Before revision: "Planes Are Landing By Radio When Fog Hides The Field", February 1931, Popular Mechanics bottom-right of page A basic system, fully operative, was introduced in 1932 at Berlin-Tempelhof Central Airport (Germany) named LFF or "Lorenz beam" due its inventor, the C. Lorenz AG company.
After revision: "Planes Are Landing By Radio When Fog Hides The Field", February 1931, Popular Mechanics bottom-right of page A basic system, fully operative, was introduced in 1932 at Berlin-Tempelhof Central Airport (Germany) named LFF or "Lorenz beam" after its inventor, the C. Lorenz AG company.