Mr. Mugabe
BA B777 landing flap is F25. F30 is used on limiting runways and on one or two other situations but F25 is the usual.
At risk of ruining the thread here are a few other realities. BA SOP into LHR on an ILS would be gear taken circa 2000', usually with F20. At 1500' landing flap and final speed reduction to comply with the ATC norm of 160kts to 4DME. The engines would be at idle thrust during that speed reduction and normally spooled up again by 1000'.
As we know in the case in question the aliens took over at 600' believing Gordon Brown was on board. They were in the employ of Al Queada.