Vs1g and Vs are two speeds majorly abbreviated for stalling conditions.
Vs1g
-corresponds to maximum lift coefficient i.e. Clmax. Clmax is the condition when angle of attack is maximum and load factor is equal to one.
Vs
-corresponds to conventional stall condition. This is the time when lift suddenly collapses and load factor is less than one.
Vs is less than Vs1g
Vsr : It stands for reference stall speed selected by manufacturer for regulator purposes. Vsr can not be less than Vs1 so for all practical purposes Vsr is equal to Vs1g.
Key Notes:
- Vsr = Vs1g
- Vs is less than Vs1g
- Vs = 0.94 Vs1g
- V2min = 1.13 Vs1g