Q: When I was a passenger in the 1940s and early 1950s, there would be a guy standing near each engine when starting up, holding what seemed to be the nozzle of a good-sized fire extinguisher on wheels. I’ve always wondered if it was really needed and when and why was this ultimately deemed unnecessary?
A: In the 1940s and 1950s, piston radial engines were the norm on aircraft—for both general aviation and commercial operations. Because of the design, oil has a tendency to pool in the lower cylinders of these engines. Usually, this creates a puff of blue smoke during engine start—but if there is too much oil, there is a chance of fire.
That was just part of the challenge. Starting a radial powerplant requires the engine to be primed, and that takes some skill.
