# Determining Gross Weight and Stall Density of a Helicopter

## How can we calculate the gross weight of a helicopter based on the given data?

What density will cause the helicopter to stall?

To calculate the gross weight of the helicopter, we can utilize the lift equation, which considers factors such as air density, rotor blade area, velocity of the rotor blade, and average lift coefficient. The density at which the helicopter will stall can be determined using the maximum lift coefficient.

Given the specific data for a four-bladed helicopter hovering at a certain altitude with known blade chord, radius, rotor rotation speed, and average lift coefficient, we can use these values to calculate the gross weight of the helicopter. By applying the lift equation and considering the maximum lift coefficient, we can also find the density at which the helicopter will stall.

The gross weight of the helicopter can be calculated by first determining the lift using the given formula and then converting it to weight using the acceleration due to gravity. Additionally, the density at which the helicopter will stall can be found by rearranging the equation with the maximum lift coefficient to solve for density.