Biplane parasitic drag

[marceldup 0]

Hi Guys, my first post here.I’ve been using AirWrench over the last few days to update my Ag-Cat for FSX, but I’m struggling with a few aspects peculiar to this plane. The first problem is the large change in weight during flight. I’m using the ballast functionality in FSX to simulate the chemical load. The flying weight changes from ±6000kg to ±3500kg as the chemical hopper empties, but there is only a small change in airspeed (with the engine operating at a constant power setting). I think this can be achieved by making parasitic drag dominant over the induced drag?Do you thing AirWrench is a suitable tool to handle this, or will I have to dig deeper into the files themselves?CheersMarcel

[budsurf 0]

Hi, I'm no expert but here's an idea I have experimented with in Fs9. Bear with me here, the possible application to your situation will become apparent soon. I noticed that in Fs9, the propellor drag was not very realistic - while flying, when you chop the power, the propellor should soon produce a major amount of drag, and the plane will slow until it is flying at a speed where the propellor is again producing thrust. To experiment, I introduced an invisible spoiler into the aircraft .air file and experimented with XML gauge code which activated the spoiler through a series of speed ranges using the sim variables - throttle lever position, and indicated airspeed. Example code: (A:GENERAL ENG1 THROTTLE LEVER POSITION,percent) 90 < (A:GENERAL ENG1 THROTTLE LEVER POSITION,percent) 76 > (A:AIRSPEED INDICATED,knots) 125 > && && if{ 16384 (>K:SPOILERS_SET) } By tuning a series of such speed ranges I have made serviceable prop-drag gauges for several planes like the Beaver, Dash8 and E120. Yes I know, very crude, but in the sim this works amazingly well. So, in your situation, you could again introduce an invisible spoiler - but this time have it activated according to aircraft weight, where with a full load there would be a slight increase in drag. As the load decreased, the drag would decrease. Anyhow, the fun is in the experimenting after all.

[marceldup 0]

Hi, I'm no expert but here's an idea I have experimented with in Fs9. Bear with me here, the possible application to your situation will become apparent soon. I noticed that in Fs9, the propellor drag was not very realistic - while flying, when you chop the power, the propellor should soon produce a major amount of drag, and the plane will slow until it is flying at a speed where the propellor is again producing thrust. To experiment, I introduced an invisible spoiler into the aircraft .air file and experimented with XML gauge code which activated the spoiler through a series of speed ranges using the sim variables - throttle lever position, and indicated airspeed. Example code: (A:GENERAL ENG1 THROTTLE LEVER POSITION,percent) 90 < (A:GENERAL ENG1 THROTTLE LEVER POSITION,percent) 76 > (A:AIRSPEED INDICATED,knots) 125 > && && if{ 16384 (>K:SPOILERS_SET) } By tuning a series of such speed ranges I have made serviceable prop-drag gauges for several planes like the Beaver, Dash8 and E120. Yes I know, very crude, but in the sim this works amazingly well. So, in your situation, you could again introduce an invisible spoiler - but this time have it activated according to aircraft weight, where with a full load there would be a slight increase in drag. As the load decreased, the drag would decrease. Anyhow, the fun is in the experimenting after all.

Thanks, that is useful info.Marcel