Jump to content

Hawker Tempest turning performance


Recommended Posts

Hello guys, I'd like to talk about the Hawker Tempest's turning performance on the simulator  - it literally out turns everything it faces, by a lot, and it shouldn't be like that. 

 

Here's some data I found about the Tempest turning circle.

 

As you can see, it compared the Tempest's turning circle similar to that of a P47, yet, in game, the Tempest out turns the Mustang, the P47, the 190's 109's, and everything that's on the way, at low speeds and at high speeds.

 

So yeah, just wanted to point that out and hope they fix this. Have a nice day, everyone!

 

~Razor.

Screenshot (549).png

Screenshot (548).png

Tempest vs P51 Screenshot (547).png

Tempest vs  Fw 190D9Screenshot (546).png

Also, I know on the first image it shows a Tempest II, but if you read closer it says II & V, so yeah, it does show the V.

 

The sources for the data I found are http://www.wwiiaircraftperformance.org/sl-wade.html  and http://www.wwiiaircraftperformance.org/tempest/tempestafdu.html

 

 

Edited by -332FG-Razor1
  • Thanks 1
  • Upvote 11
Link to post
Share on other sites

The crazy turning performances of Tempest always felt weird to me. But never tried to found real data yet. 

 

I just made some calculations with specs from the game.

 

109G14

Power (sea level MW50): 1800 hp

Minimum weight: 2899 kg

Wing surface: 16,1 m²

Power/weight ratio: 1,61 kg/hp

Weight/wing surface ratio: 180 kg/m2

Turn perf (270kph): 23 sec 

 

109K4

Power (sea level, MW50, DC engine): 2000 hp

Minimum weight: 3006 kg

Wing surface: 16,1 m²

Power/weight ratio: 1,5 kg/hp

Weight/wing surface ratio: 186 kg/m²

Turn perf (270kph): 24,2 sec

 

190D9

Power (sea level, MW50): 2130hp

Minimum weight: 3759kg

Wing surface: 18,3m²

Power/weight ratio: 1,76 kg/hp

Weight/wing surface ratio: 205 kg/m²

Turn perf (300kph): 20sec

 

Tempest

Power (sea level, emergency): 2180 hp

Minimum weight: 4585 kg

Wing surface: 27,8 m²

Power/weight ratio: 2,1 kg/hp

Weight/wing surface ratio: 165 kg/m²

Turn perf (270kph): 20sec

 

 

It confirms what we see in game: can turn better than its opponents but doesn't climb faster. 

But I guess that more parameters count...

Edited by JG300_Faucon
  • Like 1
  • Confused 1
  • Upvote 2
Link to post
Share on other sites

 

Thanks for your tests and for your reply. 

 

Yes, some parameters also count like pilot skill and energy states, and fuel quantity, but as you tested, in a flat turn it out turns everything at both low speeds and high speeds especially at low speeds where weight becomes more relevant, and with all I sent (saying the Tempest turned similar to a P47) I think it's enough proof on how it turned in real life, which is not correct in-game, especially for its size and weight. Thanks again for your reply. It really helps.

 

Edited by -332FG-Razor1
Link to post
Share on other sites
5 hours ago, JG300_Faucon said:

The crazy turning performances of Tempest always felt weird to me. But never tried to found real data yet. 

 

I just made some calculations with specs from the game.

 

 

 

It confirms what we see in game: can turn better than its opponents but doesn't climb faster. 

But I guess that more parameters count...

 

I think that a better comparison would be with the 109k4 with the db engine (the DC was an unicorn), the tempest at 11lbs (common by boddenplate) and at standar weight.

Other things to consider is that the turning performance given for the 109s are for combat pwr only. At emergency they are much much better.

Finally, I think that with those parameters and no other (like coeff of lift) the Tempest in pure sustained turnign should be worse than 109s but better than the D9. Perhaps the feeling that the Tempest turn better online comes from some instant turning contest (Tempest with its low wing loading and good elevator authority should reign there). In my experience, in pure sustained contests the 109s are better (or I am a worse pilot too).

 

Looking at all those figures I find something that a consider a bit odd regarding the p-47. If we compare it with the A8 both at a standar weight.

P-47D28

Power (sea level, emergency 64inches): 2600hp

Standard weight: 6503

Wing surface: 27.87m²

Power/weight ratio: 2.50 kg/hp

Weigth/wing surface ratio: 233,33 kg/m²

Turn perf at emergency pwr 64inch at sea level: 27,5 sec

 

Fw190A8

Power (sea level, emergency): 1700hp

Standard weight: 4391

Wing surface: 18,37m²

Power/weight ratio: kg/hp: 2,58

Weigth/wing surface ratio: 239 kg/m²

Turn perf at emergency pwr at sea level: 24,2sec

 

Leaving other parameters aside, just in pure wing and power loading the p-47 seems better and yet in the game, according to the devs is quite worse (by 3 secs).


 

 

Link to post
Share on other sites

A little bit of flap on the Tempest in-game in the turn is a great help.  8 to 10 deg.

 

Very easy to black out in-game in the turn in a Tempest. 

 

Tempest is very slow in-game to accelerate after speed loss.

 

Flat turns are not a good idea and not good dogfight manoeuvring tactics.  Tactical egg is better.

https://commons.wikimedia.org/wiki/File:Fighter_maneuvering_-_tactical_egg.PNG

Link to post
Share on other sites

I've not been paying much attention to these forums lately, but has anyone done an investigation on the max achievable lift coefficient in-game, flying the Tempest?  Asking because if the game is simulating lift based on a modified vortex panel model, then sections of the wing bathed in prop wash might be seeing an unrealistically high lift coefficient which might account for the superb turn performance being observed.

Link to post
Share on other sites

I dont't undestand how this isn't talked about more.

 

There is not a single performance documentation that would support the idea that the Tempest in-game performs close to it's real life counterpart.

In fact, every single piece of documentation available claims the opposite.

 

What's even funnier is that it overperforms like crazy, but then they didn't give it enough ammunition per gun for some reason. 

Truly a gem.

Edited by ACG_Onebad
  • Upvote 2
Link to post
Share on other sites
2 hours ago, ACG_Onebad said:

What's even funnier is that it overperforms like crazy, but then they didn't give it enough ammunition per gun for some reason. 

 

That is entirely wrong about the ammo count - every ammo expenditure report for Tempest squadrons shows they loaded the cannons with 150 rounds max. 

 

And no, Clostermann is not a reliable source on this subject. 

  • Upvote 2
Link to post
Share on other sites

How can I make the developers notice this topic? I think it deserves serious attention.

3 hours ago, ACG_Onebad said:

I dont't undestand how this isn't talked about more.

 

 

Because Tempest pilots (myself included) are too comfortable with this broken turning performance to discuss it. 

  • Haha 4
  • Upvote 1
Link to post
Share on other sites
1 hour ago, -332FG-Razor1 said:

How can I make the developers notice this topic? I think it deserves serious attention.

Because Tempest pilots (myself included) are too comfortable with this broken turning performance to discuss it. 

 

...and the rest of us are tired of being called whinners! :coffee:

I have been saying since for awhile, the current FM gives too much value to something, not sure if it's wing load maybe?

That would make sense since I have seen plane dogfight that shouldn't, a la B-25s and the Il-2s.

Edited by JG7_X-Man
  • Thanks 1
  • Upvote 2
Link to post
Share on other sites
4 hours ago, LukeFF said:

And no, Clostermann is not a reliable source on this subject. 

 

I have to agree on Clostermann - I don't think he's a reliable source on anything really. 

If it's true that literally every single period source shows that it only carried 200 RPG in theater then so be it, I'm going going to go through every single AAR to debate that (yet! 😄 )

Ammo aside, I'd like to see the devs give the Tempest a second look. I think even it's fans (myself included) have noticed that something ain't right with it's flight characteristics and nobody is going to be mad if a more realistic Tempest means a worse performing Tempest. 

 

  • Like 1
Link to post
Share on other sites
On 11/6/2020 at 7:27 AM, HR_Zunzun said:

 

I think that a better comparison would be with the 109k4 with the db engine (the DC was an unicorn), the tempest at 11lbs (common by boddenplate) and at standar weight.

Other things to consider is that the turning performance given for the 109s are for combat pwr only. At emergency they are much much better.

Finally, I think that with those parameters and no other (like coeff of lift) the Tempest in pure sustained turnign should be worse than 109s but better than the D9. Perhaps the feeling that the Tempest turn better online comes from some instant turning contest (Tempest with its low wing loading and good elevator authority should reign there). In my experience, in pure sustained contests the 109s are better (or I am a worse pilot too).

 

Looking at all those figures I find something that a consider a bit odd regarding the p-47. If we compare it with the A8 both at a standar weight.

P-47D28

Power (sea level, emergency 64inches): 2600hp

Standard weight: 6503

Wing surface: 27.87m²

Power/weight ratio: 2.50 kg/hp

Weigth/wing surface ratio: 233,33 kg/m²

Turn perf at emergency pwr 64inch at sea level: 27,5 sec

 

Fw190A8

Power (sea level, emergency): 1700hp

Standard weight: 4391

Wing surface: 18,37m²

Power/weight ratio: kg/hp: 2,58

Weigth/wing surface ratio: 239 kg/m²

Turn perf at emergency pwr at sea level: 24,2sec

 

Leaving other parameters aside, just in pure wing and power loading the p-47 seems better and yet in the game, according to the devs is quite worse (by 3 secs).


 

 

Not trying to highjack the thread but I've noticed this as well. I've always read the P-47 and A8 were near equals in turn performance at med-low altitudes (not exact but very close) I've even seen guncamera of a A8 shooting at a P-47 and the A8 was struggling to get any lead on the P-47. The A8  would start to buffet and stall when pulling lead, they were nearly identical in turn. I go into more detail on the P-47 thread, I don't want to take away from this thread.

 

I do agree though that the Tempest needs adjustment and should be closer in line to the A8/P-47. I was very surprised when I first flew the Tempest in-game. I was expecting it to be similar to the P-47 in flight characteristics (average turn, good dive, and good zoom) I wasn't expecting it to be spitfire in disguise. Turn feels wrong in-game based off of everything I've read about the tempest (not much to be honest but still)

Edited by Legioneod
Link to post
Share on other sites
1 hour ago, ACG_Onebad said:

 I think even it's fans (myself included) have noticed that something ain't right with it's flight characteristics and nobody is going to be mad if a more realistic Tempest means a worse performing Tempest. 

 

Same here. The Tempest is my favorite plane, since I knew about it in War Thunder XD. I’d rather see a worse performing Tempest than a broken one.

Link to post
Share on other sites

Я поэтому и стараюсь не садиться на него. Сейчас это лучший истребитель в игре. У машины с массой 5,5 тонн вираж как у Е7, а то и лучше. У него нет недостатков, кроме сильных воздействий перегрузок на лётчика. Я тоже сомневаюсь в правильности его реализации. Но вот ролл у него точно должен быть неплох. 

 

That's why I try not to sit on it. Now it is the best fighter in the game. The car with a mass of 5.5 tons turns like the E7, or even better. It has no drawbacks, except for the strong effects of overloads on the pilot. I also doubt the correctness of its implementation. But the role he definitely should be good.

 

 

Inspect_cockpit.jpg

  • Confused 1
Link to post
Share on other sites

I think that the low speed turning could be the problem although I would like to see actual test of turning to give a better opinion.

What has to be taken into account is that the wing loading of the tempest is really good (it has huge wings). And although not in the same league as the spit, its wing loading is clearly better than the rest of the fighters is has been compared to here (D9, Me109G14 and K4, Jug and A8). With speed and her good elevator authority, I don't see why it shouldn't turn better than all of them (bar the spit). G loading is very limiting there (although has improved with the last patch).

Once it hit the sustained turning realm my feeling is that it should get behind me109, slightly better than the D9 and still better than Jug or A8 (That's why a sustained turn test is needed).

3 hours ago, Legioneod said:

Not trying to highjack the thread but I've noticed this as well. I've always read the P-47 and A8 were near equals in turn performance at med-low altitudes (not exact but very close) I've even seen guncamera of a A8 shooting at a P-47 and the A8 was struggling to get any lead on the P-47. The A8  would start to buffet and stall when pulling lead, they were nearly identical in turn. I go into more detail on the P-47 thread, I don't want to take away from this thread.

 

Yes, it would need its own thread. Sorry to raise this here.

Link to post
Share on other sites

Be aware that the Tempest has been adjusted before. In Update 4.001, the stall speed was increased by 6 mph (maximum lift coefficient was reduced). To me this suggests that problems with the FM are not trivial to identify or solve.

 

1 hour ago, ACG_Onebad said:

Also besides the turn, the stall speed is very low and the slow speed lift/characteristics are also unusually good for an aircraft with a laminar flow wing which by design is great at high speed and bad at slow speed. 

 

According to the Pilot's Notes for the Tempest V with Sabre IIA, the stall speed in clean configuration at 11,500 lb. is 85 mph, but we don't know the position error of the airspeed indication because the speed is beyond the range of the correction table. Extrapolating the data with the assumption that the relationship is linear, we get an error of 5.5 at 85 mph, giving a corrected stall speed of 90.5 mph. This is below the lowest listed in-game clean stall speed of 150 kph.

 

That leaves us with a tricky situation. How should we interpret these results? What could be changed without conflicting with the published figures?

Link to post
Share on other sites
Just now, Mitthrawnuruodo said:

Be aware that the Tempest has been adjusted before. In Update 4.001, the stall speed was increased by 6 mph (maximum lift coefficient was reduced). To me this suggests that problems with the FM are not trivial to identify or solve.

 

 

According to the Pilot's Notes for the Tempest V with Sabre IIA, the stall speed in clean configuration at 11,500 lb. is 85 mph, but we don't know the position error of the airspeed indication because the speed is beyond the range of the correction table. Extrapolating the data with the assumption that the relationship is linear, we get an error of 5.5 at 85 mph, giving a corrected stall speed of 90.5 mph. This is below the lowest listed in-game clean stall speed of 150 kph.

 

That leaves us with a tricky situation. How should we interpret these results? What could be changed without conflicting with the published figures?

 

The tech specs for the Tempest give a range of weights and range of clean stall speeds. The most sensible comparison is to use the Maximum take off weight with the highest speed, and the minimum operational weight with lowest speed.

 

If you do this with the current tech spec speeds of 150-175 kph and 4585-6190 kg, you get a Cl max of 1.526 and 1.521   This is higher than for any other single seat fighter: for example the 109s are ~1.40, Spitfires ~1.33

 

This is after the stall speeds were increased - I asked in the launch thread why the first Tempest release had a Clmax of over 1.70! Actually I knew the answer: they had tried to fit the wing to the manual's stated stall speeds rather than fit the game's stall speeds to the wing, contrary to their practise in every previous plane issue, which took into account that we do not have IAS in the game: we have CAS: as you say there is no PEC.  There is no reason in principle why the Tempest wing should have such a high Clmax: at least no-one has yet given one.

 

1426668091_Tempestoldandnew.thumb.JPG.abd9ef67f104efadcb22239f8c73f9cc.JPG

 

The problem is that linear extrapolation of PECs from manuals may significantly underestimate the error at high AoA. By comparison, RAE tests on a 109 done with a trailing pitot demonstrated errors of ~20 mph at close to stall speeds. Not the same plane, etc, but it shows what can happen: normal PECs are used to calculate speeds for navigation purposes, so they would not normally be relevant to pilots while close to stall speed.

 

177331979_109snip3.PNG.adb1b6c2960094c839ac6c5647daac59.PNG

 

IMHO it would be better to rejig the Tempest's FM to give it a Cl max roughly equivalent to the Spitfire or P-51 and suck up the fact that this will lead to significantly higher stall speeds and make the manuals even more useless. It might also reduce the sudden black out problems by reducing the lift generated per degree of AoA change.

 

(Even better, introduce PECs as well but that would be another whole module of work). 

 


 

  • Thanks 3
  • Upvote 2
Link to post
Share on other sites
2 hours ago, unreasonable said:

IMHO it would be better to rejig the Tempest's FM to give it a Cl max roughly equivalent to the Spitfire or P-51 and suck up the fact that this will lead to significantly higher stall speeds and make the manuals even more useless. It might also reduce the sudden black out problems by reducing the lift generated per degree of AoA change.

 

Whatever tweak needed to give it the turning radius of the P-47.

Link to post
Share on other sites

I do not actually know how much changing the Clmax would change turn radius: I assume it would do so in some circumstances but not all. It clearly is not the only determinant, since the Spitfires have lower CLmax than the 109s but are "scored" with a tighter turn in the illustration. P-47s also have a higher wing loading than Tempests, unless you compare an empty P-47 with a fully bombed up Tempest, so I am not sure they would be identical, but maybe much more similar than currently in the game.

 

But I am happy to leave those trade-offs to the aerodynamic experts. I just know how to fill in a spreadsheet: not something I am particularly proud of, but you have to play the cards you are dealt.  :( 

  • Upvote 1
Link to post
Share on other sites

Did a quick test.

CLEARLY my methodology is open to some inaccuracies, but I'd thought I'd do a down and dirty rough comparison, so thank you in advance for not pointing that out.

All planes were default loadout, with 400l fuel.
Left hand circle. Full power.
Attempted to do max performance turn and used the marks on the runway to judge radius.image.thumb.png.c7b45a599eb605b1ad660268f375c54f.png

 

Also this was in the 109 turn rate thread I think image.thumb.png.02ac189d5df78bc3c7575ade18d29fc7.png

  • Upvote 7
Link to post
Share on other sites
On 11/11/2020 at 11:31 AM, Barnacles said:

Did a quick test.

CLEARLY my methodology is open to some inaccuracies, but I'd thought I'd do a down and dirty rough comparison, so thank you in advance for not pointing that out.

All planes were default loadout, with 400l fuel.
Left hand circle. Full power.
Attempted to do max performance turn and used the marks on the runway to judge radius.image.thumb.png.c7b45a599eb605b1ad660268f375c54f.png

 

Also this was in the 109 turn rate thread I think image.thumb.png.02ac189d5df78bc3c7575ade18d29fc7.png

What do you mean by Max performance turn? Pull back on the stick as much as possible before stalling or you went for the max sustained turn rate?

Something that a lot of us have a tendency to forget is that the numbers on the stat cards in game are max sustained turn rate. So you enter the turn at the listed speed, at the listed power and this is the amount of time you need to complete a 360. When we fight, most of us don't do sustained turn! We just trade a lot of energy for instantaneous turn rate and bleed energy in the process. The tempest, like the Spitfire, are amazing at doing that since they retain almost all their elevator authority at high speed.

Radius of turn doesn't have much to do with rate of turn. A plane with a much larger turn radius could have a better turn rate hence finishing a 360 deg turn before a plane with smaller radius.

 

As for the turn rate, this is very interesting. I just find it weird that all plane were tested at the same speed. I was under the impression that all airframe should have a slightly different max sustained turn rate. If they do have a different max sustained turn rate, the data there are erroneous since they were all tested at the same speed. 

Link to post
Share on other sites
1 hour ago, =X51=vaudoo said:

 

 

As for the turn rate, this is very interesting. I just find it weird that all plane were tested at the same speed. I was under the impression that all airframe should have a slightly different max sustained turn rate. If they do have a different max sustained turn rate, the data there are erroneous since they were all tested at the same speed. 

I didn't make that turn rate chart, so I can't remember the reasoning behind doing them at the same speeds.

 

Link to post
Share on other sites
4 hours ago, Barnacles said:

I didn't make that turn rate chart, so I can't remember the reasoning behind doing them at the same speeds.

 

 

I'm not sure either. One must compare the p_0 curve for all airspeeds - not at a single point. 

 

It doesn't surprise me that the tempest has quite good sustained turning performance. At least down low. With 11 lb of boost, making 2400+ hp at sea level, gives it a pretty hefty .212 hp / lb. 

 

Compare that to: 
Spit mkIX - 0.235 hp / lb 

P51D - 0.187 hp / lb

Bf109G6 - 0.2165 hp / lb

 

These are "roughly" in line with the circles that @Barnacles posted. Of course, power/weight isn't the only factor. Total available lift, lift/drag ratio, prop efficiency, play an arguably equally important role as well. 

 

On another more productive note, consider the following paragraph from this NACA ACR report on the Spitfire Va: 

https://digital.library.unt.edu/ark:/67531/metadc61033/m2/1/high_res_d/19930092581.pdf

 

image.thumb.png.a31f99aa52c478e8630558ed59dcba2d.png

Notice that the Clmax in maneuvering flight is 1.22. 

 

Now compare this to the Clmax in cruising flight: 1.68. 

 

image.png.ed08742f6c48c88ef3650cfa373bcfcc.png

 

As mentioned in the paragraph boxed in red above, the CLmax during maneuvering is actually almost that of the power off Cl.   It seems that with the Spitfire specifically, the stall warning buffet designed into the wing lowers the total available lift. Furthermore, prop wash seems to have a diminished effect on available lift during hard maneuvers. 

 

So, at a glance, it seems that maneuvering coefficients should likely resemble the power off coefficients - in other words, the prop wash effects (which for the Tempest is likely enormous) should not have such an effect on the maneuvering capabilities of the aircraft. This might explain why the tempest could be over performing.

 

This might be the test one needs to do: Figure out what the Tempest's power off lift coefficient is and then compare it to the lift coefficient in a sustained max performance turn.  If there is a huge discrepancy, maybe we have a lead.

  • Upvote 3
Link to post
Share on other sites
On 11/17/2020 at 2:15 PM, =X51=vaudoo said:

What do you mean by Max performance turn? Pull back on the stick as much as possible before stalling or you went for the max sustained turn rate?

Something that a lot of us have a tendency to forget is that the numbers on the stat cards in game are max sustained turn rate. So you enter the turn at the listed speed, at the listed power and this is the amount of time you need to complete a 360. When we fight, most of us don't do sustained turn! We just trade a lot of energy for instantaneous turn rate and bleed energy in the process. The tempest, like the Spitfire, are amazing at doing that since they retain almost all their elevator authority at high speed.

Radius of turn doesn't have much to do with rate of turn. A plane with a much larger turn radius could have a better turn rate hence finishing a 360 deg turn before a plane with smaller radius.

 

As for the turn rate, this is very interesting. I just find it weird that all plane were tested at the same speed. I was under the impression that all airframe should have a slightly different max sustained turn rate. If they do have a different max sustained turn rate, the data there are erroneous since they were all tested at the same speed. 

 

Just to shine some light on what those listed turn times are that @Barnacles shared, and their original context... that earlier thread was investigating why at the Bf 109 G / K's best sustained turning speed (maintaining that set speed throughout and at constant altitude) - that an aircraft optimised for much higher speeds such as the P-51 (D-15) using a high speed optimised "laminar flow" wing, with a higher weight, inferior power-to-weight ratio, lacking high lift devices and inferior in lift production at low speeds; was still able to out turn the Bf 109 G / K at those low speeds where you would expect the opposite to happen.

 

Those specific tests were run at the same airspeed, all while using full emergency power (WEP) to collect data for a specific analysis/model that had been requested, the tests themselves proved a hypothesis that in-game a Bf 109 G-14 or K-4 that is pulling a sustained turn at its most optimal speed; is still out turned by the P-51 D (assuming all other characteristics including fuel weight being equal). And so at 75" boost and 400 litres, that was proven the case in-game. I'm not going to comment further - and yes agreed real air combat is practically never that linear or at all equal - but it proved a point.

 

So yeah please don't generalise or extrapolate that data out too far - as you correctly assert @=X51=vaudoo each aircraft has its own sweet spot speed which it best manoeuvres / turns and that comes down to design factors... that optimal speed for each aircraft is given in the IL-2 specs.

 

Regarding the Tempest, well... it doesn't show it in that listed test data we did for the reasons I've just mentioned... but frankly no data was felt needed at the time to prove that it was behaving outside of its real life operating characteristics - it flies as if it has an almost viceless flight envelope. @unreasonable mentioned this to us several months back on that '109 thread which made a lot of sense to me considering my strange encounters with them in-game especially online; he's been sharing his concerns and findings on CLmax for some time...

 

I'm relieved some people have created and are discussing this topic really, as I didn't want to be the one to shake the boat again following that '109 thread; only to get put down for saying what really should and I think is quite obvious now... to many in the community who have had time to compare it alongside the others.

 

It's become such an elephant in the room that not only do I think the Tempest put's all the opposition in a bad light (lol), it puts practically all of the other Allied fighters under its shadow as well and that's just going too far on enthusiasm - it was very good in its role as a specialised strike / low altitude interceptor but er... you certainly don't get the impression that it weighed the two tons more than a Spitfire from what you see in-game.

 

19 hours ago, Floppy_Sock said:

As mentioned in the paragraph boxed in red above, the CLmax during maneuvering is actually almost that of the power off Cl.   It seems that with the Spitfire specifically, the stall warning buffet designed into the wing lowers the total available lift. Furthermore, prop wash seems to have a diminished effect on available lift during hard maneuvers. 

 

So, at a glance, it seems that maneuvering coefficients should likely resemble the power off coefficients - in other words, the prop wash effects (which for the Tempest is likely enormous) should not have such an effect on the maneuvering capabilities of the aircraft. This might explain why the tempest could be over performing.

 

This might be the test one needs to do: Figure out what the Tempest's power off lift coefficient is and then compare it to the lift coefficient in a sustained max performance turn.  If there is a huge discrepancy, maybe we have a lead.

 

That's a really interesting point, I hadn't looked at it that way. Would be good if we could quantify it for sure.

Edited by Aurora_Stealth
  • Upvote 2
Link to post
Share on other sites

I'm not a flight engineer or an expert in aerodynamics, or even all that knowledgeable (compared to many here) on WWII aircraft.

That being said, for me the issue is that I'm not sure why, from the numbers that we have, the Tempest wouldn't be a good turning aircraft, or why we would expect it to have a similar turn performance to the P-47 (like we see in the diagram). From what I can tell the numbers from the game's specifications in terms of aircraft weight, horsepower available, wing area, etc. are accurate to the historical plane itself, or at least not completely out to lunch.

So the wing loading and the power to weight ratio should be accurate, and relative to many of the other planes in the sim (as per Black-Hawk's post above) it has a lower wing loading and its pretty close in power/weight ratio to many of its opponents. Broadly speaking that should make it a decently turning aircraft, right?

 

I'm not saying the Tempest doesn't currently turn too well - I think it does - but I guess I don't see how even if the game is very wrong that the Tempest goes all the way from Spitfire-turning capability to the same as the Jug, going by the numbers we have available. 

 

 

Link to post
Share on other sites

Show me the CL/CD charts for the airfoil at an appropriate reynold's number. Then maybe show me some CFD analysis to try to get the overall drag at the appropriate angle of attack. Then give me a detailed estimate of the propeller efficiency and thrust under those conditions...

Link to post
Share on other sites
2 hours ago, RedKestrel said:

I'm not saying the Tempest doesn't currently turn too well - I think it does - but I guess I don't see how even if the game is very wrong that the Tempest goes all the way from Spitfire-turning capability to the same as the Jug, going by the numbers we have available. 

Everyone seems to sink their teeth into wing loading, CLmax, and power-to-weight ratios. Perhaps we should have a closer look at trim drag during max performance and best sustained turns. If we were to compare two planes with identical wing loading, the one with less trim drag (i.e. the one with the center of gravity further back in relation to the center of lift) will be the better turner. That's why modern fighters have relaxed subsonic pitch stability. I've seen and documented many EF2000, Rafale, and F-16 displays, and I've never seen any significant control surface deflection to maintain high performance turns at / near corner speed. We know that the 190 series was quite neutral in pitch. Are there hints on the tempest trim drag in the literature?

Another important thing to consider is the air foil. Here, I'd expect the P-51 and Tempest to deliver less lift per square meter of wing than planes with thicker air foils.

Link to post
Share on other sites
5 hours ago, Avimimus said:

Show me the CL/CD charts for the airfoil at an appropriate reynold's number. Then maybe show me some CFD analysis to try to get the overall drag at the appropriate angle of attack. Then give me a detailed estimate of the propeller efficiency and thrust under those conditions...

 

The same can be said for everyone making claims here, doesn´t it?

Edited by HR_Zunzun
Link to post
Share on other sites
6 hours ago, JG27_PapaFly said:

Everyone seems to sink their teeth into wing loading, CLmax, and power-to-weight ratios. Perhaps we should have a closer look at trim drag during max performance and best sustained turns. If we were to compare two planes with identical wing loading, the one with less trim drag (i.e. the one with the center of gravity further back in relation to the center of lift) will be the better turner. That's why modern fighters have relaxed subsonic pitch stability. I've seen and documented many EF2000, Rafale, and F-16 displays, and I've never seen any significant control surface deflection to maintain high performance turns at / near corner speed. We know that the 190 series was quite neutral in pitch. Are there hints on the tempest trim drag in the literature?

Another important thing to consider is the air foil. Here, I'd expect the P-51 and Tempest to deliver less lift per square meter of wing than planes with thicker air foils.

 

We tend to look at the things that are easy to quantify accurately.  The Tempest V manual has quite a lot to say about using the trim, but what conclusions you can draw I am unsure:

 

1817420001_TempestVsnip1.thumb.JPG.297a21d07da96eabb6c3142f987ad090.JPGTempest V snip 2.JPG

 

7 hours ago, Avimimus said:

Show me the CL/CD charts for the airfoil at an appropriate reynold's number. Then maybe show me some CFD analysis to try to get the overall drag at the appropriate angle of attack. Then give me a detailed estimate of the propeller efficiency and thrust under those conditions...

 

The problem is that in order to get a whole plane measured CLmax equal to the GB version (initial or current) you would need to have airfoil CLs exceeding anything in the databases. There was nothing revolutionary about the Tempest wing. The current FM is still almost certainly wrong: the initial release was plain bonkers.  

 

There is a "Tempest" airfoil here: it is not a high lift airfoil.

 

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

 

 

Edited by unreasonable
  • Like 2
Link to post
Share on other sites
4 hours ago, HR_Zunzun said:

The same can be said for everyone making claims here, doesn´t it?

 

Yup :) I was talking to everyone... except maybe the devs... although, you know... I'd still kindof love to see their data!

  • Upvote 1
Link to post
Share on other sites

Turning performance Tempest V vs Typhoon from 1943 (+7lbs boost available at this time).

 

Source:

http://www.wwiiaircraftperformance.org/tempest/Tempest-V_Eng-47-1658-C.pdf

 

827432839_TempestTurnvsTyphoon.thumb.PNG.8a1a5c14c0292e0ca35c364823d09ac2.PNG

 

 

 

Two more things:

 

- asking @LukeFF: Where did you find that the Tempest only carried 150rpg? All my sources (well, those sighted so far) only give the capacity of 200rpg, but no additional information about combat loadouts. Would an additional, optional incresed 200rpg loadout make sense?

 

- paging all the others, too (certaily including @Talon_ ) : Would a +13lbs option make sense for the Tempest on the Normandy map, given that most (all?) Tempest units were supposed to go V-1 hunting? Can't find any evidence for or against the use of the +13lbs setting during that timeframe.

Link to post
Share on other sites
43 minutes ago, Bremspropeller said:

asking @LukeFF: Where did you find that the Tempest only carried 150rpg? All my sources (well, those sighted so far) only give the capacity of 200rpg, but no additional information about combat loadouts. Would an additional, optional incresed 200rpg loadout make sense?

 

I posted some of the ammo expenditure reports in the linked topic. Note that I initially misinterpreted the numbers, but upon looking at them further they agree with the ammo count currently in the game:

 

 

  • Thanks 1
Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...