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Old 07-15-2013, 07:55 PM
horseback horseback is offline
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Quote:
Originally Posted by gaunt1 View Post
Dont know... Still fishy for me. La-5FN is only 150hp more powerful, but according to NII VVS tests, it is actually heavier (60-100kg) than La-5F. I strongly suspect that ingame FM is based on the performance of the prototype SN 39210102. If you look at horseback's chart, the performance of the FN is suspiciously better than the F. It should be of course better than the F, but not that much, maybe only 15-20%.
The tables in Soviet Combat Aircraft Volume 1 by Yefim Gordon and Dmitri Khazanov show a top speed of 573 kph at sea level for the -5FN and 551 kph for the -5F, and I got a (rounded off) 560 kph indicated at 100m for the -5FN and a (rounded off) 530 kph for the -5F. True airspeed would be somewhere north of 578 kph and 548 kph respectively, so both aircraft models appear to be close to the RL records. Further reading seems to indicate that the -5F was flown most often with the canopy open in practice, due to accumulated exhaust fumes and (possibly) poor visibility, so there may be some compensation for that in the FM.

However, this is an acceleration comparison, and the extra horsepower of the M-82FN translated into better acceleration even more than better top speed, which with the similar airframes meant about the same major limiter to top speed; the -5FN reaches its intervals sooner (and really, it is only a second and a fraction difference at the initial stages, but the differences are cumulative--they add up over time).

Let's look at another indicator of the added power of the M-82FN taken from the same book I referred to earlier; the takeoff runs of the production La-5F were measured at 350m--compare that to the production La-5FN's 290m. That's a good deal more than a 10-12% difference right there, and I think it means that the FMs for these two aircraft are fairly accurate in this respect within the limits of the game engine.

cheers

horseback

Last edited by horseback; 07-15-2013 at 08:08 PM.
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