1. In 1958, this airline was operating nonstop Vickers Viscount turboprop service between Miami and Havana with multiple daily flights. Identify the air carrier. And here's a hint: this same airline was operating Viscount service at this same time in association with BOAC twice a week between Nassau and Havana via an intermediate stop.
I guess this was Cubana. They bought fleets of both Viscount 700, and later Viscount 800, in the 1950s. As their market pretty much disappeared after the revolution, they were all sold off in the early 1960s.
17. In the spring of 1969, how many round trip flights a day was United operating with the Douglas DC-6 in its entire system?
I think the answer is one, operating Reno-Elko-Ely-Salt Lake City and return once a day, and this was the last mainstream piston operation by a US major carrier. One of those intermediate stops had a runway that wasn't suitable for jets, and in the end United subcontracted operation of this route, which in Regulation days they were not allowed to give up, to Frontier using Convair 580s.