A method and apparatus is provided for communicating data over a ground power line between a vehicle and a ground terminal. In one example, a first power unit detects a signal indicating connection between the first power unit and a remote power unit. Responsive to detecting the signal, one or more modems associated with the first power unit automatically establish a data connection with one or more remote modems associated with the remote power unit. After establishing the connection between the one or more modems in the first power unit and the one or more modems in the remote power unit, the one or more modems in the first power unit exchange data with the one or more modems in the remote power unit over the power line. In one example, the first power unit may comprise an onboard power unit in a vehicle (e.g., aircraft) and the remote power unit may comprise a ground power unit. Alternatively, the first power unit may comprise a ground power unit and the remote power unit may comprise in a vehicle (e.g., aircraft).