Landing skid/ undercarriage design

[extrapilot]

Yea, that is the standard tactic. It is just a matter of tuning the system, and that may change with significant changes in mass or mass distribution. Almost all machines go though 2 phases of resonance during spoolup, but it is usually subtle enough to be a non-event. And there may be some benefit of getting the rotor up to speed rapidly- since the acceleration is likely to pin the blades in a lag condition though these regions.

Sometimes, you just get lucky and have a setup that does not want to resonate. But almost always, you can excite it with a skid bounce followed immediately with a setdown, if you are near the resonant point.

It is were me and I had a known configuration, Id just proxy the expensive components with ballast, and do some test flights to see how immune the system is. It is just SUPER complicated to model- there are multiple Masters/PhD papers on the subject. The problem is, you don’t tend to see any on 2-bladed designs, since it is just not normally seen when you don’t have lag hinges. There is another mode in flap, but with teetering heads, again, not normal. For us, we have several variants (i.e. DFC or stiff dampers, with lag hinges) that put the system at risk- so a bit of uncharted territory as regards math models and test data.

Kind regards