The Ca.101 was a small trimotor used mainly by the Italian air force. I-ABCQ flew with a company from Milan, La Voce del Cielo (The Voice from Heaven), with four large loudspeakers mounted downward in the cabin and driven by four underwing generators. Patented by the Plane Speaker Co from the USA, the system was reportedly quite effective from altitudes of 3000 to 4000 feet. Whether used for Fascist propaganda or not, the aircraft is probably seen here during a July 1933 visit to the Netherlands where Verkade biscuits were advertised from the sky. Photo from: Nationaal Archief (Netherlands)

The fifth and final prototype in a line that led to the production Gloster Gauntlet. By the time the SS.19B flew in July 1933 over four years had passed since the first Bristol Jupiter powered aircraft. Despite the Mercury powered J9125 being close to production standard it would be a further 17 months before the first production aircraft was flown. Gloster photo. Photo from: Civil Aviation Historical Society, Melbourne, Australia