92 certain regulatory standards. ASTM International’s F3322-22 Standard Specification for Small Unmanned Aircraft System parachutes, released in 2018, defines requirements on designing, manufacturing and testing them for the uncrewed aerial space. That standard is arguably the most important and rigorous for parachutes in this industry, and it requires pushing products to their limits in 40-50 different tests, simulating a wide variety of failures, but ensuring any system passing all of them is output as a highly mature recovery solution. However, like many UAV components, parachutes themselves cannot be certified. Systems are only certified with platforms, so UAV manufacturers or operators must work with parachute suppliers to gain ASTM certification, as and when that becomes mission-critical. Mobile launch and recovery Over the course of this publication we have seen a handful of UGV and USV systems that could carry VTOL-capable UAVs, and serve as their takeoff and landing platforms. However, numerous defence and commercial organisations are taking increasing interest in ways to launch and recover fixed-wing, non-VTOL UAVs on moving vehicles – not only on road vehicles, but also on trains, crewed aircraft and non-carrier vessels with a latent capacity for facilitating valuable uncrewed survey, logistics or emergency response missions. In such use-cases, both current and proposed, having VTOL UAVs land on moving platforms is frequently unfeasible due to the highly complex aerodynamics involved, so a mobile launch-andrecovery solution for relatively stable fixed-wing drones is the preferred option for many. One well-known method for airborne release and recovery of fixed-wing UAVs involves using a multirotor aircraft to lift UAVs into the air as a payload, mechanically release them once their engines are at cruising power, and later catch them with a carried recovery hook or tether, potentially at varying distances from the original deployment location. That multirotor solution is built with considerable hardware redundancy, with potentially up to 16 rotors, although much of the software tuning needed to perform this sort of launch and recovery must be embedded in and tailored to the fixed-wing aircraft at the heart of the mission. The former aircraft must track key timing and altitude stepping points through its internal clock, while the latter must track altitude as well as the activities and attitudes of the former in order to pace its sequences for engine startup, and for release into free, fixed-wing flight. Hence, significant custom work is needed for the system to work from one UAV to the next, although the system gives enormous advantages in transportability due to it being more collapsible than ground infrastructure, and it also remains far superior than most VTOL-transitioning UAVs in terms of gust and wind rejection when near ground level. Another approach to mobile launch and recovery – designed particularly for integration on delivery vans, military vehicles and more – consists of an electromechanical sandwich of two horizontal plates, each holding arrays of soft-tipped, telescopic, stainless-steel pins, such that a UAV can fly into the horizontal space between those pins before the plates are actuated to close about the UAV and hold it gently but securely in place. The pins are electromechanically controlled and tightly monitored to avoid crushing or snapping anything sensitive on the UAV, such as antennas (they have been proven in tests to be able to hold an egg without breaking it), through sensors and the UAV optionally communicating details on its architecture. The pins typically complete their movements within less than a second to avoid generating turbulence. Prior to that, this launch-and-recovery device senses the incoming UAV, and localises it relative to its own position with sub-millimetre accuracy while broadcasting that localisation information to the UAV in real time. The UAV, meanwhile, uses a softwarebased, wraparound layer about its flight controller in order to use that information, and by fusing it with GNSS and inertial data it adjusts its position to within 2 cm accuracy as it comes in for recovery. Using this approach, the UAV can be recovered at speeds of over 60 mph December/January 2025 | Uncrewed Systems Technology ASTM International’s F3322-22 standard defines requirements on designing, manufacturing and testing parachutes for small UAVs (Image courtesy of ParaZero)
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