Beagle - driving West on the M4 yesterday we could see the procession of aircraft descending into Heathrow on the less common approach from the West. Mrs TTN (bless her) said "what if it's raining or foggy and they cant see the runway?" Cue long discourse on runway approach aids, which then led onto the question of alternate airfields, diversion fuel etc.
I must sit her down to read your post #69 !