Final answer:
EVA Wi-Fi is generally available throughout the flight, with possible restrictions during takeoff and landing. It is offered to all classes of service, depending on the aircraft and flight route.
Step-by-step explanation:
The availability of EVA Wi-Fi depends on several factors and it is generally provided throughout the flight. However, there might be exact restrictions based on the flight phase or technical limitations. For instance, passengers might be asked to turn off electronic devices or disconnect from Wi-Fi during takeoff and landing for safety reasons. Once the aircraft reaches cruising altitude, the service typically becomes available. Moreover, Wi-Fi availability can also depend on the particular aircraft, as not all planes may be equipped with the necessary technology. It is not limited to any specific class of service, so passengers in both business class and economy can access the Wi-Fi where available.
Note that for the most accurate and up-to-date information, passengers should check with EVA Air directly or consult their flight information since policies and services can change.