I think that few people today have any idea of how little was out there to navigate from in those days. Were not many federally made maps, so road maps were used. If you knew which railroad track to follow, that was great because it was much easier to follow from the air. ( Hence the “I follow Railroads” definition of IFR which is the joking reply of the non IFR rated pilots response of, Do you have an IFR rating. )
On an overcast night out west there are still a lot of places you are just ‘in the dark’ and not having an instrument rating can be fatal. It was 100 times as bad in the early airmail days.
A compass works great except that the wind is constantly pushing you off your course. If I fly due North according to the compass but there’s a stiff wind from the East I’ll actually be flying NW. If I’m just using a compass I’d have no way to know I was tracking off course.
If you have an accurate forecast of the wind you can correct for it when you calculate your heading, but that’s not always the case. Having waypoints on the ground helps you determine if that forecast was accurate or not, and if not how to correct it.
And, to add to the joys of trying to fly by dead reckoning:
Winds aloft are not necessarily the same at all altitudes.
If you keep in mind the huge premium weight costs (in WWII, the primary trainer plane did NOT have radios - they weighted a bunch and the fresh pilot-to-be didn’t need the distraction).
Space, electrical power and additional lift was found as soon as those first “A-N” beacons came along.
A-N: the Morse code for A is dot-dash; N is dash-dot. If you were flying E-W, your route was between a beacon to your north and one to your south. You listened to the A-N frequency and found the spot where dot-dash and dash-dot joined to produce a continuous tone.
You could only navigate by flying directly towards or away from a beacon. In that sense (and only that sense) it was vaguely similar to NDB or VOR.
If you’re familiar with VOR, it’s very crudely conceptually like a VOR that only had 4 “radials”, each 90 degrees wide. Those were called “quadrants”. They were each a bit wider than 90 degrees and hence overlapped a bit. This created a set of four distinct 5- or 10 degree-wide “beams” at very roughly 90 degree angles. Each station was confiugured differently, and the 4 beams might be 70 or 110 degrees apart, but couldn’t be too much farther off 90 degrees than that.
By listening to the sound of the broadcast, you could identify which quadrant you were in. You’d then fly tangential to the station until flying into the side of a “beam”. Which you also identified by sound. The goal was to drive into the side of a “beam” and then turn towards or away from the beacon then steer by ear to remain more or less centered in the “beam” as you tracked towards or away from the beacon.
And much like VOR, you navigated a long distance by flying a beam outbound from a station near the departure airport until getting close enough to the next station to listen for, and then connect to, one of it’s beams to follow inbound to that next station, change course over the station to a different beam and follow it outbound towards the next station, lather rinse repeat.
It was really radio-assisted dead reckoning. You really had to know where you were to begin with, and not get lost along the way. Once disoriented, getting reoriented to an AN range was a bear and took many minutes.
Here’s a corner of the 1940 sectional chart; by then such 1:500000 charts covered the whole country.
See all those red stars, each with a number, morse code and a pair of arrows? At the left edge of the chart, beacon 21 is roughly 210 statute miles from the west end of the beacon airway (Salt Lake). The arrows point to the next beacon; beacon 23 is roughly 230 miles from Salt Lake. Along with the rotating white beacon on a tower, there were other lights to give the morse code for the last digit of the light number – the beacons themselves all look the same.
In the daytime the concrete arrows pointed to the next beacon, and it seems there was some sort of light to try to do the same at night.
The lights came first, in the 1920s, then the A/N radio ranges in the 1930s. One great advantage of the VORs that started appearing 1950ish was that the V stood for Very High Frequency, much more reliable than the kilocycle radio ranges. Lots of VORs are still in use; if you look up their lat-lons on airnav.com you can see them on the online aerial pics.
Still lots of beacons on 1950s charts, and probably a few in the early 1960s. A few of the beacons on this 1946 1:250000 chart were carefully surveyed and you can still get those lat-lons from NGS.
I actually made those charts for about 10 years. I remember looking for them after this thread and there were a few still charted because they can still be seen. I should go see if there are any left now, though I no longer work in that section.
Not realizing this was a zombie, & having just been barnstorming in Ohio a couple of weeks ago I was going to waste a lot of time on that linked site. Alas, it’s gone the way of the dodo in the last 10 years.
