public ActionResult <FlightPlan> Post(object json)
        {
            FlightPlan serializedJson = JsonConvert.DeserializeObject <FlightPlan>(json.ToString());
            FlightPlan flightPlan     = _service.AddFlightPlan(serializedJson);

            if (flightPlan == null)
            {
                return(NotFound());
            }

            return(Ok(flightPlan));
        }