Originally Posted by
Lonewolf_50
It depends.
Here's a second hand story from my CO (many years ago) who flew Huey Gunships (HAL-3 in Viet Nam).
By the book, you need to be able to hover at X' without a 2% droop in your Nr in order to take off without offloading some fuel ...
The Huey's tended to be overloaded, so they used an "in ground effect running takeoff" to get around that limitation.
As the helicopter got a bit more airspeed, the power required reduced so there was enough power to fly away and once through translational lift, you'd soon burn off enough fuel to be back in limits.
But during non war training ops, you'd not have done that.
That was our rule of thumb in the 212 in the Jungle. If you had 80-82% in the 4ft hover then you'd be able to get out of the LP vertically.