Definition
VMINI is the minimum airspeed at which a helicopter is approved to be operated under instrument flight rules (IFR). It is established by the manufacturer and published in the Rotorcraft Flight Manual as part of the helicopter's IFR operating limitations.
Plain English
The slowest speed a helicopter is allowed to fly when operating in the clouds or in low-visibility conditions on an instrument flight plan.
Context Anchor
Seen in aircraft performance, limitations, and instrument procedure discussions where IFR operating speeds matter.
Derivation
The 'V' comes from the French 'vitesse,' meaning speed — the same convention used for all V-speeds (VNE, VNO, VS, etc.). 'MINI' is short for minimum, and 'IFR' specifies the regime in which this limit applies. So VMINI literally reads as 'speed, minimum, IFR.'
Why Pilots Care
Flying below this speed in instrument conditions risks loss of control or inability to meet required climb gradients and track accuracy.
Intuition Check
Do not treat VMINI as the same thing as stall speed. It is the minimum approved IFR operating speed for that aircraft, which may be higher than the speed where the wing would stall.
Example Sentence 1
The pilot kept the helicopter slightly above VMINI throughout the approach to remain within IFR limitations.
Example Sentence 2
During the missed approach, the crew accelerated above VMINI to ensure positive climb performance in IMC.