|"Robinson R22 Helicopter hovering" by Jitze Couperus. Licensed under CC BY 2.0 via Wikimedia Commons|
The tail rotor on a helicopter provides a turning force to counteract the torque from the main rotor. But as well as turning the helicopter, the tail rotor also applies a sideways force on it. This tends to push the helicopter to the right, if the main rotor spins anticlockwise. To hover or fly straight, the helicopter has to be tilted (rolled) slightly to the left to balance this force. That means it needs more weight on the right-hand side to keep it stable when it's tilted like that. If there were too much weight on the left side, the cyclic control wouldn't be able to generate enough force to roll the helicopter back to the right.
For this reason, if you're flying an R22 solo, you have to sit in the right seat, to keep it balanced, and you have to weigh at least 59 kg. If it's carrying auxiliary fuel, that increases to 61 kg. I'm not that much of a lightweight, but it's close enough that I would probably need to take on some ballast if I were flying with a heavy person in the left seat, or the max weight of cargo, in order to keep the aircraft centre of gravity within its limits.
|"Robinson R44 Raven G-RAVN arp" by Adrian Pingstone. Licensed under Public Domain via Wikimedia Commons.|
With all doors installed, a solo pilot weight of 150 lb (68 kg) or greater will ensure CG within limits. For lower pilot weight, compute weight and balance; removable ballast may be required to obtain CG at or forward of aft limitSo if I want to learn to fly a helicopter, I should start working on my ballast now. A bacon butty for breakfast and a couple of pork pies before lunch should set me on the right path.