A while ago I published a blog post about how the BOT (British Overseas Territories) cover such a large extent that there is always sunlight falling on them. This led me to think about whether this means that the UK still has the potential to have a global reach. I decided that the easiest way of quantifying that was with the presence of an airfield. Airfields allow huge amounts of resource to be deployed extremely quickly - far quicker than by sea.
A lot of the islands that make up the BOT are so small and/or rugged that they cannot have runways built on them. I thought that it would be quite interesting to see what the distances are from the airfields that are on British territories as the coverage certainly cannot be 100%. I wrote the following Python script to investigate this issue: it simply obtains a list of airfields and selects the ones that are on British, or BOT, land. Once it has compiled this list of points it buffers them to create a map of ranges.
The database of airfields is taken from OpenFlights.org and only needed one manual addition (as the Saint Helena Airport only opened a couple of years ago and is currently missing from the airport database on GitHub). This map that this script creates is shown below.
As is clear, the available airfields have a decent coverage between the longitudes of the Cayman Islands in the West and the British Indian Ocean Territory (BIOT) in the East. There is no coverage of the Pacific Ocean even though that is where the Pitcairn Islands are.