120.4
Think yourself lucky CX don't operate 777-200 a/c in LHR.
CX SOP's require us to be gear down flaps AT 30 by 1500' AGL. And then on Vref +5 and spun up by 1000' AGL. There is no way in hell we could give you 170 to 5 or even 160 to 4. Even the 777-300 using CX SOP's would be tough.
Watch out for companies that have tight SOP's like ours, it will give you a headache.
And pray CX don't send the 300ER to LHR in the next few years, although I'd love to fly into LHR again.
cheers