Excellent service from LCY, I took it a number of times. Actually an Airbus 318. A 737 is not permitted to fly from LCY. The 318, smallest of the family, didn't have the range to reach JFK, with reserve fuel, hence had to refuel in Shannon, thus the stop, and US immigration. Due to upper atmosphere winds, came back non stop. It was supported, financially, by some major City organisations, but Covid put an end to that. As I recall, flight no was BA001! Only 32 (or36) seats, all business, flat beds. In my experience, never full!