sesquiplane Directory References Discover The Craziest Scam? Gregor MacGregor Creates His Own Country What’s the Difference Between Hispanic and Latino? Did Duchess Anastasia Survive Her Family’s Execution? ¡Viva México! 6 Lost Civilizations 7 of History's Most Notorious Serial Killers 8 of the World’s Most-Remote Islands Contents sesquiplane airplane Learn about this topic in these articles:biplanes In biplane…the lower) is called a sesquiplane. A few triplane designs proved successful during World War I; powered aircraft with four or more main lifting surfaces have never been more than curiosities.Read More