It is a given that airport control towers should be as high up as possible, to provide a good vantage point.
However, the taller the tower, the easier it is for things to run into it; this is widely regarded as a Bad Thing. It's also more vulnerable to wind forces.
Engineers at BorgCo aviation
services have therefore designed the first hovering control tower.
The installation in its idle state is almost indistinguishable from a regular control tower on a sturdy concrete base. However, arranged around the top are eight ducted propellers, converting the gallery to a giant octacopter.
When operating, the propellers can lift the gallery high into the air, powered by electricity flowing through the two mutually redundant umbilicals from a spool in the base.
Positioning is provided by a redundant array of scanning lasers using ground reflectors as datum points, backed up by DGPS.
Should a motor fail, the gallery has sufficient excess lift to execute a controlled safe descent - even with two adjacent motors stopped.
Standby generators and batteries in the tower base guard against external supply failure. Should even this fail, the umbillicals can be severed from the gallery by explosive cutters and dry-charged primary batteries provide enough hover duration for a controlled soft landing.
Should an errant aircraft approach the gallery, it can duck or dodge as required to avoid contact.
The gallery can move horizontally and vertically within the limits of the umbilical, to provide the staff with the optimal view for any given situation.