Generally speaking, the model rotorcraft is inefficient. We calculate according to three times the power required by a fixed wing (trainer) with the same weight:

It weighs about 3KG.

What is the minimum power required by the engine? How should I calculate it? Can a friend explain it to me? Thank you very much.

A 3KG fixed-wing trainer needs about 150W power to barely take off and keep flying horizontally.

The rotorcraft needs to be multiplied by 3 to get 450W W W.

If a 4S lithium battery is used, the current will be nearly 30A according to 16V.

This kind of relatively large brushless motor is very abundant on Taobao and easy to find.