The character Jett Stetson played by David Cade appeared in a total of 12 episodes throughout season 2,3 and 4.
Season 2:
Welcome Back Big Time Rush
Big Time Sneakers
Big Time Pranks
Green Time Rush
Big Time ChristmasSeason 3:
Big Time Double Date
Big Time Surprise
Big Time Camping
Big Time RescueSeason 4:
Big Time Scandal
Big Time Pranks II
Big Time Dreams