Given how many airlines of the day referred to their prop jets as "jets", what I should have asked was...
What was the world’s first airline to operate a non-propeller equipped passenger jet with a flight deck designed for just two crew? What kind of jet was it?
I must be missing something here because I would have thought the answer was the same.
As Helene Hanff (New York City) wrote to Frank Dole (London) : "I guess that doesn't mean over there what it means over here".
The Jet Viscount had two Rolls-Royce Tay jet engines; nothing to do with the Tay that appeared a generation later on the Fokker F100 etc. It was really a Vickers development project, quite early in the Viscount development, and was lent to BEA for some London to Paris scheduled flights. If any of you haven't seen it (or even heard of it) before, here it is. Like the previous Jet Viking, these flights all took place before the Comet 1 went into scheduled service.
https://www.google.co.uk/search?q=je...HZk9RW6nP94%3D