Good points on London airport expansion

From a reader's letter in the FT:

Aircraft take off and land into wind – this reduces the ground speed required for flight and the length of runway required. In the UK, 80 per cent of winds are westerly [i.e. blow from west to east), so at Heathrow, aircraft are predominately flying low and slow over Greater London to land on the two westerly runways.

Heathrow, like most airports, has a mandatory 3 degree glide slope approach which results in a descent of 300ft per mile on the ground. This means aircraft over the centre of our capital city are descending through 1,500ft over our most populated areas.

If we consider London to be a circle, the worst possible position for an airport is therefore in the 9 o’clock position – where we have inadvertently built our biggest airport. Far better to have these low and slow aircraft landing at airports in the 12 o’clock (Luton), 3 o’clock (Thames estuary) or 6 o’clock position (Gatwick) where their approaches will not affect such large areas of population.

Aircraft accident data show that the majority of incidents occur on the approach to land; when an aircraft is at its most vulnerable, low and slow...

If you think that through, then the 3 o'clock position is not ideal either; which goes for London City and a possible Thames estuary airport. For sure, aircraft climb far more steeply after take off (and then they always seem to veer off wildly to port or starboard, I sit in my back garden watching them) than they descend before landing, but the same general east-west rule applies; aircraft would still be banking steeply over the greater London area. I'm no expert on these matters, but AFAIAA, the second most dangerous part of air travel is the take-off bit, so better safe than sorry.