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P-40 turn rate/Flight model check

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Does anyone have a source for typical oil pressure that the engine should indicate? Also looking for information to evaluate radiator efficiency.

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Sources for oil pressure are floating around, they vary slightly, but typical table for oil pressure can be seen for example here -

 

P-40E_Operation_Instructions.jpg

 

In the game, oil pressure is normaly at 100 psi and even around 110 psi on Military power +, at idle at 70 psi. When I use the range listed in different sources - it should be normaly at 60-75 psi, 15 psi at idle and maximum should be 85 psi.

Fuel pressure is in game at 16 psi all the time, at idle should be at 9 - 10 psi (depending on source).

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As for radiator efficiency - I'm sure that you have somewhere Boscombe Down report 783 (part 12) " Engine cooling trials", which is best source around for this. You even posted link to this report some time ago, so you must have it.

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It should also vary with oil temperature.

It doesn't? I never checked as always start with pre warmed engine. I mean it would be a central point why you have an oil temp gauge.

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anecdotes all have their use, but not in defining combat performance, unless every one available is taken into account, backed up with known and accepted performance figures

 
Cheers Dakpilot

 

 

Yeah I think that's the thing people need to remember right there.

 

Take for instance BoB, you have many German 109 pilot claiming they could outturn the Spitfire no problem and vice versa. 

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Also come to think of it maybe the developers are also taking into effect the extra lift provided by the accelerated airstream (propwash) from the propeller over the inboard wing section, an effect which is really taken advantage of on wings with outboard mounted slats as this prevents the outboard section from stalling before the inboard section which is energized by the propwash, thus increasing the overall CLmax by quite a margin when the aircraft is under power. This would explain why modern pilots claim the 109 is only slightly less capable in turns than a Spitfire. Those slats really do wonders when the inboard section is energized by propwash.

 

On jets you ofcourse you don't get this effect, and thus jets needed full span slats to gain the same benefits, Me262, F-86 and onwards.

Edited by Panthera

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Interesting to note, regarding P-40E clmax, here is  chart of "idling engine" clmax for the P39D:

 

 

post-16698-0-27415600-1518295380_thumb.jpg

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Question: Is the turn performance of the plane subpar overall when compared to german planes (which doesn't match anecdotal accounts) due to an incorrect issue with the FM, or due to the engine settings, or both? 

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Interesting to note, regarding P-40E clmax, here is  chart of "idling engine" clmax for the P39D:

 

Interesting but reproduction a little fuzzy: can you confirm that the numbers on the line for Gliding/Up/Up/Engine idling are 108mph / 1.35?

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Question: Is the turn performance of the plane subpar overall when compared to german planes (which doesn't match anecdotal accounts) due to an incorrect issue with the FM, or due to the engine settings, or both? 

 

You have missed out a possibility: that the anecdotes do not match reality.  For instance, P-40 pilots who tried to turn with German planes and failed are far less likely to survive to tell anecdotes about their comparative turning performance.

 

This is called survivor bias. So back in the German pilots' mess, there is a successful pilot talking about how he turned inside a P-40.

 

Hence the developers correct emphasis on measurable performance.

 

I fear that you are going to be even more unhappy if the developers manage to fix the measurable and acknowledged issue with 109 turn times being too low  [edit: too high! Sunday.] 

Edited by unreasonable

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After fighting better turning Hurricanes and Spitfires over the Channel, why would it even bother the German pilots if P-40's were also better turning? 

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You have missed out a possibility: that the anecdotes do not match reality.  For instance, P-40 pilots who tried to turn with German planes and failed are far less likely to survive to tell anecdotes about their comparative turning performance.

 

This is called survivor bias. So back in the German pilots' mess, there is a successful pilot talking about how he turned inside a P-40.

 

Hence the developers correct emphasis on measurable performance.

 

I fear that you are going to be even more unhappy if the developers manage to fix the measurable and acknowledged issue with 109 turn times being too low  [edit: too high! Sunday.] 

 

All first hand accounts I have read, which include that of a German pilot flying F4s in North Africa against P40Es, are consistent in this regard. The P40 easily out-turned 109s. The German pilots almost always stuck to diving through the circling P40s (RAF tactics of the day called for a defensive circle). According to all accounts, 109s that abandoned their advantage and turned with the P40s were quickly outturned. 

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All first hand accounts I have read, which include that of a German pilot flying F4s in North Africa against P40Es, are consistent in this regard. The P40 easily out-turned 109s. The German pilots almost always stuck to diving through the circling P40s (RAF tactics of the day called for a defensive circle). According to all accounts, 109s that abandoned their advantage and turned with the P40s were quickly outturned. 

 

Except for Marseilles, who dived into the middle of Luffberries and turned to shoot people down.  Most people do what they are used to. German pilots generally used diving attacks and not prolonged turn fights against everyone, so most of them would not have been very good at turn-fighting. That proves nothing about the technical capabilities of the aircraft.

 

You cannot draw clear conclusions about technical capabilities from tactical use. Too many other variables. 

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Regarding quotes, don't forget about Erwin Leykauf's testimony that he had no problems outturning Spitfires in his Me-109: He said it just had to be done right. So does that mean we can now conclude that the Me-109 turns better than the Spitfire?

 

Also, one of the other German aces (was it Steinhoff?) said that a lot of inexperienced German pilots thought they were pulling really tight turns and they had not yet even opened the slats but for him manouvering in earnest only began when the slats were out. Now what kind of conclusion about a Me-109's turn capability would an Allied pilot who came up against such an inexperienced "no slats out" German pilot draw? What would he tell his mates in the mess after pulling tighter and shooting down said German?

 

Regarding the P-40E outturning Me-109's I'm sure it was done against the no slats type of pilot and in addition, if the P-40E overboosted his engine temporarily then the extra power would do wonders for the turn rate as attached picture shows.

 

post-23617-0-86199200-1518353285_thumb.gif

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Or perhaps the engagement might have started at moderate to high speed, and the P-40 made the most of his superior initial turn rate and firepower to secure the kill before he ran out of excess energy and was left with the inferior sustained turn rate shown there in your table?

 

Supposing they started head on then I don't see that happening, but if the P-40 managed to sneak up on the 109's tail then the lighter elevator forces at high speed could help the P-40 pilot get in a quick deflection shot incase the 109 pilot tried to evade by turning.

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Interesting but reproduction a little fuzzy: can you confirm that the numbers on the line for Gliding/Up/Up/Engine idling are 108mph / 1.35?

I like the line below it. Gear down, flaps up, engine idling. No doubt the CLmax should be lower in this condition, than when gear UP and flaps up. :)

I think the gear down, flaps up, engine idling line shows CLmax of 1.55? :)

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Don't know why this "obsession" about "turning rates" persists? You only need to pull to get the final deflection angle before opening fire - this is what the instantaneous turn rate is for. Continuous turning is not healthy even if you are driving a Spit - there are better alternatives like yoyos.

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I like the line below it. Gear down, flaps up, engine idling. No doubt the CLmax should be lower in this condition, than when gear UP and flaps up. :)

I think the gear down, flaps up, engine idling line shows CLmax of 1.55? :)

 

I think it is 1.55 on that line too: unfortunately the only fuzzy line is the one above.

 

For the gliding up/up line my my best guess is it says 1.35, and it looks like 108mph, ie higher stall speed than with gear down, this is consistent with the CLmax being lower than in the last line.....I know that flaps dramatically increase CLmax but I have not thought about the effect of gear on it's own so I have no idea what the relationship should be.

 

I will stick my neck out and predict that the gliding up/up line will be very close to what we will get performance wise for clean configuration stall at fully loaded weight when the BoX version comes out.  (Was there a weight given for those tests?)

Don't know why this "obsession" about "turning rates" persists? You only need to pull to get the final deflection angle before opening fire - this is what the instantaneous turn rate is for. Continuous turning is not healthy even if you are driving a Spit - there are better alternatives like yoyos.

 

Because it is measurable in game and was measured in RL tests, so this is one of the few ways the match of aerodynamic qualities between game and real machine can be checked by us players, for those that enjoy that sort of thing. 

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Or perhaps the engagement might have started at moderate to high speed, and the P-40 made the most of his superior initial turn rate and firepower to secure the kill before he ran out of excess energy and was left with the inferior sustained turn rate shown there in your table?

 

Exactly: Any plane with an energy advantage can convert that to a high instantaneous turn rate pulling inside a better stationary turning plane.

 

Don't know why this "obsession" about "turning rates" persists? You only need to pull to get the final deflection angle before opening fire - this is what the instantaneous turn rate is for. Continuous turning is not healthy even if you are driving a Spit - there are better alternatives like yoyos.

 

The reason for the ”obsession” with stationary turn rate is not that it in itself is the path to Nirvana but that with a good stationary turn rate performance follows good energy retention when pulling g’s. So, given you want to retain as much energy when you Yo-Yo or pull that lead in a turn, if you have a better stationary turn rate capability you will have more energy/speed after a given manouver. So, a plane with a 20% stationary turn capability deficit will run out of steam and be forced to break of an attack earlier when manouvering than one that is not handicapped in this way.

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