(1914)Automatic Gyro-stabilizer: Keeps planes flying in a straight line which lead to auto pilot. (1930)Turbo Jet Engine: Enabled bigger planes that carried more passengers, giving more options for plane designs. (1933)Boeing 242: The first model airliner. could carry 10 passengers in comfort. completely metal and twin engined. (1938) The boeing 307 Stratoline was the first fuly pressurized plane, allowing it to fly 6.096 km high. this helped planed avoid bad weather as it could fly above storm clouds. (1969)Boeing 747: a wide bodied commercial airline, the most successful airline ever made.