Block test of an airplane engine with propeller attached, showing the screen protection given to the mechanician. The necessity for this precaution Is at once obvious when It Is known that the propeller revolves at a speed of 1,400 revolutions per minute from the manual ' Practical aviation for military airmen ' by James Andrew White, Publication date 1918 Publisher New York, Wireless press, inc

---

Size: 3027px × 4129px
Location: USA
Photo credit: © Historic Illustrations / Alamy / Afripics
License: Royalty Free
Model Released: No

Keywords: ..., aeronautics, aeroplane, air, aircraft, airman, airmen, airplane, airplanes, american, army, aviation, aviator, aviators, battle, bi-plane, biplane, book, early, engine, fighter, fighters, flight, flights, force, group, historic, historical, history, idr, machine, mechanic, mechanical, mechanics, military, monoplane, picture, pioneering, plane, practice, students, teach, teaching, technological, technology, text, textbook, training, usa, war, warfare