The following abbreviations and symbols are used in articles throughout this website. These are mostly consistent with other helicopter literature.
|
\(\alpha\) |
angle of attack of the fuselage, rotor plane or a blade section depending on the context |
| A | rotor area |
| AFCS | automatic flight control system |
| \(\beta\) | sideslip angle or blade flapping angle |
| \(\beta_C\) | main rotor longitudinal flapping |
| \(\beta_S\) | main rotor lateral flapping |
| \(C_L\) | roll moment coefficient (\(L/\rho AR(\Omega R)^2\)) |
| \(C_M\) | pitch moment coefficient (\(M/\rho A R(\Omega R)^2\)) |
| \(C_T\) | rotor thrust coefficient (\(T/\rho A (\Omega R)^2\)) |
| CCW | counterclockwise |
| CW | clockwise |
| D | drag force |
| F | force |
| GW | gross weight |
| \(\lambda\) | rotor inflow ratio ((\(V\sin \alpha + v)/\Omega R\)) |
| L | lift force |
| LZ | landing zone |
| \(\mu\) | rotor advance ratio (\(V\cos \alpha /\Omega R\)) |
| \(m\) | mass |
| M | pitch moment |
| N | yaw moment |
| NR | main rotor speed as a percent of nominal speed |
| \(\Omega\) | main rotor speed |
| \(\phi\) | Euler roll angle |
| \(\psi\) | Euler yaw angle |
| \(\Psi\) | main rotor azimuth angle |
| \(p\) | body roll rate |
| \(q\) | body pitch rate |
| \(r\) | body yaw rate |
| \(\rho\) | air density |
| \(r\) | distance of blade section from rotor center |
| R | main rotor radius |
| SAS | stability augmentation system |
| T | rotor thrust |
| TAS | true airspeed |
| \(\theta\) | Euler pitch angle |
| \(\theta_0\) | collective control angle |
| \(\theta_C\) | lateral cyclic blade angle |
| \(\theta_S\) | longitudinal cyclic blade angle |
| \(u\) | body axis forward velocity |
| \(v\) | body axis lateral velocity |
| \(V\) | total velocity of air relative to helicopter or rotor |
| \(v_i\) | rotor-induced velocity |
| \(w\) | body axis vertical velocity |
| \(y\) | out-of-plane displacement of a blade section |