Yes, 125mppa terminal capacity between the main runways. This has nothing to do with a possible R3 and T6 (+ T7, T8 ?).
BAA's proposals for the additional terminal extensions (+ satellites) is in BAA's published documents including its annual CIPs and annual / half yearly results.
OK, enough of this nonsense.
Firstly, have a read of this from the 2012 BAA CIP (or Strategic Capital Business Plan, as it's now termed);
"Changing airline business models, most noticeably a shift in network strategies which has slowed the trend from smaller to larger aircraft. New aircraft have allowed airlines to achieve lower unit costs per seat with smaller planes. Airlines have also benefited from greater flexibility or shorter lead times in making capacity decisions. These changes have allowed network carriers to respond to the challenge of short haul low cost carriers and increased network competition. The need to maintain a viable network with a mix of short and long haul connections also slows the overall trend at Heathrow to switch from short haul to long haul flights. In the last couple of years, premium traffic has become a larger portion of many network airlines’ business also resulting in lower seat densities."
And the previous year's CIP points out that, over the last decade, the average seat size of aircraft using Heathrow has actually
decreased (to under 200 seats), and yet you want us to believe that it could grow to 350 seats per ATM (which would be necessary to achieve your 125 mppa in 480,000 movements).
Let's do some simple arithmetic.
Supposing, for the sake of argument, you were able to decant 50,000 A320 movements from LHR to Northolt, and replace every one of those with an A380. That would still only generate another 17m or so seats per year, bringing the average seat size per ATM up to about 235 (way short of your required 350) and the pax pa up from 70m to about 83m (assuming a 75% PLF).
So how are another 42m passengers on top of that figure (your 125m less my 83m) going to be accommodated on the two runways without any additional movements ?
Answers on a postcard, please.