This chart was donated by Capt. Bill Eastwood. It shows how things were back then. For the older pilots, it will trigger memories. Some of the younger pilots might be unfamiliar with range approaches. Each range station transmitted audio signals covering four quadrants. The pilot had to continuously listen to the signals through his headset. In two of the quadrants, he would hear a Morse "A". In the other two quadrants, he would hear a Morse "N". Adjacent quadrants overlapped to create 3-degree beams in which the signals would merge to provide a continuous tone. In order to stay "on the beam," the pilot had to listen carefully and make heading corrections to maintain the steady signal. This system was used for enroute navigation, as well as for instrument approaches. It was low frequency, so there could be plenty of static, often when you most needed to hear the signals.
Range approach to runway 4R
You can see the quadrants marked with "A" or "N".
Look at the bottom of the chart, on either side of the approach leg to what was runway 4R.
Today, 4R is farther east, beginning below the approach end of 25R.
Runways 7/25 L and R, and 1/19 L and R haven't been used as runways in years.
What's left of them is used for taxiways and parking areas.
The main instrument runway, 4R/22L, was 7,840'. The longest open runway was 8,190'.
In those days, it must have seemed like all one would ever need.
Then and now
Note: These charts were 8" x 10 1/2", larger than the Jeppesen approach plates we used in later years.