108 Developed by ISS Aerospace in Chieveley, Berkshire, in England’s Thames Valley, the Sensus L is a modular heavy-lift multicopter built to handle demanding, data-intensive tasks in a variety of industries. Initially created to tackle oil giant Total’s METIS programme for the deployment of thousands of wireless geophones for 4D seismic survey work in Papua New Guinea, the vehicle has since won customers in defence, energy, environmental management, and logistics. Bracketed by the Sensus Nano with a maximum take-off weight (MTOW) of 1 kg, and the 600 kg Heavy Lift UAS Sensus MX8 under development for the UK MoD, Sensus L is positioned in the middle of the company’s line-up, with MTOW figures of 24 kg for the Sensus L4 and 38 kg for the Sensus L8, which are variants of the same basic airframe with 4 and 8 rotors respectively. “Its design allows for mounting of up to three large payloads, making it effective for comprehensive data collection and meaningful analysis during a single mission,” according to CEO Ryan Kempley. Sensus L features what the company describes as a unique central payload interface as well as front and rear payload support rails with a total carrying capacity of up to 18 kg. “This makes it especially suited for complex, multi-sensor data fusion tasks requiring real-time processing,” Kempley notes. He explains that in developing a vehicle with these capabilities, the company’s engineers faced challenges related to its structural integrity, particularly in the hull of the airframe, the mounting of payloads particularly as far as weight and balance are concerned. Further, integrating the ISS Unified Avionics Architecture into a larger platform required careful tuning. “As the system is modular, and designed to be agnostic to payloads, much work was put into the data in/out connections available at the payload areas,” Kempley says. These challenges drove iterative refinements, resulting in a system now in its fourth development phase, with over 9000 flight hours logged across the Sensus range. Each phase enhanced hull rigidity, power systems, and performance. Materials, structure and stealth Additive manufacturing is fundamental to the construction of the Sensus UAS range. The core hull consists of 3D-printed nylon reinforced with carbon fibre strands, with key components further strengthened using continuous carbon fibre, glass fibre, or Kevlar. The Sensus L alone incorporates over 190 3D-printed parts, while high-wear and stress-prone areas are CNC-machined from aerospace-grade aluminium. The Sensus range features a common frame structure made from these composite materials. The fusion of 3D printing and carbon fibre reinforcement creates a strong yet lightweight structure, ensuring durability in demanding missions. The printed material offers aluminium-like strength at a fraction of the weight, allowing for enhanced resilience without compromising efficiency, Kempley notes. A variety of metals including aluminium, titanium, and marine-grade A4 stainless steel are also used for specific components and fittings. For example, custom 7068 aluminium pressure spreaders secure the main boom fixings, while A4 stainless steel bolts provide Peter Donaldson examines a heavy-lift multicopter built to support data-intensive payloads Stealthy modularity April/May 2025 | Uncrewed Systems Technology
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