Volz Volz Servos GmbH & Co. Kg Volz The propellers are designed for flight in the low air densities of the stratosphere, so they have coarser pitches than most UAV props. Tyler comments that handlaunching the Zephyr to glide on its wings is necessary partly because launching it using propeller torque alone would be quite time-consuming, as it is not optimised for ground-level air densities. At cruising heights, they are run at about 2000 rpm; near the ground they spin at just 500-600 rpm. Briggs notes that finding a carbon composite manufacturer capable of the geometric tolerances, stiffnesses and various other parameters needed for the props was extremely challenging. “The process of manufacturing them is complex, and once they’re delivered you need to test every propeller to make sure they all perfectly match each other in performance,” he says. Launch Confidence of a successful launching depends not only on tests in the factory and at launch sites, but also on preparatory steps such as in-depth meteorological checks aided by radiosondes. “If we see something huge like a hurricane in a test flight’s area, we’ll leave and return in a couple of days – but obviously, we’re not going to consider taking away someone’s connectivity service when they need it most,” Tyler says. “Flying above hurricanes will be key for that, so we’re working on some updates for slightly reduced weight, higher battery energy density and higher continuous altitudes.” Two Z8 airframes can fit side by side in a standard 40 ft shipping container (each disassembled into a specialised holding frame designed in-house) that can be couriered to most locations around the world. “The avionics and most of the subsystems will already be in the wings before loading the containers,” Briggs adds. “We’ll also ship our containerised ground station and usually another container full of spare parts and key ground support equipment.” Once on site, the various components are unpacked, and the GCS, rovers and cells for testing and battery conditioning are connected to power. Although often dubbed a ‘solar-powered aircraft’, Tyler quips that since the Zephyr’s batteries are pre-charged using grid power, it is more accurate to call it ‘almost entirely’ solar-powered. Once charged, the batteries are installed in the main wings and dihedrals, and the aircraft is bolted together. Tyler estimates that the HAPS will sit on the runway for an hour of pre-flight checks and orientation to face into the wind as much as possible. Underneath the wings are several handles for five launch personnel to grip and hoist the aircraft. Once the motors are spinning, the crew takes around AALTO Zephyr 8 | Dossier A special frame holds two disassembled Zephyr 8 airframes side by side and fits inside a standard 40 ft shipping container for straightforward transport to a launch site You already know us, but what about our EASA certified subsidiary? AIRCRAFT ELECTRONIC ENGINEERING DEVELOPS, QUALIFIES, CERTIFIES, PRODUCES AND MAINTAINS CUSTOMER-SPECIFIC SYSTEMS AND DEVICES Reliability for progress aee-gmbh.de www.aee-gmbh.de
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