Archive · Prior art · PA-001
King, 1967
The architecture appeared before the enabling hardware.
In 1964 a North Carolina inventor filed a patent for an aircraft with no propeller and no jet. King proposed to ionize the air around the craft, then drive that conductive air with a traveling magnetic field produced by rings of increasing diameter stacked along the body. The moving field would induce eddy currents in the ionized air by mutual induction; by Lenz's law those currents oppose the field's motion, so the air would be driven along with the field and the craft would feel the reaction. Steering came from dividing the ionizer ring into independently controllable arcuate segments, so that ionization, and with it thrust, could be varied quadrant by quadrant.
King identified a class of atmospheric electromagnetic propulsion architecture: ionized gas, magnetic interaction, distributed momentum transfer, sectored control. That makes the patent valuable conceptual prior art. It is not experimental proof of aircraft-scale performance, and the patent reports no measurement of thrust, power or efficiency. Nothing in it establishes that this mechanism, or any other, is the correct high-efficiency architecture.
What King proposed
A vertically oriented craft. At the top, an ionizer ring, in its simplest form a ring of spikes held at a large potential difference, to ionize the surrounding air. Along the body, driving rings, which King specified as superconducting, fed with polyphase current so that the point of maximum flux sweeps from the leading end to the trailing end. A permeable pole piece on the axis to raise the flux density. Below, a conical skirt directing the driven air downward and outward. For steering, the ionizer divided into controllable arcuate sectors, and optionally switchable closed coils in the skirt that absorb power locally when shorted. King also noted that in a naturally conductive medium such as sea water the ionizer could be dispensed with, and he cited an earlier British proposal (GB 830,816, 1960) that used superconducting rings with ionization means.
What the patent does not answer
It does not say how much conductivity a spike ionizer can sustain in sea-level air, or at what power. It does not estimate the eddy-current force that conductivity would support, the Joule heating that would accompany it, or the fraction of electrical input that would reach the air as directed momentum. The stability argument is a static force diagram at two attitudes, not a dynamic analysis. These are not criticisms of a 1964 filing; they are the questions that remain open. They are, almost line for line, the gates of the XR-1 test program.
What changed since 1967
| Capability | 1964 | Now |
|---|---|---|
| Superconducting magnets | Niobium-based conductors at liquid-helium temperature | REBCO coated conductor; a large-bore magnet has held 20 T (MIT and CFS, 2021) |
| High-frequency power electronics | Rotating machines, tubes, early thyristors | Silicon-carbide and gallium-nitride converters at megawatt scale |
| Microwave sources | The gyrotron was just being invented | Megawatt-class gyrotrons running for a thousand seconds (ITER) |
| Plasma diagnostics | Largely qualitative | Interferometry, Thomson scattering, emission spectroscopy, fast probes |
| Computational plasma physics and CFD | Hand analysis and equivalent circuits | Coupled multifluid plasma, chemistry, field and flow solvers |
| Materials | Aircraft alloys, early composites | Ceramics, composites and coatings for plasma-facing, high-heat-flux surfaces |
| Electrical machines | Low specific power | High-specific-power generators developed for electrified aircraft (NASA) |
| Digital control | Analog and relay logic | FPGA-rate inner loops and real-time estimation of plasma state (TCV, 2022) |
None of these advances is evidence that King's craft, or XR-1, would fly. Each one makes a specific measurement possible that was not practical in 1967: conductivity per watt in sea-level air, force with field and current reversals, the momentum in the wake, and the efficiency that connects them.
King does not answer whether the architecture works at aircraft scale. He establishes that the question is old. Modern hardware makes it possible to ask the question much better.
US 3,322,374 expired long ago; the physics it describes is public. Lorentz Aerospace has no connection to the inventor or his assignees and claims none.