ui image won't load anything but array

im basically trying to get the UI image to populate specific aircraft, heres what I have, but I can't seem to get the UI image to let me insert anything but the array:

`@IBAction func displayPressed(_ sender: Any) {
        
        externalPicture.image = UIImage (named: externalArray [1])
        seatingSetup.image = UIImage (named: seatingArray ["\(forPicture())" + "seating"])
     
    }
    
    
    func forPicture() -> String {
        
        var aircraftFullName = ""
        let manuf = aircraftType.selectedRow(inComponent: 0)
        let model = aircraftType.selectedRow(inComponent: 1)
        if manuf < aircraft.count {
            aircraftFullName = aircraft[manuf]
            if let aircraftModels =  models[aircraftFullName] {
                if model < aircraftModels.count {
                    aircraftFullName = aircraftFullName  + " " + aircraftModels[model]
                }
            }
        }
        selectedAircraft.text = aircraftFullName
        
        if aircraftFullName != "0" {}
        return "\(aircraftFullName)"
        
    }


    
    let aircraft = ["Airbus", "Boeing", "Bombardier", "Embraer"]
    var models = [ "Airbus": ["A300", "A320", "A330", "A340", "A350", "A380"], "Boeing": ["B737", "B747", "B757", "767", "777", "787"], "Bombardier": ["CRJ200", "CRJ700/900"], "Embraer": ["ERJ145", "ERJ170", "ERJ190"] ]
    
    var externalArray = ["320outside", "747outside"]
    var seatingArray = ["AirbusA320seating", "BoeingB747seating"]`