There is of course the other 'internal aids' approach as demonstrated by Puddy Catt one day when recovering his Hunter (no internal aids apart from DME) to Brawdy in typical low cloud conditions. When told by ATC that the colour state was Y2 and asked what type of instrument recovery he would like, responded in his inimitable fashion 'the weather's far too bad for an instrument recovery dear boy, I shall be recovering visually'.