| F | SK | SECTION F — MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING |
| F03 | KL | MACHINES OR ENGINES FOR LIQUIDS (for liquids and elastic fluids F01; positive-displacement machines for liquids F04); WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR |
| F03H | UKL | PRODUCING A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR (from combustion products F02K) |
| F03H 1/00 | HGR | Use of plasma to produce a reactive propulsive thrust (generating plasma H05H 1/00) |
| F03H 3/00 | HGR | Use of photons to produce a reactive propulsive thrust |
| F03H 5/00 | HGR | Producing a reactive propulsive thrust, not otherwise provided for |