The present invention provides a method for charging control in a Flow Based Charging system, which includes the steps of: a Charging Rule Function receives a charging rule request message from a Traffic Plane Function, the CRF sends a charging rule to the TPF. The system includes a first rotor hub assembly and a second rotor hub assembly spaced apart from the first hub assembly and carried by the fuselage. In addition, the apparatus includes a first compartment thermally coupled to the at least one heat pipe. The error signal is fed back to the transversal filter so as to control the transversal filter such that the error signal becomes minimum. The road service includes swapping the vehicle with a new vehicle.