A boring day of ODO led to some curiosity-based research into the history of air navigation. I saw these strange beacon-like objects in a museum a while back, and I think this article explains how they were used.
http://www.centennialofflight.gov/essay/Government_Role/navigation/POL13.htm
Executive summary: the USPS's ancestors led the push to have pilots flying at night (back in the days A4's was just getting interested in flying machines). Since unaided pilotage is difficult, and dead-reckoning requires wind-corrections based on pilotage, Post Office air fields started using rotating beacons to identify the landing strip, as well as a solid light pointing toward the next field in the journey (creating the effect of an airway). These beacons were only visible to about 40 miles, so they started using intermediate beacons (sometimes in the form of fires) every 10 miles along the path. The beacon towers had painted numbers for daytime use, and sequenced flashing for night use. The next logical upgrade was the incorporation of radio transmission, which was the birth of a radio-based airway, which is a different story altogether.
http://en.wikipedia.org/wiki/Airway_(aviation)
This article attests that airways were invented to keep civilian pilots out of military airspace. The first radio navaids transmitted Morse code, and later a steady frequency, to aid pilots in staying on course. This time also saw the birth of airborne 2-way radio transmitters (stemming from the need for PIREPs). At some point after WWII, VOR was developed and popularized, and the rest is history.
I apologize if any of this info is inaccurate, as it is a summary of several hours of time-accelleration. I'm hoping that someone who actually flew around using these legacy navaids can chime in with a few amusing anecdotes.
http://www.centennialofflight.gov/essay/Government_Role/navigation/POL13.htm
Executive summary: the USPS's ancestors led the push to have pilots flying at night (back in the days A4's was just getting interested in flying machines). Since unaided pilotage is difficult, and dead-reckoning requires wind-corrections based on pilotage, Post Office air fields started using rotating beacons to identify the landing strip, as well as a solid light pointing toward the next field in the journey (creating the effect of an airway). These beacons were only visible to about 40 miles, so they started using intermediate beacons (sometimes in the form of fires) every 10 miles along the path. The beacon towers had painted numbers for daytime use, and sequenced flashing for night use. The next logical upgrade was the incorporation of radio transmission, which was the birth of a radio-based airway, which is a different story altogether.
http://en.wikipedia.org/wiki/Airway_(aviation)
This article attests that airways were invented to keep civilian pilots out of military airspace. The first radio navaids transmitted Morse code, and later a steady frequency, to aid pilots in staying on course. This time also saw the birth of airborne 2-way radio transmitters (stemming from the need for PIREPs). At some point after WWII, VOR was developed and popularized, and the rest is history.
I apologize if any of this info is inaccurate, as it is a summary of several hours of time-accelleration. I'm hoping that someone who actually flew around using these legacy navaids can chime in with a few amusing anecdotes.