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I am still wondering why a plane with the power-to-weight of the La-9 doesn't climb at least 1,000 feet per minute better than it does.
We must remember that acceleration is not only a function of power-to-weight, this only true at zero airspeed and max power, rather it is a function of excess power-to-weight. If an aircraft is using all of its power to maintain a given airspeed, it will not out accelerate a lesser powered aircraft that is not using all of its power to maintain that airspeed. This is one of the advantages of the P-51 had since it almost always used less power to maintain a given airspeed than other WW2 prop fighters. Now according to chart of spitfire performance the F8F-2 (the charts for the F8F-1B seem unbelievable showing combat power at 2750 hp at SL) generating 2500 hp at SL with a max speed of 387 mph, whereas the Russian site (believable ?) shows the La-9 generating 1850 hp at SL with a max speed of 397 mph. If these numbers are true, the La-9 is much cleaner than the F8F and therefore will need less power to operate at any given airspeed. At SL and 387 mph, the La-9 will out accelerate the F8F because it has the excess power to do so. At other envelop points, calculations would have to be run to see which aircraft would out accelerate the other, but it is possible for the La-9 to also out accelerate the F8F at other envelop points.
You know, although I look at a Bearcat every time I go to the museum and notice the gear legs that break at the top to fold VERY strangely for ground clearance, I totally space-cased the prop disc area.
Thanks, Shortround! It goes a long way toward some explanation that at least makes sense.
One thing that makes me question the notion that the La9 will outaccelerate the F8F is the difference in climb rate...the F8F climbs at more than 1000 fpm faster than the La9...granted, lift plays into this, and the F8F has a higher lift wing than the La9, but does that wing account for all of the difference in climb rates? I would be shocked if that were the case, which leads me to believe the F8F simply makes more efficient use of it's power than does the La9, which also leads me to believe that F8F would accelerate better than the La9...you made a good point with the P-51, which has a similar laminar flow wing to that of La9, and the "D" model has a climb rate that's almost identical to that of the La9, and I highly doubt a P-51 will outaccelerate a Bearcat...
One thing that makes me question the notion that the La9 will outaccelerate the F8F is the difference in climb rate...the F8F climbs at more than 1000 fpm faster than the La9...granted, lift plays into this, and the F8F has a higher lift wing than the La9, but does that wing account for all of the difference in climb rates? I would be shocked if that were the case, which leads me to believe the F8F simply makes more efficient use of it's power than does the La9, which also leads me to believe that F8F would accelerate better than the La9...you made a good point with the P-51, which has a similar laminar flow wing to that of La9, and the "D" model has a climb rate that's almost identical to that of the La9, and I highly doubt a P-51 will outaccelerate a Bearcat...
And these are the exact conversions the nations used at the time (I downloaded the attachment)? For example 14.696 was used for the measurement and not 14.69595 PSI, and so on...These are not linear units of equivalence, they are national standard units of manifold atmospheric pressure.
Sure...I can post an "extended" chart if anyone is interested, that covers idle to Reno racing levels.
And this was gauge pressure?The Russians typically used mm H2O, not mm HG
One poster mentioned the Griffon Spitfire v the P-51. I believe the appropriate comparison would be between the P-51H and the Spitfire and I suspect the P51 might come out on top.