Stercase or Staircase: How To spell?

The word Stercase is misspelled against Staircase, a noun meaning "A flight of stairs with their supporting framework, casing, balusters, etc."

Word contains consecutive vowels 'AI' in between alphabets st & rcase is misspelled as 'E'
Wrong Spelling: st-e-rcase
Correct Spelling: st-ai-rcase
Explore spell check of Staircase to spell without errors.