Both were tested, and the results are related in Design of a one-third scale multi-tethered aerostat system for precise positioning of a radio telescope receiver.
Page 6:
Two different variable lift aerostats, the Skydoc and Helikite were considered. Both are shown in Figure 5. The smaller aerostat on top is the Skydoc aerostat. It is an oblate (flattened) spheroid and its mesh flying harness gives it a pitched orientation which allows its hull to generate lift in a wind field.The lower aerostat is the Helikite and it is a combination of a spheroid aerostat and a kite. It generates lift using its delta wing. The attraction of such aerostats is their ability to maintain a more vertical orientation in high winds. For a conventional aerostat, only the drag increases as the wind speed increases and, as a result, the aerostat loses altitude as the angle of the aerostat tether becomes less and less vertical. To evaluate the performance of the two variable-lift aerostats, experimental tests were performed while towing the aerostats behind a boat. During the tests, poor performance of both aerostats was observed. At high speeds between 40 and 50 km/hr, the aerostats became unstable, and sometimes dove violently all the way to the water surface. Based on these observations it was decided to exclude the variable-lift aerostats from further analysis and instead focus on more conventional spherical and streamlined types.
(2) (PDF) Design of a one-third scale multi-tethered aerostat system for precise positioning of a radio telescope receiver. Available from: https://www.researchgate.net/publication/228560180_Design_of_a_one-third_scale_multi-tethered_aerostat_system_for_precise_positioning_of_a_radio_telescope_receiver [accessed Oct 17 2024].
“At high speeds between 40 and 50 km/hr, the aerostats became unstable, and sometimes dove violently all the way to the water surface. Based on these observations it was decided to exclude the variable-lift aerostats from further analysis and instead focus on more conventional spherical and streamlined types.”
The least we can say is that it is not very encouraging to operate a wind turbine permanently in the air under these kytoons.