A supervision system for an aircraft for monitoring a safe charging of portable electrical devices of a passenger who may be in an attentive or an inattentive state, comprising a passenger seat, a power supply station assigned to the seat and used to supply electrical power to the portable electrical device, the portable electrical device being connected to the power supply station, a camera, which detects the state of the passenger situated on the seat, and an arrangement to distinguish whether the passenger is in an attentive or inattentive state. A method for safe charging of portable electrical devices is also presented and described, comprising the steps of detecting a passenger with a camera, analyzing whether the passenger is in an attentive state or in an inattentive state, and, if the passenger is in an attentive state, supplying a power supply station with electrical power to be provided to a portable electrical device connected to the power supply station.