During the course of building my RV-9A I became curious about the history of the flush rivet (and there are lots of them in the RV-9A airframe). By chance, I happened across a book ?What Engineers Know and How They Know It ? Analytical Studies from Aeronautical History? by Walter G. Vincenti. Chapter 6 provides such a history, it is titled ?Design and Production: The Innovation of Flush Riveting in American airplanes, 1930-1950?. The need for flush riveting resulted from the increasing speeds of aluminum airplanes during this period. Vincenti traces the development of the flush rivet through the pioneering companies of the Hall Aluminum Aircraft Corporation, Douglas Aircraft, Northrop Aircraft, Bell Aircraft, Curtiss-Wright Corporation, with the assistance of NACA. Interestingly, the now standard 100 degree head angle was not a given, early rivets ranged from 78 degrees to 130 degrees. Tooling for machine countersinking and dimpling had to be invented, and extensive testing had to be done to guarantee the strength of flush riveted joints. New rivet sets and compression riveters had to be invented. The chapter has an extensive bibliography of 61 references for further reading.
Of the eight chapters in the book, several others may be of interest to RV builders. Chapter 3 is about the development of flying qualities requirements from 1918 to 1943 and Chapter 5 is about air propeller tests 1916 to 1926.
Of the eight chapters in the book, several others may be of interest to RV builders. Chapter 3 is about the development of flying qualities requirements from 1918 to 1943 and Chapter 5 is about air propeller tests 1916 to 1926.