The AIR-SPADE patented supersonic nozzle turns compressed air into a high speed, laser-like jet moving at twice the speed of sound, Mach 2. All of the energy and momentum of this air moving at approximately 1200 mph is focused onto the soil dislodging it in a fraction of a second. Soil is an unconsolidated assemblage of solid particles that may or may not contain organic matter, the voids between the particles being occupied by air and/or water. The aggregate nature of soil aids the ability of the air to fracture it; while stronger materials and ones that are not porous like metal or plastic pipes or cables or even wooden tree roots are unaffected.
Although exhaust nozzles for rocket engines have been designed and built for many years, supersonic air jet excavation nozzles are different. AIR-SPADE has carried out extensive research into the aerodynamic design of its earth excavation nozzles. AIR-SPADE has developed its own nozzle design, which is protected by U.S. patents. Unlike propulsion nozzles, the energy to accelerate the air comes primarily from the release of its compression rather than from the combustion of a fuel. Because of their small size, particular attention must be paid to the effect of the boundary layer on the nozzle profile. Special tooling and computer-aided-machining is used to manufacture the nozzles. AIR-SPADE continues to refine and improve its design through detailed mathematical modeling and laboratory experimentation.