In 1911, H.H. Bales presents a patent for an airplane powered by a gunpowder-type solid-rocket engine titled: "Pyrotechnical propelling Auxiliary Mechanism for Aerostructures."

"First patent part"

-As shown, the rocket engine is a cylinder with a bottleneck forming a Laval type venturi to increase the gas velocity.

-We can see the solid fuel with a conical hole for getting a greater combustion surface and gas generation.

-The patent's project used nine of these engines in a cluster as we can see in the patent diagrams below.

“Details of the next two patent pages”

From Appendix 11: This is Haden Herbert Bales of Ashcroft, British Columbia, Canada. The patent is registered at the United States Patent Office, dated September 11, 1911.