Once again, I’m on assignment for Smithsonian Air & Space. My story this time: Write up my experiences in attempting to re-fly one third of the Woodrow Wilson Transcontinental Airway using nothing more than the original written instructions from the nearly 100-year-old Pilot’s Directions—a slim manual published by the Postal Department to help new pilots find their way across the country in a time before modern ariel navigation. A time, in fact, before aviation maps and charts. A time before radios. A time before the flashing airway beacons, strung out like pearls in the night, led the way.
Pilot’s Directionsis descriptive text of contact flying. Look for farmer Brown’s red barn north of town, then follow the river. Keep the small round lake to your left. Fly south one section line for every 25 west. Don’t mistake the Union Pacific railroad for the Pennsylvania Southern. That type of thing.
How much will the face of our country have changed from above in the past 100 years? Will it still be possible to navigate the wide-open spaces between Omaha and Salt Lake City using these century-old written directions? Can modern pilots even follow directions like these? I’m going to find out.
Lisa is lending me her ‘Coupe Warbler for the mission, as he’s equipped nearly identically to an airmail plane of the era. Which is to say he hardly has any equipment at all. Lending me her plane, provided, of course, that she gets to come along on the adventure. But Lisa’s presence isn’t just for fun. Her presence is key to the mission’s success. She’ll watch my track on her iPad and ensure that I do not get us so lost that we run out of gas or blunder into modern military or restricted airspace.
In the meantime, to get ready for the flight, I’ve been living in the past. I’ve read every book about the early airmail that I can get my paws on, trying to learn more about the men, their machines, and how they flew the mail at the dawn of practical aviation. I’m focused on the few brief years when the government ran the show, before farming out the entire system to contractors, giving birth to the modern airlines. I’ve learned that the pilots stuffed newspapers into their flight suits to keep from freezing in their open cockpit biplanes. That they used clotheslines for windsocks. That they sometimes landed in fields to ask farmers for directions.
And I’ve learned that they were not only bold, but smart. They experimented, pushing the envelope of aeronautical science.
Chief among these experimenters was air mail pilot Wesley Smith. It was this pilot, in fact, who was reported to have first taped a flat half-empty bottle of whiskey on the panel of his mail plane to help him keep his wings level in the clouds. Call it a First Gen attitude indicator. Apparently, many of the other pilots quickly adopted this technique. In fact, I had read about these proto-instruments in the past, and I encountered them again and again in my air mail research. Like many pilots, I took this legend as Gospel truth, and didn’t think much more about it, beyond admiring their spunk and ingenuity.
But in the midst of my research, I was reminded that Bob Hoover was famous during his air show days for pouring himself a glass of tea during barrel rolls.
So wait a second… Either liquid is true to the world of the plane, or true to the outside environment. But it can’t be both. Right? Or can it? Are the forces in a roll stronger than the forces in garden variety maneuvers? Could a half empty bottle of liquid reveal the horizon in gentle maneuvers? Help keep a plane level in fog and cloud? Or like tea, would it always be level to the floor of the plane? I’d be a pour aviation journalist if I didn’t find out the truth.
Did I say “pour?” Sorry, I meant to say “poor.”
Clearly, I needed discover the truth for myself, and set the record straight if, in fact, we’ve been deceived all these years…
“Bank right,” I tell Lisa, as I hold the half-empty bottle of Chivas Regal to the windscreen, “Now bank left.”
Sadly, the level of the whiskey stays parallel to the floor of the plane, the horizon snapping left and right, cartwheeling outside the windshield, beyond the straight line of brunt amber liquid in the bottle.
“Is it working?” asks Lisa.
“Sure,” I say, “but not like we’d hoped. Instead of showing me the horizon, it’s showing me the floor of the plane. No matter what you do, it stays level.” I sigh. I’m bummed. I’m not looking forward to writing up this Plane Tale. I feel like I’ve just been given the assignment to shoot the Easter Bunny dead in his tracks. Of all the aviation legends, the un-tested whiskey bottle was always my favorite for some reason.
Likewise, I’m sorry to report, hanging your pocket watch from the roof of the plane fails to show the angle of bank. The watch always hangs straight toward the floor, regardless of how the floor is angled in relation to the horizon outside the plane.
What’s up with this? Why does liquid level itself to the plane’s floor when the plane is canted crazily to one side? Why does a watch chain hang straight down to the plane’s floor when your eyes tell you that you could fall right out the door and plummet to your death below without even bouncing off the wing?
The answer comes down to the forces of flight. A plane in a turn is assaulted by a barrage of forces and factors: Centripetal force, the vertical component of lift, centrifugal force, weight, inertia, thrust, resultant load, g-forces, effective lift, aerodynamic axis, load factors… Here, a picture is worth a thousand words:
Image: Agostino De Marco
To be honest, I don’t know which of the myriad of forces holds the whiskey true to the plane rather than true to the horizon. It’s probably the interplay of all of them that effectively moves the forces of gravity in line with the floor of the plane, bursting our myths.
So that’s it. The legend is dead. You can’t use a half-empty bottle of whiskey to keep your wings level in the clouds. But surely, the first pilot who tried this nearly a century ago must have discovered that on the first flight. Why, then, do we have so many historians telling us that the whiskey bottle was basic equipment for air mail pilots? Was it sloppy research by a historian who was not a pilot? Did one historian write it up and the others, like lemmings, followed him over the cliff of error?
Perhaps, but I think that there’s something else at play.
The airmail was a dangerous job. A dangerous job at the dawn of Prohibition, which came into law within two years of the start of the airmail. Suddenly booze was forbidden for everyone, much less for government employees. Were the pilots simply having fun with their ground-pounder bosses? Flouting the liquor law under the guise of flying equipment?
We’ll never know, but it gets my vote. It has the flavor of truth to it.
But what the hell, in a salute to Smith and his colleagues, whatever their real motives, and to keep in the spirit of the early days of airmail, we installed a Smith Attitude Indicator in Warbler for our re-flying of the Air Mail route.
It won’t help keep our wings level, but taking spirits into the sky will sure keep our spirits up.