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Old School Navigation, a Flying Junkyard, and Mom

by Scott Kinney

in Aviation Blog, Aviation Stories

Meet N5636A – a 1956 Cessna 172A.   She was one of the first Cessna 172s to come off of the production lines in Wichita, Kansas.  She’s the 636th Cessna 172 to be produced, to be exact.

Her engine’s a Continental O-300; a six-cylinder, 145hp engine with a pedigree dating back to the late 1940s.  It runs surprisingly smoothly for an engine that’s probably within a few hours of TBO, and has some numbers in the 60’s prominently marked on the cylinders.

Meet N5636A

Meet N5636A

N5636A’s avionics and instruments are as basic as it gets.  She’s got radios.  Kind of.  As to whether they’ll work on any given day… well, let’s just say that Cascade Approach has informed me a time or two that they might not be in pristine operating condition.   Three-Six-Alpha’s got a heading indicator, sometimes anyway, when the gyro isn’t stuck.   She’s got a transponder, which, again, at the prompting of local approach control, isn’t always the most accurate or most functional.

She does have a reasonably accurate magnetic compass, and a good old wind-up clock.   You heard that right.  You turn the knob to wind the clock.  Instructions (if you need them) are provided in the owner’s manual, which claims with glee “once wound, clock is accurate for up to eight days!”

***

A few days ago, I was chatting with one of my former flight instructors.  He claimed that both the written and practical test standards for private pilots were long overdue for revisions.  In his words, “no one uses pencil and paper stuff any more – let’s teach for modern aircraft, avionics, and procedures.”  I agreed.  During my training, I spent hours and hours on mock test questions which focused on penciling out wind triangles and computing magnetic headings from chart information.   I didn’t see a single question about practical uses of a modern GPS, and I began to wonder about the FAA’s emphasis areas as well.

It wasn’t just me.  I heard it from fellow students and other pilots, too.  “Why is there so much emphasis on all this old-school navigation?  This is a GPS world.”  The majority of my training took place in a Garmin 430 or Garmin 1000 equipped Cessna 172s.   Getting from wherever you were to wherever you wanted to go was ridiculously simple.  If I wanted to go to airport KXYZ, just punch the ‘Direct-to’ key, enter ‘KXYZ’, hit ‘Enter’, and off you’d go.  Follow the course line on the moving map, or set it to use the CDI, and it was nigh near impossible to get lost.  I did wonder a bit what would happen if the GPS failed; but heck, I had Garmin Pilot on my GPS-enabled smartphone, and I could always just pull that out.  In the absolute worst-case scenario, I could always resort to the NAV radios and just fly to one of those (or use them to locate my position on a paper chart).

***

So back to 5636A.   I got checked out to rent her soon after I passed my checkride.  A couple of takeoffs and landings with the FBO’s CFI, and that was that.  There was certainly some novelty in flying a vintage airplane, but my real motivation was that she was dirt cheap to rent.

My mother was the first passenger I took up in 5636A.  Mom’s a pretty brave type, so the idea of buzzing around in an antique didn’t bother her.  We took off, climbed to 4,500, and pointed the nose west towards the coast.  I’d done a bit of preflight planning and knew that it was going to be only about a 30-minute flight.  We settled in to cruise and started enjoying the views that go with a bluebird day with 40+ miles of visibility.

About halfway to the beach, she hit me with it.

“What happens if you get lost up here? I mean, yeah, we can see today, but…hmm, what if you got sick and needed to land somewhere close by?”

“Well, we have the…”

I instinctively pointed to where the GPS should’ve been, would’ve been.  Where of course, it wasn’t.

I looked for the NAV radios. I found the tuner, and then the CDI, but…it wasn’t a normal CDI like I was used to seeing.  It was some sort of electronic CDI with numbers and horizontal strength bars.  I was stumped.

I then looked to the heading indicator.  I realized it had precessed (or maybe, regressed?) about 90 degrees in the 15 minutes since I’d set it. I glanced at the compass and it confirmed that we were indeed heading west.  At least something was working right.

“Well, I know that generally we have been flying for about 15 minutes, and almost all of that on a due west heading.  So that puts us about here.”

I pointed to the chart.  I pulled out my plotter, and drew a pencil line to the nearest airport to the north.

“So, from here to this airport up here… would be a course of, um, 010, and a distance of, oh, about 15 miles.  But wait, crap.  That’s true course.  If I used that, we’d miss it by a good bit.  Shoot.  Okay, so, our magnetic variation is…”

I looked on the chart, and looked some more.  Finally I found the magenta line I was looking for.

“It’s about 16 degrees east, maybe a little more.  So that means we’d go on a 354 heading. Assuming, of course, we don’t have any wind.”

“But wasn’t it windy when we took off? Blowing pretty good, like maybe 15 miles an hour, from the west?”

Yes. Leave it to Mom to make things difficult.  I’m pretty sure she’d make a good CFI.   I rummaged around in my flight bag a bit, and found the E6B.  I drew a couple dots, spun the wheel, and finally declared “Yes, we’d need to go about 10 degrees further westerly, so about 345, and we’d be going a little slower than normal cruise. It looks like we’re doing about 95 knots over the ground now.  We’d be doing about 90 headed north, or 345, anyway, so, uh, about ten minutes more or less.”

I’d finally solved the puzzle, and we flew on.

No GPS, that’s for sure!

No GPS, that’s for sure!

In the course of training for either a sport or private pilot certificate, your instructor will ask you to plan several cross-country flights using old-school, pencil and paper navigation methods.  You will be expected to be able to calculate courses (both true and magnetic), determine leg times, and find appropriate correction angles for winds.

My training was no exception.  I’d done pretty extensive planning for the three required cross-country flights.  I had laid all my materials out on my desk, plotted, checked, and double-checked.  Usually I did the planning a day or two before, sometimes even a week, in a nice, quiet, controlled environment with no distractions and no time pressures. Easy when you’re not flying and no one’s watching.

For my checkride, the DPE had asked me to plan a cross-country flight.  I did so a few days in advance, and since I’d been tipped off, was prepared to expect a diversion somewhere after the first checkpoint.  On the flight portion exam, he asked me to divert to a nearby airport and offered me the choice to use any device in the plane.  It was easy enough to default to the ‘Direct-to’ on the Garmin 430 GPS.  I didn’t think much of it. I’d done navigation stuff plenty and was good at it.  I was sure I could do it on demand if I ever needed to.  Apparently the DPE felt that I was good enough, too, since he signed off on my certificate.

***

The rest of the flight to the coast with Mom in 5636A was otherwise uneventful.  We flew along the beach for a bit, landed, walked around the airport, then turned around and came back home. A good first flight with passengers in a new aircraft.  But I was a little shaken.  It had been far too difficult for me to complete what should’ve been a basic exercise in navigation.

I’ve since flown 5636A to many other destinations, with many other passengers.  On these flights, I’ve spent a good bit of time practicing pulling out the paper chart and plotter for diversions and lost scenarios.  It’s a great way to burn up time on a long, straight cruise leg.  When flying an aircraft without the aid of a GPS or smartphone/tablet apps, it’s also an essential safety practice to be well-versed and current in ‘old-school’ navigation. Or what if you happen to be in a GPS-equipped plane over unfamiliar terrain, and the GPS unit decides to take a vacation?

As Mom summed up succinctly,,

“Wow, that was a long time for you to figure that out. Better hope you’re a lot quicker and more accurate when you need to be.”

I couldn’t argue.  She was right.  Thanks, Mom.

Practicing old-school navigation in a Cessna 172 over the Oregon Cascades

Practicing old-school navigation in a Cessna 172 over the Oregon Cascades

1 Michael Teninty October 23, 2013 at 2:19 pm

I have never learned to use airborne GPS… I have used INS… It is just easier to use the “old school” way… The batteries never run out. One of these days I will make friends with a Garmin, but I don’t think enough can be said about having “old school” navigation skills.

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