Sir, Clare Harbord (letter, Sept 4) claims that an extra runway at Heathrow would provide sufficient capacity until 2040, and that this would match Amsterdam and Paris.
What she fails to mention is that those airfields have surplus capacity in the form of more than three runways. A three-runway Heathrow operating close to capacity would result in even greater disruption when there were delays caused by fog or incidents that temporarily closed a runway. A modern international airport needs a spare runway that can be brought into operation at short notice. Without this, delays and cancellations are inevitable every time that anything disrupts the perfect flow of air traffic.
Captain Will Steynor (British Airways, retired)
South Brent, Devon