Aerospace, Military & Defence Focus


Connector specification for never-fail systems


By Ryan Smart, vice president of product, Harwin A


ustrian engineering firm visionair specializes in developing high-reliability (hi-rel) power management systems (PMS) for UAVs


(unmanned aerial vehicles) – primarily for the defence sector. Particularly renowned for its fail-safe power management systems, it boasts a never-fail design philosophy, where systems are developed, engineered, and tested to be robust and dependable across every eventuality. In this case study, we’ll examine how the company’s philosophy is implemented in relation to connector specification in its mission-critical subsystems.


Modern UAVs, particularly in defence applications, have evolved into complex integrated systems with advanced sensing, communications, and control capabilities. At the same time, the need for extended flight times and payload efficiency demands smaller, lighter airframes, driving miniaturization in every subsystem.


In this context, connectors are a crucial design constraint. All the onboard electronic systems – from cameras, LiDAR modules, and inertial measurement units to power distribution, flight control, and communications systems – need to reliably exchange both power and data within a confined, weight-limited space. For instance, in all of visionair’s products, such as their Engine Starter, Power Distribution Units and Generator Control Unit, connectors must endure the punishing, high-vibration environment onboard a UAV airframe while reliably handling intense power spikes during e.g. engine cranking – especially during cold weather starts. This influences the design of the interconnect architecture, because connectors directly affect weight, reliability, and system resilience.


Connectors are therefore a critical design choice within such systems. Be it for a 2,000 W power distribution unit, or a battery monitoring board, the wrong selection decisions can lead to the addition of


24 September 2026


Left: visionair’s electronic engine starter incorporates Harwin connectors for reliable power and signal transmission in demanding aerospace environments.


unnecessary weight, reduce signal integrity, or impact vibration resistance. The below will explore how connector design influences UAV performance in demanding environments – and examine how visionair works with hi-rel connector manufacturer Harwin to address these requirements and embed its connectors across critical subsystems throughout its PMS and UAV platforms.


Operating environment The harsh conditions in which UAV components must operate are quite distinct from those of terrestrial electronic systems, and this contributes to long-term reliability challenges. UAV subsystems must endure aerodynamic turbulence and continuous high-vibration environments, particularly near propulsion systems. UAVs are subject to extreme swings of temperature, from searing desert heat to extremely low temperatures at high altitude operation, with rapid fluctuations causing expansion and contraction of materials, further stressing solder joints and mechanical interfaces. And depending on where they are deployed, UAVs may have to cope with dust, sand, or moisture.


“For interconnects, real-world conditions can include persistent mechanical stress and repeated micro-movements, as well as dynamic and shock loads – and temperatures that can exceed typical engine bay specs,” says Ben Tschida, CEO at visionair. “Components may have to operate beyond specifications in some conditions, meaning we have to test thoroughly – and connectors must be evaluated not only on their nominal


Components in Electronics


electrical ratings, but on their mechanical and electrical stability


under vibration, shock, and environmental exposure, overloading the system to a certain extent of its ratings.”


Risks and consequences


Persistent vibration at contact interfaces can result in progressive loosening of connections or fretting corrosion. And even though it may not immediately present as a total system failure, it can quickly manifest as intermittent signal loss and compromise mission data from UAVs used for mapping, surveillance, or tactical operations.


Transient shock loads are also common, where abrupt impacts during, for instance, hard landings or recovery operations can expose connectors to sudden accelerations, and this makes robust mechanical retention a critical design consideration for maintaining contact integrity and avoiding interruptions in power or signal paths.


UAVs designed for military can cost hundreds of thousands of dollars. And with the consequences of system failure including the potential loss of the aircraft, component reliability is directly linked to mission and financial risk. “Connector reliability is a critical consideration in our system design,” says Ben. “We can’t take the risk of going for a cheaper connector – it just has to work.”


Connector specifications


The environmental, mechanical, and electrical challenges described influence connector design choices in UAV development. So too


Figure 1: “Connector reliability is a critical consid- eration in our system design. We can’t take the risk of going for a cheaper connector – it just has to work,” explains Ben Tschida from visionair.


does size, weight, power and cost (SWaP-C) constraints. As such, proven experience in the aerospace and defence sectors is critical when selecting a connector family, and these need to be specifically engineered for high- reliability environments – with certification to globally-recognized standards, such as EN9100D/AS9100D.


Over the last decade, visionair design engineers have specified Harwin connectors across multiple core PMS subsystems, including its generator control unit (GCU), power distribution unit (PDU), engine starter, battery monitoring board, and 250W power supply.


Several technical and practical reasons have influenced visionair’s choices. This includes form factor, with rectangular connectors offering multiple benefits over circular devices: increased pin density, better mounting and cabling options, lower cost, greater design flexibility, and superior ease of handling. This form factor also improves modularity and customizability, allowing integration of power, signal, and data. Similarly, features such as single, double, and triple-row configurations, and fixing options including jackscrews (J-Tek), latches (L-Tek), and bayonet-style fast-mating hardware (101Lok) have also proved vital.


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