The son of a Royal Air Force test pilot, Ashley was born in West Germany and began racing in 1966 when he took a course at the Jim Russell Racing School. He was fast but rather erratic and soon became known as "Crashley". He began to calm down more when he reached Formula 5000 in 1972 and was a front-runner in 1973, winning the European Championship event at the Jyllandsring. In 1974 he finished third in the series and made his Formula 1 debut with Frank Williams in 1974. He ran the Token Formula 1 challenger later that year but was back with Williams for the 1975 German Grand Prix but suffered serious leg injuries when he crashed the car. After an abortive time with a Stanley-BRM in 1976 he made his return with an Obex Oil-sponsored Hesketh but wrecked the car in a spectacular backward flip during practice for the 1977 Canadian Grand Prix at Mosport Park. He later built a career as a pilot of executive jets in the United States.