🛡️🧲 The Magnets Inside the World's Most Advanced Warplanes — And Why They Are America's Biggest Vulnerability Look at that F-35 diagram carefully. Four control surfaces labelled: Trailing Edge Flap. Aileron. Rudder. Horizontal Tail. Every single one of them moves via an Electrohydrostatic Actuator (EHA) driven by a rare earth permanent magnet brushless DC motor. This is not a minor component. This is primary flight control. Without it, the aircraft cannot fly. 🧵👇 ✈️ HOW AN EHA ACTUALLY WORKS — AND WHERE THE MAGNET IS The F-35 was a watershed moment in aviation history — it replaced traditional centralised hydraulic systems with fully distributed Electrohydrostatic Actuators. Each EHA sits directly at the control surface it drives — at the rudder, at the aileron, at the horizontal tail, at the trailing edge flap. When the pilot or fly-by-wire computer sends a command: 1️⃣ A rare earth permanent magnet brushless DC motor inside the EHA receives electrical power 2️⃣ The motor spins a local hydraulic pump at precise speed — no central hydraulic lines running the length of the aircraft 3️⃣ The pump pressurises a self-contained fluid circuit 4️⃣ That pressure drives a hydraulic ram that physically deflects the control surface 5️⃣ The surface moves. The aircraft turns. The magnet is the first mover in this entire chain. Remove it — or degrade it — and the surface doesn't move. The aircraft loses control authority. The magnet is the first mover in this entire chain. Remove it — or degrade it — and the surface doesn't move. The aircraft loses control authority. 🧲 WHICH MAGNETS. WHICH RARE EARTHS. Two magnet classes dominate airframe actuation: 🔷 NdFeB (Neodymium-Iron-Boron) — highest power density of any permanent magnet class. Used in EHA motors throughout the F-35's primary flight control system. Requires Nd, Pr, Dy, Tb. Heavy rare earths — specifically dysprosium — are added at grain boundaries via GBD (grain boundary diffusion) to maintain coercivity at the elevated temperatures inside an operating actuator motor. 🔷 SmCo (Samarium-Cobalt) — used where temperatures are extreme — turbomachinery, engine-mounted generators, aerospace actuators operating near exhaust or hot-section bleed air. Superior thermal stability above 150°C. Requires Sm and Co. The F-35 uses both. NdFeB across primary flight control EHAs. SmCo in the Honeywell turbomachine — the engine-mounted starter/generator that provides electrical power to every system on the aircraft. ⚠️ THE INCIDENT THAT PROVES THE VULNERABILITY IS REAL — NOT THEORETICAL In September 2022, the Pentagon suspended all F-35 deliveries. Not due to a design flaw. Not due to a software problem. Not due to enemy action. Due to a single SmCo magnet in the Honeywell turbomachine — one component — that was found to contain cobalt-samarium alloy sourced from China, in violation of DFARS. Lockheed Martin confirmed: "A magnet in the F-35's Honeywell-made turbomachine was recently discovered to have been made with cobalt and samarium alloy that came from China." Deliveries of the most advanced fighter aircraft in history — halted. Over one magnet. Weighing a few hundred grams. The investigation found Chinese-sourced material had passed through multiple supplier tiers before anyone detected it. This is not a hypothetical supply chain risk. It already happened. The U.S. Air Force grounded delivery of its frontline fighter over rare earth provenance. This is precisely why DFARS 252.225-7052 goes into full statutory effect January 1, 2027 — and why every tier of the defence supply chain must now trace rare earth origin from mine to finished component. 🚀 THE B-2 SPIRIT — BUILT TO EVADE RADAR, CONSTRAINED BY THE PERIODIC TABLE The B-2 Spirit stealth bomber is a different architecture — no vertical tail surfaces at all. Every directional control comes from differential thrust and split drag rudders embedded in the flying wing. But the magnet dependency is, if anything, deeper. The B-2's entire survivability rests on: Radar-absorbent structural materials incorporating rare earth compounds Actuators driving the split drag rudders and elevons — the only flight control surfaces on the aircraft APQ-181 phased-array radar — radar travelling wave tubes using rare earth magnets to focus microwave energy Thermal barrier coatings on hot section turbine components — yttria-stabilised zirconia requiring yttrium The EWI DoD assessment states it directly: "Actuators for flight control surfaces of aircraft, including flaps, rudder, and ailerons" — and "Thermal barrier coatings (yttria-stabilized zirconia) in 'hot' sections of jet engines." A B-2 without a functioning rare earth supply chain is a B-2 that cannot be manufactured, maintained, or repaired at operational tempo. 🌍 THE SUPPLY CHAIN GEOMETRY UNDERNEATH BOTH AIRCRAFT China controls ~90%+ of rare earth oxide-to-metal conversion and ~90–94% of global permanent magnet production. Every NdFeB and SmCo magnet installed in an F-35 EHA or B-2 actuator traces back — unless explicitly verified otherwise — through a supply chain that runs through Chinese processing. The 2022 F-35 magnet halt proved the verification fails in practice. The DFARS deadline mandates it cannot fail after January 2027. The rare earth elements powering these actuators: Nd + Pr → motor magnetic flux generation Dy + Tb → high-temperature coercivity retention (grain boundary diffusion) Sm + Co → turbomachine thermal stability Y → thermal barrier coatings on jet engine hot sections Every single one: China controls the separation and metallization of all of them at commercial scale today. 🔑 WHY THE ACTUATOR IS THE CRITICAL NODE — NOT THE AIRFRAME Rare Earth Exchanges put it precisely: "Modern warfare is increasingly constrained not by weapons design but by the availability of materials. A precision-strike campaign can burn through munitions faster than supply chains can replenish them. And those supply chains hinge on components measured not in tons — but in grams of dysprosium." The F-35 diagram at the top of this post shows four labelled control surfaces. Each one moves via an EHA. Each EHA has a permanent magnet motor at its core. Approximately 900 lbs of NdFeB and SmCo magnets are embedded across a single F-35 airframe. 900 lbs of magnets. One halted delivery programme. Seven rare earth elements. One country controls the processing of all of them. The flight control system is only as sovereign as the magnets inside it. And those magnets are only as sovereign as the rare earth supply chain that produced them. 🧲⚙️ MAGNETS IN DEFENSE: THE HIDDEN HARDWARE BEHIND MODERN WEAPONS Everywhere you look in today’s battlefield there is software and guidance code. But none of it moves a fin, steers a bomb or shapes a radar beam without magnets. Rare-earth magnets. 🎯 ACTUATORS — WHERE SOFTWARE MEETS AERODYNAMICS Precision‑guided munitions: • Cruise missiles and SLAM‑class weapons use samarium‑cobalt / NdFeB motors in mid‑body fin actuators to turn guidance commands into hard G‑loads on target. • JDAM tail kits bolt NdFeB‑based actuators onto “dumb” bombs (GBU‑29/30/31/32/35/38), turning gravity bombs into GPS‑guided PGMs. • GPS‑aided munitions like the GBU‑36/37 bunker‑busters rely on rare‑earth tail kits for course correction all the way to impact.👇 Further reading here 👇 xitter.cf/roblun1/status/2040375… 🇬🇧🇦🇺🇺🇸🧲✈️ 📌 Attach: F-35 control surface actuator diagram (provided below) 📌 Attach: TAAC Flight Control Actuators YouTube Video 📌 Attach: Inside The World's Most Powerful Stealth Bomber YouTube Video Sources: Van den Hurk Critical Minerals Analysis Metal Tech News 2025 · USAF B-2 Fact Sheet roblun1 | X ✈️#RareEarths #F35 #B2Spirit #StealthBomber #PermanentMagnets #NdFeB #SmCo #FlightControl #EHA #ElectroHydrostaticActuator #Dysprosium #Terbium #Samarium #CriticalMinerals #DFARS #NationalSecurity #DefenceSupplyChain #WesternSupplyChain #MagnetActuators #AerospaceDefence #ChineseMagnets #SupplyChainSecurity #Lockheed #F35JointStrikeFighter #Honeywell #IXR #IonicRareEarths #IonicTechnologies #MagnetRecycling #AdvancedMagnetLab #DLA 🛡️🧲✈️🇺🇸