A&P technician powerplant textbook

USA. 2011 — 1387 p.
The lack of efficient and practical powerplants has limited aircraft development
throughout history. For example, in 1483 Leonardo daVinci conceived a flying machine
he called the aerial screw. However, without a powerplant, the aerial screw was never
developed. In fact, the first patent for a heat engine was taken out in 1791 by John
Barber. Unfortunately, Barber’s engine was neither efficient nor practical. In 1860,
Etienne Lenoir of France built the first practical piston engine. Lenoir’s engine, which
employed a battery ignition system and used natural gas for fuel, operated industrial
machinery such as lathes. The next major breakthrough in piston engine development
came in 1876 when Dr. August Otto developed the four-stroke, five-event cycle. The
Otto cycle is still used in most modern reciprocating aircraft engines.