Doug I also do not quite understand how your contingency fuel is equal to 35 minutes holding. We have a set percentage contingency amount and then an amount called extra, which is 99% blank unless ops have a special requirement and used by the captain for circumstances like expected holding or weather.
The rest of the figures make absolute sense and thank you for posting them. Incidentally the 737 like for like, being a bit lighter, uses a bit less fuel than the Airbus family. The purchase price and residual value allegedly balance things out, although not always the maintenance costs according to companies that operate both side by side.
BOAC thanks for the clarification.