London Airport is Now "World's Safest".The R.A.F. Take Over -- The control officer of the G.C.A. apparatus "talking a plane down" during the first tests now being held at London Airport. The arrival of an R.A.F. crew at London Airport to man the newly installed G.C.A. (Ground Control Approach) apparatus completes the installation of the last of the safety landing aids at Britain's No.1 airport, and will make it the safest airport for landings in the world. G.C.A. was widely used by the R.A.F. during the war. Under the system, a control officer on the ground, using a radar screen, "talks" and aircraft down on the runway in any weather. April 23, 1947. (Photo by Fox Photos).