Unpasable or Unpassable: How To spell?
The word Unpasable is misspelled against Unpassable, an adjective meaning "Impassable."
Unpassable has double "ss" is mispronounced as "s"Remember double 'SS' in between the strings unpa & able which should not be misspelled with single 'S'
Wrong Spelling:  unpa-s-able  Correct Spelling:  unpa-ss-able 
Explore spell check of Unpassable to spell without errors.