Originally posted by Knegel
I agree to your La7/5 assumptions, only that the la5 wasnt allowed to climb with WEP(overheating in a few sec) and that the WEP was a real short time WEP to disengage, while the La7 could use it up to 10min.
Therfor the La5 i would count as a 1650HP plane, while the La7 is more a 1850HP plane(same like the 109G2 is more a 1310/1400@2000m plane, while the late 109G6 was more a 1475/1520@2000m plane.
Well the performance figure re turn and climb are nearly the same for both ac when WEP is not engaged.
I have checked the acceleration rates of the AH la5FN and La7 (no WEP)and compared to each other they behave as we would expect.
Actually AH models WEP duration on the La5FN the same as the La7. (or seems to)
The closer cowl of the La7 did cause air to flow more efficiently around the cylinder heads than on the slightly more bulbous La5 cowl.
Czech pilots flying La5FN's did coment that engine temperature management was a permanent concern. Claiming 2 minutes WEP was the max.
German La5FN trials indicated that engine temperature rapidly rose too high climbing under WEP.
One set of Russian curves I have dont show any WEP max speeds for the La5FN whilst showing them (and their duration) for the La5F and the La7.
Unfortunately hard data on the la5FN is (other than the german trials) is rare.
In Conclusion
I think it is difficult for HTC to get FM's spot on in all respects when there is such greyness around a lot of the data concerned. The priority would seem to get the comparable ac to ac performance as correct as possible.
It would seem to me that the comparable AH sustained dive rates of some ac do not hold true to the historical reference or even indeed to what we would expect.
Its difficult to test this.
The effect of this on combat would be the ability to run away and the effects of throttle control (at high speed) on deceleration.
I have argued above how drag free the La7 was compared to other radials but there are some La7 wing aspects that have always interseted me and yet I am always advised it is of no consequence.
1) The la7 wing is triangular in shape (much more so than other comparable AH ac). There is a chart somewhere that shows the lift pattern across such a wing. How does this effect how we consider wing loading and aspect ratios compared to a rectangular wing?
2)The triangular wing has a long root surface with the fuselage. A large proportion of the wing is subject to propwash. A large portion of the wing root is behind the engine cowl due to the fuselage taper. How would this effect drag in this area compared to a rectangular wing of similar length and surface area?
3)The distance between the C of G and the tail section is shorter than nearly every other ac modelled in AH. The horizontal tail section area is corresepondingly much greater that other comparable ac. The elevator areas are significantly larger than other ac (of similar size). If this must be larger does it have effects upon pure and induced drag? Would this component be more significant in straight line flight? would it be removed in turn?
