The aerodynamics of an airplane sometimes don't cooperate with the pilots desire to roll, and instead produce both yaw and roll. Contributing factors are aileron parasite drag, induced drag between the wings and changes in the roll rate itself;
Ten years of meticulous workmanship and a daughters dedication combined to result in a stellar example of a Sequoia Falco F.8L. Builder John Shipler enjoyed the fruits of his labor before his health declined, and his daughter Kris has continued to fly and maintain the airplane after his passing.