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.