altitudes. But the Sabre IIb at 11 lb is probably not what the comparison refers to, and with a Sabre IIa at 9 lb it's already is not that competetive anymore. This is before looking at aerodynamic qualties in more detail, which I think would shift the picture a little bit more in the P-51's favour, even if only a little.

 

I was assuming the following specs:

 

Tempest V

2,200-2,420 hp 

5,170 kg weight

28.1 sq.m. wing area

_____________________

Wing loading: 183 kg/sq.m.

Power to weight: 0.42-0.47 hp/kg

 

P-51B

1,650-1,790 hp 

4,175 kg weight

21.8 sq.m.

_____________________

Wing loading: 192 kg/sq.m.

Power to weight:  0.39-0.43 hp/kg

 

 

A very simplistic comparison for sure, but I think it shows that below 15 kft the Tempest most likely had the higher sustained turn performance, whilst at higher altitude the Mustang probably had a slight advantage as noted in the english comparison. As for instantanous rate, like I said we would need a cl vs mach graph,  but the Tempest does have the initial advantage of a lower wing loading.

 

Either way I do agree that the Tempest is overperforming in terms of turn performance ingame,I just don't see the AFDU trials as a useful example to demonstrate it.

[JtD]

For sustained turn consider span loading. The square of it is equivalent to induced drag. The Tempest needs about 15% more power to sustain the same turn.

 

The power you're assuming might be representative for sea level, but at 10000ft the V1650-3 at 67" produced ~1700hp, the Sabre IIa at 9lb ~1800hp, IIb at 11lb about 2000hp. 10000ft is much more representative for altitudes below 15000ft than sea level figures are.

If you feel like using an power average 0-15000ft at typical turning speeds, you're around 1650 for the 1650 and at 1850/2100 depending on boost for the Sabre II. Power advantages for the Tempest therefore are 10-25% if you go with the averages and 5-15% if you go with 10000ft power. In practice it's only below 5000ft where the extra 500hp of the first gear of the Sabre give the Tempest the advantage.

[CSW_606_Temp]

One think. Mustang Wing had laminar profile. This profile was not good ať high AoA. Tempest had "half laminar" Wing profile and his profile was better for maneuvre at high AOA. Clasical profile on the Spit was the best.

 

Second think. We hav not concrete  inputs. Altidude? Engines? Fuel capacity? Speed? 

 

From RAF test between Spitfire And Tempest - below 300Mph Spitfire turn better. 300-400 turn equal, 400+ turn better Tempest. Tested 9lb vs Spitfire XIV 21lb.

Edited March 9, 2021 by CSW_606_Temp

[ZachariasX]

1 hour ago, CSW_606_Temp said:

Tempest had "half laminar" Wing profile and his profile was better for maneuvre at high AOA. Clasical profile on the Spit was the best.

The Tempest had a wing profile specially selected for low drag at high speeds. It has more like a "Jet" wing that is meant to go fast than for instance a Clark Y.

 

You can see here:

http://airfoiltools.com/airfoil/details?airfoil=tempest1-il

that the Tempests wing profile has the nose very high up, much higher than the Clark Y:

http://airfoiltools.com/airfoil/details?airfoil=clarkyh-il

You can see how "traditional" profiles can efficiently sustain higher AoA than the Tempests and how much that costs in terms of Clmax. How big they had to make the flaps on the Tempest is rather telling to compensate for this restriction in AoA and this lift. making a "low" nose for your profile acts like a slat and permits your profile to reach higher AoA. The price you pay for that is some drag at high speed. This is another secret of why the Tempest is a very fast aircraft. Not because it reaches high speeds (many aircraft of the time do) but because it can fly fast efficiently.

 

The same is the case with the Mustang. Although it has a "laminar" wing, it reaches higher AoA and gives more lift, especially at the base:

http://airfoiltools.com/airfoil/details?airfoil=p51droot-il

It is interesting that the Mustang has a very "fast" profile at the tip:

http://airfoiltools.com/airfoil/details?airfoil=p51dtip-il

where it hardly reaches a Clmax of 1. This is compensated by the wing twist of 2.25 degrees of washout that is applied in linear fashion.

 

This is probably the recipie for the Mustangs relatively benign slow flying qualities. The pilot retains full control down to speeds of ~100 mph indicated where the aircraft gets "mushy" and starts a progressively increasing yaw oscilation the slower you get, this to the degree where prop gyro forces actually bend the whole engine/gearing/propeller mounting such that the spinner touches the airframe and starts making a mess of it all. If it's your aircraft, you don't want it to do that.

 

Anybody knows the washout applied on the Tempest?

 

The Mustang is built with the same thing in mind as the Tempest, while being slightly more conservative at how far you take the concept. This also gives room for big wingtanks, but less so as in the P-38 where the wing is very fat at the root to host big tanks. Kelly didn't think it being an issue, no plane has ever gone fast enough to raise an issue.

 

 

[CSW_606_Temp]

Please open this chart with wings profil one more time and look better. Tempest profile is similar with YH Clark? What? ? 
Maybe is similiar Tempest and Mustang. But Mustang have turbulent part shorted because have laminar profile. Look at thicknes vs percent of the chord. Clark YH 30%, Tempest 38,5%, P-51 38,9%. 
Thicknes 13% is too low for good turning? Wow, Spitfire have the same thicknes 13%. I dont know about Spitfire bad turning because thick wing ? (Schneider Trophy Supermarine racer special had fast wing with 9,8% thicknes)
Tempest wing profile is between P-51 and Spitfire. So why is she wing bad for turning? 

BTW very similar profile with Tempest had late Spitfire version.
Rumors about thick Temepst wing is because comparisson with Typhoon fat wing (19%)

Edited March 9, 2021 by CSW_606_Temp

[HawkerMkIII_]

I’m not an expert on this or none of that (although I’m informing myself on it to try to understand this wing thickness thing), but I think that the reason why the Spitifre and Tempest turn so differently is that the Spitfire is considerable lighter and has a lower wing loading... even in flight testing it said they’re very different and that the Spitfire will out maneuver the Tempest, it is said the same for the Mustang III, which would resemble a P51B.

Edited March 9, 2021 by -332FG-Razor_

[ZachariasX]

6 minutes ago, CSW_606_Temp said:

Please open this chart with wings profil one more time and look better. Tempest profile is similar with YH Clark? What? ? 

Huh? I said that they are different and gave you both profiles to comare. The point was to show how the Thempest wing differed from a high lift wing (ClarkY). But at least you got that.

 

The Tempests wing is as "laminar" as the Mustangs. In the real world, they are not laminar, but they are lower drag profiles than the commonly found NACA-230XX-Serie profiles or the ClarkY.

 

9 minutes ago, CSW_606_Temp said:

Thicknes 13% is too low for good turning? Wow, Spitfire have the same thicknes 13%.

Who said that? The Spitfire has a higher lift profile than the Tempest AND lower wing loading. Very low actually and lottsa power. That is why it turns so well. And Why it needs almost no flaps to land. Look at the flaps size of the Tempest, then compare the Spitfires.

 

11 minutes ago, CSW_606_Temp said:

So why is she wing bad for turning? 

It's not bad for turning, but it does require more power to do so.

 

12 minutes ago, CSW_606_Temp said:

BTW very similar profile with Tempest had late Spitfire version.

You mean the Spiteful?

 

Anyway, I'll leave it at that.

[CSW_606_Temp]

Yes, wing loading is very important. And Tempest have lower wing loading, then FW 190 and late Bf 109. Good power/weight ratio. Wing profile is not problem. So it isnt reason for bad turning performance.

[Dr_Molem]

3 minutes ago, CSW_606_Temp said:

Yes, wing loading is very important. And Tempest have lower wing loading, then FW 190 and late Bf 109. Good power/weight ratio. Wing profile is not problem. So it isnt reason for bad turning performance.

 

Who talked about bad turning performance actually..?

[HawkerMkIII_]

4 hours ago, CSW_606_Temp said:

Yes, wing loading is very important. And Tempest have lower wing loading, then FW 190 and late Bf 109. Good power/weight ratio. Wing profile is not problem. So it isnt reason for bad turning performance.

We're not saying the Tempest should turn bad... it should turn worse than a P51D, but better than a P47. What we're saying is that RIGHT NOW it's turning too tight for what it should be... Looking from your name, it seems like you're a Tempest fanboy, I also am, it's my favorite plane! But sometimes you have to admit some things are wrong.

[Panthera]

On 3/10/2021 at 3:38 AM, -332FG-Razor_ said:

We're not saying the Tempest should turn bad... it should turn worse than a P51D, but better than a P47. What we're saying is that RIGHT NOW it's turning too tight for what it should be... Looking from your name, it seems like you're a Tempest fanboy, I also am, it's my favorite plane! But sometimes you have to admit some things are wrong.

 

I don't think it should turn worse than the P-51D, which is heavier than the P-51B and has the same power.  That said above 15 kft I'd say the P-51 probably generally had the advantage over the Tempest.

 

Edited March 14, 2021 by Panthera

[Panthera]

On 3/9/2021 at 6:53 AM, JtD said:

For sustained turn consider span loading. The square of it is equivalent to induced drag. The Tempest needs about 15% more power to sustain the same turn.

 

The power you're assuming might be representative for sea level, but at 10000ft the V1650-3 at 67" produced ~1700hp, the Sabre IIa at 9lb ~1800hp, IIb at 11lb about 2000hp. 10000ft is much more representative for altitudes below 15000ft than sea level figures are.

If you feel like using an power average 0-15000ft at typical turning speeds, you're around 1650 for the 1650 and at 1850/2100 depending on boost for the Sabre II. Power advantages for the Tempest therefore are 10-25% if you go with the averages and 5-15% if you go with 10000ft power. In practice it's only below 5000ft where the extra 500hp of the first gear of the Sabre give the Tempest the advantage.

 

Well unless I'm looking at the wrong engine power chart the difference in power was also usually over 15%, and as high as 35% at low altitude (below 5000 ft).  

 

Could it be you're looking at Sabre IIA power curves and not Sabre IIB ones? AFAIK the IIB gained a power boost over the IIA at all altitudes.

 

Also let's not forget that in games such as these most fights take place below 5,000 ft to begin with, and if not they usually end up there in the end.

Edited March 14, 2021 by Panthera