starring James Cagney. Principal aerial photography took place near North Bay, Ontario with CF-AYO carrying temporary registration "CF-HGO." CF-AYO was lost in a crash in Algonquin Park in 1952. Its wreckage currently is on display at the Canadian Bushplane Heritage Centre. Almost immediately, the Norseman proved itself to be a rugged, reliable workhorse with steady sales. The first aircraft, CF-AYO, was designated the Norseman Mk I. The next aircraft, "CF-BAU," having some minor changes required after the certification tests, and a new Pratt & Whitney R-1340 Wasp SC-1 engine up-rated from 420 to 450 hp, was designated Norseman Mk II while the next three aircraft were Norseman Mk IIIs: "CF-AZA" going to MacKenzie Air Service, Edmonton, Alberta, "CF-AZE" to Prospector Airways, Clarkson, Ontario and "CF-AZS" to Starrat Airways, Hudson, Ontario. "CF-BAU" would be modified on June 26, 1937 to become the prototype Norseman Mk IV, powered by a Pratt & Whitney Wasp S3H-1. The Mk IV became the "definitive" model but the production run might have ended at a few hundred examples if not for the advent of the Second World War. Second World War Until 1940, the Noorduyn company had sold only 17 aircraft in total, primarily to commercial operators in Canada's north and to the Royal Canadian Mounted Police. With the outbreak of war in Europe, demand for a utility transport led to major military orders. The Royal Canadian Air Force and the United States Army Air Forces became the two largest operators; the RCAF ordered 38 Norseman Mk IVWs for radio and navigational training for the Commonwealth Air Training Plan. USAAF Colonel Bernt Balchen had been involved in establishing a staging route across Greenland to facilitate the ferrying of aircraft from North America to Europe. He required a bush plane rugged enough to survive in the harsh conditions of the Arctic. After evaluating six Norsemans diverted from a previous RCAF order, late in 1941, he recommended the purchase of the Norseman Mk IV specially modified to USAAF requirements as the YC-64A. After the US entry into the Second World War, the USAAF placed the first of several orders for a production version C-64A Norseman. The principal differences involved fitting two fuselage belly tanks bringing the standard fuel capacity to ; an additional cabin fuel tank of 32 Imp. gal (145 L) could also be installed. These changes resulted in an increase of in the loaded weight of