The discrete-time controller in the form of a difference equation is implemented into a standard quadcopter flight controller for quadcopter altitude control, where the altitude is the controlled measured value. Two control design methods that are H∞ optimization and the fixed-structure control system tuning are used to obtain the linear controller for identified linearized transfer function of quadcopter vertical translation dynamics. The problem of a balance of requirements to the load sensitivity function and the noise sensitivity function H∞ norms taking into account the stability margins radius is considered. The results of experimental flights with several obtained controllers are presented.