imagine it's your job to guide airplanes to land, in bad weather (they can do it themselves in good weather) on this motorbike!

 read the 1940 article on good books at https://books.google.com/books?id=Kh1_ojeiiawC&pg=PA100&lpg=PA100&dq=Shell+Aviation+Lew+Screwbird&source=bl&ots=Q_j3QR-6hr&sig=ACfU3U0mB5rzlvJZ9-M9coh1SoIG4CWDhw&hl=en&sa=X&ved=2ahUKEwi-xcLmoLL2AhXcJUQIHSnyCVwQ6AF6BAhxEAM#v=onepage&q&f=false