EDIT - You may need to download the 'limitlessspin' mod for this to work properly. Simpleplanes imposes a limit on how fast any 'non propeller' parts can spin, but this gets rid of it. I've used it with no bugs on latest version. All credit to original author of mod.

Just a bit of fun making a helicopter without helicopter specific parts and being very inefficient by driving the 'rotors' directly with jet thrust! It's stable without the gyros - they are only there to provide a means of control, the rotor disc's gyroscopic forces are so strong that using hinges etc causes the body to rotate instead of the disc! Go full power and use VTOL to control blade angle like any other helicopter, and small quick movements to correct yaw!