Amsterdan, Dublin, Geneva, Milan and NY are the only ones with more than 10,000 flights in the first half of this year. But as NY sees by far the most widebodies, I think we can easily say that NY has the most seats per day from the UK.
I have no absolute numbers though, but I hope this helps a bit.
Viscount724 From Switzerland, joined Oct 2006, 21481 posts, RR: 24 Reply 4, posted (1 year 7 months 3 weeks 2 days 14 hours ago) and read 2859 times:
Quoting woodentom (Thread starter): There must be some daily breakdown I would have thought. I guess New York or Paris must be top but with all the flights around the Uk it was something I had been wondering?
Overall in a day some cities must reach into the 1000's of seats
At a quick count there are currently about 35 daily flights from the UK to New York (JFK and EWR combined). Based on a rough guess of an average of 250 seats per flight, that's close to 9,000 seats a day in each direction.
PlymSpotter From Spain, joined Jun 2004, 11126 posts, RR: 63 Reply 5, posted (1 year 7 months 3 weeks 2 days 14 hours ago) and read 2788 times:
I wouldn't be surprised if Amsterdam was above New York. KLM has multiple daily frequencies to what, 15 UK airports, and then there are all the LCCs and BA flights from LGW/LHR/LCY, plus CityJet/AF. Say, at a guess, that's 100 daily flights in each direction with an average capacity of 100 people - that's 10,000 people and I'm probably being a bit conservative on the average seat count and frequency.
LHR is dominant. For example over 80 per cent of all those travelling between the UK and NYC used this airport. And NYC has over 2.4 times as many LHR passengers as the next largest city (DUB). It is therefore virtually certain that not only there are more passengers between the UK and NYC than any other international destination but that more seats were offered between NYC and the UK.
Using this site my hunch that the high frequencies to AMS could result in it offering the most seats from the UK appears to have have been correct. A quick add up brings me to a total of 6,251,342 passengers travelling between the UK and AMS during 2010 - many more than New York. I can't think of another combination of connecting and leisure passengers which could top that, not even Paris.