why aren’t all helicopters quadcopters?

Question

So – clearly quadcopters are more stable (see all the drones), so why aren’t actual helicopters all quad copters?

In: 5

Answer 1

An early experimental VTOL aircraft, the Bell X-22

https://en.wikipedia.org/wiki/Bell_X-22

was a “quad copter” I suppose.

It had many problems, starting with the fact that it predates anything you’d call computers, hence had no sophisticated automatic controls.

But the biggest problem was a phenomenon called “recirculation”, where airflow near the ground was deflected back around into the ducts, seriously reducing lift.