So how do you make this 350 ppp ??? I think you are confused !!!
No, you are the one who is confusing two different metrics.
PPP (
passengers per plane) isn't the same as
seats per plane (unless you are assuming that every arrival and departure has 100% of the seats filled, which clearly isn't going to happen). The mix of traffic and markets at Heathrow mean that a ratio of pax to seats (load factor) of 75% is more realistic, so that's what I've used.
The reason I have stated a max of 125+ mppa is because I cannot see the plane loadings beyond 260 ppp in a reasonable timescale.
OK - and your 260 passengers per plane (compared to the current average of just under 150) at 75% load factor gives an average aircraft seat size of
350, which was the figure I calculated too.
So we're in agreement on the maths, where we differ is that you think you can run a hub operation with 350-seat aircraft, whereas nobody else does.