public async Task <IActionResult> Models(int manufacturerId)
        {
            ListAircraftViewModel model          = new ListAircraftViewModel();
            List <Model>          aircraftModels = await _models.GetModelsAsync(manufacturerId);

            model.SetModels(aircraftModels);
            return(PartialView(model));
        }
        public async Task <IActionResult> Index(int manufacturerId = 0, int modelId = 0)
        {
            // Construct the model and assign the selected manufacturer and aircraft
            // model
            ListAircraftViewModel model = new ListAircraftViewModel();

            model.ManufacturerId = manufacturerId;
            model.ModelId        = modelId;

            // Load the manufacturer list
            List <Manufacturer> manufacturers = await _manufacturers.GetManufacturersAsync();

            model.SetManufacturers(manufacturers);

            return(View(model));
        }