Spit IIa

Originally Posted by TomcatViP

Those curves are contestable regarding how the both planes shld hve performed:
- first: on the ground of the knowledge of both nation at the time of the test/calculation (1940)
- Secondly : on the base of the contradictions that a modern analysis would tell us

First pt : If British engineer in 1940 had let an elliptical winged (EW) fighter be the most advanced defense they had allowed to be put on the frontline, for sure they were not aware of the advance Germans had made in that grounds. Remind that EW are the panacea only when dealing with inviscid flows etc... etc... Look at max Cl of both plane, max Pow and wing loading.

I know that I can be annoying but those value and the fact that the wing thickness of the spit is lower tell us that there SHLD be an inversion in turn radius as the speed decrease. in other terms the spit shld turn tighter at high speed but hve a greater radius of turn when the speed is low.

In other words they couldn't hve found any other value as their assumptions were made on false grounds.

I must admit that I had some difficulties reading the graph in terms of turn radius at it seemed to me that whatever g-line I regarded both spit and 109 would have had approximately the same turn radius. As this is probably not true I dismissed my way of reading the chart with respect to turn radius.

My guess anyhow is that what is of importance in the chart IvanK posted is the turn time for a full circle. According to IvanK's chart the turn rate between the spit and the 109 is pretty close. This does not say anything about turn radius.

If somebody could help be decypher the chart wrt turn radius I'd be happy to listen.

[TomcatViP]

How to read the chart :

Choose a speed for a plane -> then select your G level / bank angle - > read the time to 360° *-> then compare to the other plane

*You can also read the nearest dotted line that give you the nearest computed radius but as the speed V=d/t if you hve V (cte) and t then d is alrdy in your hands

Alternatively you can follow a firm line that stand for a level turn (cte height) -> you can then see how much G/ bank angle is needed at a given speed for a given plane and what wld be the radius of turn.

[IvanK]

Originally Posted by TomcatViP

Those curves are contestable regarding how the both planes shld hve performed:
- first: on the ground of the knowledge of both nation at the time of the test/calculation (1940)
- Secondly : on the base of the contradictions that a modern analysis would tell us

First pt : If British engineer in 1940 had let an elliptical winged (EW) fighter be the most advanced defense they had allowed to be put on the frontline, for sure they were not aware of the advance Germans had made in that grounds. Remind that EW are the panacea only when dealing with inviscid flows etc... etc... Look at max Cl of both plane, max Pow and wing loading.

I know that I can be annoying but those value and the fact that the wing thickness of the spit is lower tell us that there SHLD be an inversion in turn radius as the speed decrease. in other terms the spit shld turn tighter at high speed but hve a greater radius of turn when the speed is low.

In other words they couldn't hve found any other value as their assumptions were made on false grounds.

The chart is one of the earliest plan Fan plots (or "Dog house plot" in US terms) that I have seen. As such its straight Energy Manoeuvrability theory that is Excess Power (ps) applied to the turning problem. As such it takes into account the total Airframe engine combination so Wing loading,planform,wing section etc is part and parcel of plot. The actual RAE derivation of these charts is discussed in great detail in AVIA 6/2366 RAE report "Notes on the dogfight" A more detailed version of the Spit fan plot chart from this report is shown below. In this case the study also takes into account various extrapolated wing areas and therefore wing loading etc.



I dont agree that their assumptions were made on false grounds. Everything I have read in these reports indicates to me that the boffins doing this work were really on top of their game. Here is some of the data they were using in this report obtained from a physical specimen BF109E3:





The USN also produced a comprehensive study on turn performance on the F2B (Buffalo) that is equally involved and again is based on straight out EM theory applied to the turn problem and again chock full of fan plots.

Here is another chart from the same source source document as the original Fan plot came from (AVIA 5/2394 "Messerschmitt Me.109 Handling and Manoeuvrability Tests" which is a pretty exhaustive 63 page document. This chart provides similar data to the fan plot but perhaps in a more easily digestible format as both Spitfire and 109 plots are overlayed on the same chart.

[fruitbat]

Thanks for posting IvanK, really interesting stuff.

Resumee:

The Spit has a turn radius of 700 ft (about 215m) and the 109 slightly below 900 ft (275 m). The turn rate is at medium and high speed similar (slight advantage for spit at medium speed, tendency vice-versa for high speed). Good advantage for spit at low speed. Altitude loss higher for 109 during full circle (nearly 0 for spit at medium speed, 5° for 109 at medium speed)

Does not feel that way in game ...

[GF_Mastiff]

Originally Posted by 41Sqn_Stormcrow

Resumee:

The Spit has a turn radius of 700 ft (about 215m) and the 109 slightly below 900 ft (275 m). The turn rate is at medium and high speed similar (slight advantage for spit at medium speed, tendency vice-versa for high speed). Good advantage for spit at low speed. Altitude loss higher for 109 during full circle (nearly 0 for spit at medium speed, 5° for 109 at medium speed)

Does not feel that way in game ...

no it doesnt I fly the spitIa and the 109s keep in a turn at medium speed the spit can not out turn them. or instant climb like the 109s E4s.

[CWMV]

Originally Posted by GF_Mastiff

no it doesnt I fly the spitIa and the 109s keep in a turn at medium speed the spit can not out turn them. or instant climb like the 109s E4s.

In truth you need to realize that you piloting ability, or lack there of, are more likely the reason why you cant conquer the 109's.

You in game experience simply does not hold up to numbers, so if you have some charts post them, please! Otherwise your "The 109's are sooo much better than me" just show your a bad pilot.

[SEE]

How do you know he is a bad pilot? How would you react if you were told that you were a bad pilot because you cannot deal with a Spit Mk2? Pretty sure you would jump on the FM differences and state your case based on evidence but be a tad annoyed that someone simply tells you to fly better.

The current Spit Mk1a is not right in its specification or its FM. If people are discussing these issues then it is more constructive to debate them rather than impy posters are incompetent. It makes posters feel that their opinion is worthless on a baseless assumption. Piloting skills arguments are valid but not always helpful when used almost as an insult - hopefully you didn't mean to imply it in that sense.

The Clod Spit Mk1a is very capable at altitude and handles beautifully but the Bfs have had a lot of goodies in previous patches. Spit Mk1 jockeys are still stuck with a 'Boost Cut Out' that does nothing, a top speed of 245mph, a two speed prop and debatable Neg G modelling.

[CWMV]

Originally Posted by SEE

How do you know he is a bad pilot? How would you react if you were told that you were a bad pilot because you cannot deal with a Spit Mk2? Pretty sure you would jump on the FM differences and state your case based on evidence but be a tad annoyed that someone simply tells you to fly better.

The current Spit Mk1a is not right in its specification or its FM. If people are discussing these issues then it is more constructive to debate them rather than impy posters are incompetent. It makes posters feel that their opinion is worthless on a baseless assumption.

The Clod Spit Mk1a is very capable at altitude and handles beautifully but the Bfs have had a lot of goodies in previous patches. Spit Mk1 jockeys are still stuck with a 'Boost Cut Out' that does nothing, a top speed of 245mph, a two speed prop and debatable Neg G modelling.

Id respond by posting a graph showing the under-modeled nature of the 109E-4.
Wait a minute...

And I agree that EVERYTHING in the game needs to have its FM reworked, including the current inaccurate Spits.

I don't know him or his abilities, whats more is that without something to back his opinion its pointless.
I mean how many times have we seen this in the past with IL2?
"Aircraft A is over-modeled because when I'm flying aircraft B it shoots me down every time!"
....

Really though, what worth is an opinion if you don't have any data to base it off of?

Trying to base the truth of an FM off of "Well it cant be right because I cant shoot them down in game" is ludicrous.
Saying that an aircraft is under-modeled in regard to a certain aspect (say 109E's top speed?) and then posting technical information showing the difference from the accepted in game performance of that aircraft is another thing entirely.

Now I did ask him to post his evidence, or something at all that backs his claim because were after the truth here, right?

And I have to admit I took a short temper with him because of his other "The 109 is SOOOOOOOOOOOOOOOOOOOOOOOOOOO uber!" threads. its just annoying.
Sorry for any offense, none intended.

[SEE]

It's Ok bud, I get a bit defensive regards the Spit v BF arguments, so apolgies if I over reacted to your post. I am sure you meant well.....