Porcelain
A hard, white, translucent ceramic material that was used as the insulator in some of the early aircraft spark plugs.
Aviation Maintenance Technician Handbook — Powerplant, p. G-21
A hard, white, translucent ceramic material that was used as the insulator in some of the early aircraft spark plugs.
Aviation Maintenance Technician Handbook — Powerplant, p. G-21