Disc loading, Dragon Wings. Some thoughts.

[C. Beaty]

Originally Posted by cburg

TI asked my gyro instructor if it was possible to tail slide or “flat spin” (engine-out) a gyro and whether the undercarriage would simply rotate 180 depending on weight distribution. Your thoughts?Chuck

A gyro with dead engine won’t “flat spin.” It must have the prop blast over a deflected rudder.

Gyro flat spins are unrelated to airplane flat spins; hanging from a ball bearing with prop blast over a deflected rudder, they are more related to ice skater pirouettes.

Of course they will tail slide with dead engine.

[Penguin]

Originally Posted by C. Beaty

JC, I’m not certain about the numbers but I think DW rotor blades weigh 1.6 lb/ft and standard blades have 0.5 lb. tip weights; “cruzer” blades have 3 lb. tip weights.

If my numbers are correct, 3 lb. tip weights increase the MOI of a 23 ft. rotor by a factor of ~1.5.

Maybe Ernie will see this and correct my numbers.

That's pretty close.
I weighed my std. 23' DWs this morning at 42lbs.

[C. Beaty]

Yeah- the 2.5” x ¾” hub bar weighs 2¼ lb/ft.

[Jean Claude]

Originally Posted by C. Beaty

JC, one might expect autorotation to become unstable and stop much beyond µ=0.35 but there is no record of such an accident.
My own experiments at low speed lead me to believe it is not possible to force a stable airfoil sufficiently past 0.35 to cause catastrophic stopping of autorotation.
But if I’m wrong, it won’t be the first time.

What I mean, Chuck, is that the behavior appears to be safe just outside the theoretical simplicity of constant pitch blades. If this is so, then Vne is not as safe for all gyroplanes.

[Resasi]

That would be a good point to clarify if possible. In reality I, like most of us, like to approach the edges of any envelope with great caution, but nice to be aware of what the results might possibly be if one were to inadvertently stray over the limit.