1.6 m 3D‑printed precooler concept
LEAP 71 showcased a large, metal 3D‑printed precooler concept about 1.6 meters tall intended to cool inlet air for hypersonic engines. The design targets Mach 5+ inlet conditions to avoid thermal choke in sustained high‑speed propulsion concepts (x.com).
A precooler is a heat exchanger for air rushing into an engine so fast that compression alone can make it glow-hot. LEAP 71 and Farsoon said on November 12, 2025, they built a metal demonstrator about 1.5 meters tall to show that kind of cooling hardware can now be printed at very large scale. (leap71.com) In a hypersonic engine, the intake squeezes incoming air before combustion, and that squeeze drives temperatures up sharply. The European Space Agency said Reaction Engines tested a precooler at airflow temperatures equivalent to Mach 5 in 2019, underscoring how central rapid cooling is to any air-breathing system at those speeds. (esa.int) LEAP 71 said its printed unit was designed for hydrogen-cooled, combined-cycle propulsion, which means an engine that breathes air in the atmosphere and switches operating modes as speed rises. The company said the part was produced with Farsoon on an FS811M-U-8 metal powder-bed-fusion machine, a large-format printer with build volume above 1.5 meters in each dimension. (leap71.com 1) (leap71.com 2) The engineering problem is not just heat but airflow. A 2023 study in *Applied Thermal Engineering* modeled a hypersonic intake-precooler system at Mach 5.0, 3.5, and 2.0 and found that heat transfer and inlet performance are tightly coupled, meaning the cooler has to remove heat without choking the engine’s breathing path. (sciencedirect.com) LEAP 71 said its software-generated geometry uses a “fractal folding” layout to pack more cooling surface into a compact volume. In plain terms, that means more metal area for hot air and cryogenic fuel to exchange heat across, while keeping separate flow paths inside one printed structure. (3dprint.com) That geometry is why additive manufacturing matters here. Traditional machining struggles with dense internal channels and intertwined passages, while powder-bed fusion can build those passages layer by layer inside a single metal part. (leap71.com) The larger aerospace pitch is runway-to-orbit flight without dropping stages, often called single-stage-to-orbit. LEAP 71 and several trade publications framed the printed precooler as hardware for that class of vehicle, where atmospheric oxygen could be used for part of the climb before switching fully to rocket propulsion. (leap71.com) (tctmagazine.com) The caveat is that this is still a concept demonstrator, not a flight-qualified engine component. LEAP 71 announced a manufactured part and exhibition display at Formnext 2025 in Frankfurt, but it did not announce integrated engine testing, intake testing, or flight tests for the precooler itself. (leap71.com) (3dprint.com) So the immediate story is less about a vehicle ready to fly than about what can now be fabricated. A meter-scale metal precooler with dense internal passages is the kind of part hypersonic concepts have long needed and manufacturers have long struggled to make. (leap71.com) (esa.int)
