The climb flight path angle is measured relative to the ground and so is affected by headwind and tailwind, except in a vertical climb.

So, the flight path angle will:

• Increase when climbing in headwind.
• Decrease when climbing in tailwind.

Best Rate of Climb Airspeed (V_Y) is the airspeed at which the helicopter has the best performance in ascent, where the helicopter has the biggest difference between power required and power available and gives the maximum altitude gained in the shortest time.

Best Angle of Climb Airspeed (V_X) is defined as the airspeed at which the helicopter will achieve the best angle of climb. V_X speed is maintained during climb to clear obstacles and gives the greatest altitude gained in the shortest horizontal distance.

Both airspeeds are not affected by the wind.

Also, the wind does not affect the Rate of Climb or the fuel used to climb to top of climb, but it does affect the position of the helicopter over the ground when it reaches top of climb.