World War II forced countries to pour massive amounts of money and manpower into achieving full control over
link the skies. The result was
link a crop of airplanes from America, England, Germany, Italy, and Japan that refined and debuted technology we still use today: Variable pitch propellers, enclosed cockpits, lighter and stronger alloys, retractable landing gear, and
link pressurized cabins. The first jet-powered airplane came from this era, as well.