N3N In the 1920's and 1930's the US Navy was required to build 10% of its aircraft. When the US Navy's dirigible program was discontinued, the Navy had all these aluminum stringers laying around. The story goes that an Admiral on an inspection trip stated "Use it to build airplanes." They did. Nine hundred, ninety-six of them. There is no wood or welds in the N3N. the N3N was used as a trainer from 1934 into the 1950's. During WWII the US Coast Guard operated 28 N3N's although most were on floats.