Peter Lürkens 30 Posted January 12, 2011 Share Posted January 12, 2011 I have noticed, that the PBY has a very low sink with gear retracted at low speed and throttles on idle, i.e. 400 ft/min at 70-80 kn, which results in a glide ratio of up to 18 and higher. Further conditions were 50% fuel and nominal loading (PBY-6A B64). Is this on purpose and the Catalina is really that good at that, or is this one more of the limitations of FSX? Indeed, I have the feeling that also stock aircraft show the effect of low drag at low speed. As it is, it seems to make water landings a bit of a lottery, as the Catalina soars endlessly until airspeed bleeds and the aircraft settles down on the water. Would be interesting to know if the real plane behaves the same. Cheers, Peter Link to comment Share on other sites More sharing options...
Snave 466 Posted January 14, 2011 Share Posted January 14, 2011 Well acorrding to THIS it's 5.06:1, but as it doesn't state at what weight I don't know whether but a large, low-aspect ratio wing tends to offer certain low-speed airflow advantages, but of course the PBY was designed with early Thirties technology and was already considered obsolescent at the outbreak of WWII. You can read much more on LAR wings in this technical paper which discusses many of its features Here The truth in FSX is that lift/drag is all over the shop after the active .air file entries were butchered in the transition from FS2004 to FSX and the adjustments that can be made in the later sim are somewhat `coarse` compared to those in the previous version. But certainly I wouldn't see much of a problem of a lightly-loaded Cat reaching 18:1 in advantageous conditions. After all, the standard method of attack for the Black Cats used in night attack ops was to throttle back and carry out a glide approach to lessen approach noise, and that would have been with arms, ammo and munitions on board, as well as enough fuel to return to base, obviously. And then there is the impact of the cowl flaps... Link to comment Share on other sites More sharing options...
Peter Lürkens 30 Posted January 14, 2011 Author Share Posted January 14, 2011 Well acorrding to THIS it's 5.06:1, but as it doesn't state at what weight. And it's referenced to 154 mph, which is not exactly the flare speed. Real glider's glide ratio is oinly little affected by weight, only the speeds (sink and airspeed) are scaled according the weight. ... is all over the shop ... Not sure what is meant by that. After all, the standard method of attack for the Black Cats used in night attack ops was to throttle back and carry out a glide approach to lessen approach noise, and that would have been with arms, ammo and munitions on board, as well as enough fuel to return to base, obviously. Makes sense. And then there is the impact of the cowl flaps... Forgot to mention: they were open (thanks to the nice checklist!) Occasionally, I have the effect, that a lot of drag was present during take-off, which let airspeed saturate at 85 kn, even when airborne (so no water drag effect). Reloading the plane fixes it. Cheers, Peter Link to comment Share on other sites More sharing options...
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