Aerial ziplines stretched from terrain or towers can replace ground-based runways and associated airport sprawl. Airports of the future could co-exist directly over other land uses. Take-off and landing from ziplines would potentially be safer and more reliable in many cases. Complex, heavy, and expensive landing gear on aircraft might be replaced by a simple clip-on snatch-block stub. Current airport wingspan limits can be raised, allowing far higher L/D transports. Deceleration could be as positive as an aircraft carrier's arrestor cables, or dependably gentle. Steep climb-out and approach trajectories would be supportable. Capital cost compared to graded and paved runways should be minimal.

 

Highly repeatable towed-launches, and tethered aviation generally, look favored by zipline methods. Hot energy kiteplanes could operate in large numbers by such launching and landing means; no E-VTOL needed. A low-altitude fixed zipline can support towing to high altitude.

 

The possible variations are an open adventure of aeronautical imagination. Ropeway logging carriages and other cableways have already operated at about 100 km per hour historically, at the lower range of take-off and landing speeds for high-performance aircraft of many kinds. Aerial refueling operations are a partial flight-control model, comparable in difficulty with potential operations from ziplines.