air ship vs transship

air ship

verb
  • To transport (goods) by air. 

transship

verb
  • To transfer something from one vessel or conveyance to another for onward shipment. 

  • To be transferred from one vessel or conveyance to another for onward shipment. 

How often have the words air ship and transship occurred in a corpus of books? (source: Google Ngram Viewer )