Why Seeing Stars Can Be More Cool Than GPS
I've got this thing for cool, non-electric technology: pocket watches that run on springs and gears, slide rules, carburetors.
Maybe that's why I took a shine to Bill Castlen's recent article in IFR magazine on Celestial Navigation. In many ways the underlying math isn't that different than what goes on inside the GPS units that guide most of us from A to B without much thinking. It's just that the process is so exposed when it's a person shooting the angles to the objects in the sky, a person looking up in the tables and a person doing all the calculations. The fact that it can be so accurate blows my mind.
Castlen delves a bit into the dark side, describing how Fred Noonan and Amelia Earhart would have had to work this system to find Howland Island in 1937. With only the sun to use by morning, they could have known accurately where they were east-west, but not so well north-south. They would have (probably) intentionally flown too far north and then run the north-south line trying to pick out tiny Howland Island from the shadows of cumulus clouds. Think about that the next time you're following the magenta line to your a fuel stop.
One bit I knew about celestial navigation, but had long forgotten, was how important it was to have a pretty good idea of where you are before you took your sightings. Dead reckoning is the first step and a foundation of this system. I pulled down my tattered copy of Guy Murchie's Song of the Sky and flipped to this passage: "[The navigator] must note any change of speed, direction, or any factor of temperature, altitude, or engine adjustment that might affect the speed. If he does not, he loses a clue to accurate reckoning -- which would be like a detective overlooking a bloodstain at the scene of a murder."
This kind of navigation took relentless awareness. And if there's one thing our GPS-easy world has cost us, I think it's awareness. Not that I have any urge to go fly NDB approaches to minimums in killer crosswinds again. But when I did, I was much more aware of the winds, and the weather and the terrain, than I am flying GPS approaches to those same airports today.
And while it's true that awareness could save your hide one day when all the pretty pixels go dark, I think there's a better reason to make the extra effort at least some of the time. It's just part of being more skilled at what you do. It's like what a friend and 20-year test pilot pointed out to me once about takeoffs. He asked if I noticed how almost every tricycle-gear airplane has a slight pitch-up the moment the wheels break the ground. This happens because the center of rotation moves from the wheels to the CG and that increases the arm of the elevator. It becomes slightly more effective, and the nose pitches up. Slightly.
I never noticed until he pointed it out to me. To be honest, I'm not sure I can detect it now. But I like searching for it even if it really doesn't matter. Call me a romantic, but there's a richness in a world where you bother to keep track of the little details around you; where every once in a while you have to remember to wind your watch.
- Read the Castlen article, "IFR by Sun and Stars," here on AVweb.
- Interested in more stories from IFR magazine? You can subscribe here.