Ask a Dutch guy on how to perform a dutch roll.
No need for swept wings to experience the dutch roll phenomenon.
E.g. the Cessna 310 tends to dutch roll even in light turbulence.
Not a nice ride in the back seats.
The old FSX Milviz 310 simulated this nicely.
I flew the 303, same story, really makes you sick when the YD isn’t working. Seems to be a Cessna problem .
Likely. I tried to induce a dutch roll in a level d 737ng sim… Nothing happened.
@JoseColme YD off during your attempt?
The CRJ was awful with full flaps and the YD inop because it developed a divergent dutch roll.
NO fun, not even in the sim.
That’s a real stress test for any sim. Tried it in MSFS, XP, and DCS. MSFS was the most responsive (bouncy?). I’m not sure if any of my tests were that accurate. Fun stuff! I think this is why I like the Stearman so much; it’s the least annoying. Nice explanation here.
It is depending on so much factors, lateral stability versus directional stability, swept wings usually are more prone to Dutch roll as yawing will cause the effective chord to change. Dihedral and anhedral will change lateral stability. The size of the vertical fin, bigger stabilizer increases directional stability but depending on hight of the fin might also cause a stabilizing effect on the roll (the force created by the vertical stab is above the CG so tend to cause a roll in opposite direction). And so on…
I will check my Oxford books tonight when I’m back from flying to see if there is something interesting in there to share.
The aircraft itself might not be prone to Dutch roll but you can still make it Dutch roll with a little help. If you cycle the rudder left and right at the correct frequency you can make any plane Dutch roll. You can best see this when looking directly over the wing, you’ll notice the yaw and roll will be out of synch upon finding the right frequency.
One thing I noticed in the Stearman, when I roll and let go of the stick, the stick centers, but the ailerons flutter up and down a bit before stabilizing. This is probably not like real life, and I don’t know if this is affecting the roll. I do not see any dutch roll behavior in the Stearman, but this is probably not a good aircraft to test for this. I think a longer fuselage with a larger tail fin would be the best platform for testing.
Edit: this fluttering is from my Virpil flight stick. The ailerons mirror the bouncy behavior in the stick.
I tried this with the default MD-80 in XPlane with YD off. Just as you think you’ve got a good swing going, let go of the rudders, then it just settles back in to a stable flight.
Can anybody who has the FJS727 try it in XP11?
I’m pretty sure the 747 is modeled in the traditional way of “don’t make dutch roll a thing so the YD doesn’t have to do anything” regime. Because since they dialed up the adverse yaw in the recent update the big iron is now super uncoordinated in a turn. Turning the YD on and off doesn’t make a difference.
Another thing I noticed when I was doing these tests was both XP11 and MSFS “cheat” the adverse yaw by using a “phantom rudder”. If you turn on debug mode you can see that the yawing forces are coming from the TAIL, NOT THE WINGS. At least that’s how all the default planes do it.
I guess X-plane is more reliable in this regime as you can’t really “cheat” via a cfg file?
Doesn’t make a difference since the forces are not originated from the wings. But they both give you the sensation of Adv yaw if you don’t think about it too hard. So it’s a good way to save some computing resources. Flight models are pretty much all single threaded so it’s a good compromise.
I started turning off the yd first and nothing. Ended up with all hydraulics off trying to induce it. Either the 737 avoids dutch rolls really well or the sim doesn’t show it.
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