When Carlo was two years old, I drew two circles and an egg on a piece of paper. “Circle” and “egg”. When kids are two years old, it’s important that you stick to two-syllable words.
I asked him to point out which one was different. He pointed to the egg.
“Good,” I said. “ The others are circles, and this one is an …?”
“Po-ta-to,” he said.
Oh well, he was always ahead of his time.
S-turns across the road are barely touched on, if not skipped, in primary flight training. A pity, since ground reference manoeuvres are more fun than golf or sex.
Actually, I don’t do golf, so I could be wrong. About golf.
Ground reference manoeuvres punch home an advanced, esoteric skill – flying by looking out the window.
Fledgling pilots think flying is punching buttons on the autopilot (now gender-neutered as “Flight Management Computer”), staring with glazed eyes at glass screens inside the cockpit.
The truth is brutal: Nearly all general aviation flying, from primary training to ascension to heaven, is visual.
And unless you are an airline pilot rated for full-coupled Cat III instrument approaches in zero-zero weather at London Heathrow, you can only land by looking out the window.
Pilots who don’t look out the window will never learn to fly even just straight and level. Nor will they ever spot the Red Baron coming out of the sun, Spandaus spitting fire. Heck, the Red Baron didn’t even have cockpit windows!
Day before Fathers Day. On the ground, mechanics and pilots leaned against a 19-knot surface wind.
To their credit, Clark Aviation and Omni Aviation students were challenging the wind with touch and gos.
PAL Aviation School pilots, grounded when the wind exceeds 12 knots, were probably doing touch and gos with FHM magazines in their barracks.
Airborne over Charlie Four, Carlo lined up on the arrow-straight road from Magalang to Mexico (the town in Central Luzon, not el pais de Speedy Gonzalez). The wind came “from somewhere on the right”. His brief was to fly a perfect circle.
You can’t ignore wind in a light airplane. If you go into a shallow bank to the left, the wind pushes you out.
You belatedly tighten the turn by banking steeper, and maybe resort to the age-old tactic of cheating with a little more left rudder . . . .
. . . But that’s the worst thing to do, because you should shallow your bank instead as you fight back into the wind. Otherwise, you end up with a “9” instead of a “O”.
Carlo kicked off a 45-degree steep turn (this is where neophytes and airline pilots start feeling their stomachs, and coffee cups slop over in airline cabins), quickly bringing the airplane around in a half circle, before the wind could screw him up.
Then he shallowed his bank as the airplane’s nose swept from north to west to south.
This is his GPS track.
He rolled to the right for an opposing turn, and chuckling turned to dismay as he drew a potato!
He was not tight enough at the start, and too tight at the end. He never got back to the road.
The key is is look at the ground, imagine the desired track, and fly the airplane over that visualized track, constantly adjusting bank angle to tack and flow with the wind.
Now thoroughly intrigued, Carlo went into a more challenging series of S-turns, stitching the road with identical radii intestines . . . .
. . . Then zipping the stitches shut with a straight run to the southeast, crabbing into the wind just enough to track exactly on the road.
You can’t do this with navigational instruments. Even if there were navaids in the area, VORs and beacons are simply too imprecise to keep your track within a few feet of your desired course.
Only the human eyeball, and a brain, can do this.
I had my own shot at it. Like Father, like Son — I screwed up my own second 360-degree turn.
I was happier with my S-turns, tight and symmetrical. I reviewed these GPS tracks at home, and when I saw my track over the road I really felt good.
My inbound (blue) and outbound (yellow) tracks were nearly identical. All I had done in flight was to crank in a wind correction angle that kept the road at the same place on my windshield.
A student of maneuvering flight need only spend 30 minutes on this on a windy day to understand the key concepts of what heading to take to true up a course line, and how to track that course in wind.
What’s the point, you ask?
Well, any visual pattern is a ground reference maneuver. Think about the mess we make flying downwind and turns to base and final as we ignore the wind.
You’d be surprised by how many pilot candidates go into panel interviews for airline job openings, then get bushwacked by the very first question:
"Tell me the difference between Heading, Course and Track."
Posted from Manila, July 7, 2009