helipad vs runway

helipad

noun
  • A small landing place for helicopters, denoted by a large "H". 

runway

noun
  • A section of land, usually paved, for airplanes to land on or take off from. 

  • A defined, narrow section of land or an artificial structure used for access. 

  • In javelin, long jump, and similar events: a short track along which athletes can accelerate themselves for their jumps or throws. 

  • A stream bed. 

  • Hence, the number of months that a startup company can operate by using up its cash reserves. 

  • The usual path taken by deer or other wild animals, such as from a forest to a water source. 

  • A narrow walkway (often on a platform) extending from a stage on which people walk, especially one used by models during fashion shows. 

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