I have a thing for maps. (I might have mentioned this once or twice before…) So finding a collection of old air navigation maps on the internet is a serious delight – one I’m not about to keep for myself.
The collection covers about 70 maps from the Connecticut State Library at Hartford, and are an incomplete set of ‘United States Air Navigation Maps (Experimental)’ from 1923–24 with revisions up until about 1935. There’s a full list below.
Note: To preserve some of the detail, the map images I’ve included with this article are LARGE – at least 1MB each – so click with intent.
A huge boost
These maps date from the formative days of regular air services across the United States, following the first survey of a transcontinental mail route in early August of 1920 – when 100 letters were flown from Hazelhurst Field on Long Island to Durant Field in Oakland, CA by Harold “Slim” Lewis.
The initial route options were surveyed by a small fleet of three Junkers-Larsen JL-6s, American versions of the fantastically modern Junkers F.13 – an all metal, cantilever monoplane which had first flown in Germany in June 1919. The second and third aircraft were piloted by Mons Emil and renowned aviator Bert Acosta.
Five years later, when the maps were first being produced, the 1925 Kelly Act gave the US aviation industry a huge boost by legislating that the air mail be carried by private contractors.
This was possibly the most pivotal act (and Act) in the history of American commercial aviation.
At a stroke, it made flying a viable business opportunity. The first Contract Air Mail (CAM) carrier was Ford Air Services, operating Ford-built Stout 2-ATs (a single Liberty-engined predecessor of the Ford Trimotor, and the original “Tin Goose”) on routes between Detroit and Chicago, and between Detroit and Cleveland.
The pinnacles of public enthusiasm
This set an early precedent for the nepotistic aviation holding companies that would grow into giant airplane, engine, airline and air mail monopolies before they were forcibly broken up by the Air Mail Act of 1934. Among the most memorable of these were Bill Boeing’s United Air Services, which gave us United Air Lines and Boeing; along with General Motors’ General Aviation Division which would give the world North American Aviation.
One notable pilot who also benefited from the commercialisation of air mail was a young flying instructor from St. Louis, MO, named Charles Lindbergh. In October 1925, he was hired by the Robertson Aircraft Corporation to pioneer and fly the 278-mile CAM-2 between St.Louis and Chicago.
Eighteen months later his solo Atlantic flight would lift aviation to the pinnacles of public enthusiasm.
“…nor gloom of night…”
Meanwhile, our maps were being developed by the Army Corps of Engineers, under direction from the Army Air Corps, to provide aviators – and the mail pilots in particular – with the added safety of clearly defined routes to follow.
But flying on a clear, sunny day is one thing. The Post Office Department’s unofficial creed that “Neither snow nor rain nor heat nor gloom of night” should prevent the “swift completion of their appointed rounds” meant that night-flying also needed to be made more reliable.
And so, in 1923, Congress funded a transcontinental series of navigation aids – including large concrete arrows for “contact” (i.e. visual) flying during the day, coupled with a chain of light towers that pilots could follow at night. This airway was built up quickly, starting with a stretch between Chicago, IL and Cheyenne, WO on the basis that pilots could leave either coast in the morning and reach their lighted track by nightfall.
Night mail flights started on July 1st, 1924 and cut the coast to coast delivery time by two full days. The complete airway, stretching from New York to San Francisco was operational by mid-1925, and by 1927 a 4,000 mile network of lighted routes was in place. Eventually, the network would mark 18,000 miles of air routes with 1,500 beacons.
Windows in time
With a civil air route on one side and the corresponding Air Corps Map on the other, these beautiful charts cover that entire, formative period of air navigation, air mail and airlines. The rapidly expanding network of lighted beacons are a major feature along keys routes – as are the magnetic tracks to fly and the conveniently spaced emergency landing grounds that were also part of the system.
It’s interesting to follow the routes and compare them with modern IFR maps. In some cases, the direct route has always been the best. In others, 1920s pilots would have threaded their way through mountain passes that commercial pilots could hardly pick out from the Flight Levels today.
Some maps, like No.32 Phoenix to San Diego, include a black and white relief for easier night navigation.
Case-bound in linen board, the originals must be a joy to behold. Each chart was designed to be held and used in an open cockpit, probably while wearing bulky fur-lined leather gloves and being bucked around by the weather – and possibly while holding a flashlight with your teeth.
And while they were simply tools of the trade in their day, these maps are now more precious as works of art – or as windows in time.
Remember, they come from the days when “IFR” really did stand for “I Follow Railways/Roads” so each one also carefully lays out all the roads, rail lines and city boundaries of the time. It makes them a fascinating snapshot of the US when the railway was king – before intercity flights, internet, or even interstate highways. It doesn’t take a whole lot of imagination to start adding little people…
I should probably say that these maps are NOT to be used for actual navigational purposes. (D’uh!) But there’s nothing to stop you exploring their nostalgic charm in your preferred flight simulator. Perhaps you’ll even set the weather to “filthy” and make your own trans-continental mail run in a Boeing Model 40. That’s what I’ll be doing… Enjoy!
You can read more about the US Air Mail beacon system here. (I highly recommend it.)
The complete maps:
You can use these links to download the full maps for your neck of the woods – or any other necks you’d like to “fly”:
No.34 Elko, NV to Reno, NV
No.110 St.Louis, MO to Chicago, IL
No.111 Chicago, IL to Milwaukee, WI
No.119 Buffalo, NY to Albany, NY
No.131 Pueblo, CO to Cheyenne, WO
No.133 Las Vegas, NV to Milford, UT
No.136 Boise, ID to Pasco, WA
No.137 Portland, OR to Spokane, WA
No.139 Pocatello, ID to Butte, MT
No.150 Kansas City, MO to Omaha, NE
If you hit any dead links, please let me know and I’ll fix them right up.