Patent attributes
An unmanned aircraft such as a tethered drone has an electrical power connection for receiving electrical power from a remote source, and a power delivery system for delivering electrical power to onboard applications equipment such as radio transmitters. To ensure that ground staff are not exposed to high levels of radiation from the transmitters, power is only delivered to the communications equipment after the aircraft has left the ground. A sensor associated with the aircraft's undercarriage may be used to detect when the aircraft is airborne. The applications equipment is powered from an accumulator which is only charged up from the power supply after launch. In the event of a failure of the power supply when airborne, the output of the accumulator is diverted to control propulsion and flight control systems, which are normally powered directly from the power supply, to allow a controlled descent, and thus shutting off the applications equipment before the aircraft returns to proximity to personnel on the ground.
