Waypoints:

A good day to fly

June 1, 2010

St. Patrick’s Day—aloft over the Appalachian Mountains. Fog spills through mountain passes like water flowing through a void in a dam, filling the valleys to near the brim, but never quite to the tops. The ridges, still bare of leaves in mid-March, arch upward toward a clear blue sky. I monitor weather reports for the valley airports as I fly along southwestward—visibilities varying from a fraction of a mile to maybe three miles; sky partially obscured. While enjoying the view from 8,000 feet, I’m also looking along the ridges for places I might land should the faithful old Continental out front decide it has had enough. There are clearings here and there that might just be survivable. Certainly one can understand why airports are always in the valleys—makes perfect sense from an engineering standpoint. Why shave off the top of a mountain when just below there is a flat plain more suitable for a mile of pavement? But the price to be paid on mornings like this is mile after mile with airports mostly out of commission as fog snakes its way through the ravines.

Ninety minutes into the flight as I near Bluefield, West Virginia, the fog thins. The chances of making it in on an instrument approach go from unlikely to probable. Meanwhile, a higher overcast layer emerges. The highly defined layer has tops right at 7,000 feet and bottoms right at 6,000 feet. It’s as if someone has placed a 1,000-foot-thick sheet of opaque Plexiglass over the region. I think about Stephen King’s recent novel, The Dome, where a community is suddenly encased in a clear and impenetrable dome. As I approach the edge of the sheet, I can see below that the fog is gone—visibilities unrestricted underneath; still clear above. Soon, though, as I fly over the sheet, the tops rise and just before I start my descent into Knoxville, Tennessee, the tops reach 8,000 feet and I enter instrument conditions for the first time that day. While it was somewhat balmy and sunny back in Maryland, here it is cool and drizzly. Pitot heat on, looking for signs of ice.

Flying a radial—really?

While the morning so far has been interesting from a meteorological perspective, it has proven challenging from a navigation standpoint. I had dropped the NavData card from my Garmin GNS 530 navigator the day before when removing it from the airplane to take it into my office for a data update. As I attempt the update, the data reader doesn’t recognize the card. After trying the update on several computers and spending time on the phone that evening with Jeppesen technical support, the belief is that the reader is defective. The old data on the card is fine, I’m told. Jeppesen agrees to send me a new reader to see if that fixes the problem.

With card and old data in hand, I head to the airport for my early morning flight to Knoxville. I slide the card into the Garmin, fire up the airplane, and begin the pretaxi check. I quickly notice the Garmin looks a little different as it comes to life and soon realize that it is not reading the NavData card. It occurs to me that I may be making this trip without the benefit of long-range navigation; flying VOR to VOR. Geez, how long has it been since I’ve done that? But wait, the faithful old Northstar M1 loran rests in the far side of the panel. I turn it on, but then remember that the FAA shut down the network of loran transmitters a month earlier. The unit struggles to find a signal and soon gives up.

I dial the Frederick VOR frequency into the Garmin to find that even without the NavData, the unit’s VHF faculties are intact. I put 112.1 MHz into both the Garmin and the number-two receiver and spin the CDIs to 270 degrees, the course to the Martinsburg VOR—first waypoint in my flight plan. How quaint, I think. Seems like 1989 all over again.

After takeoff, I track the radial to Martinsburg and reach into the storage compartment below my seat for the ace in the hole—a Honeywell AV8OR handheld GPS. Soon I have the flight plan programmed, giving me a long-range reference for the trip.

Then I look at the kneeboard printout from AOPA’s Internet Flight Planner. It has coordinates for all the waypoints along the way. Hmmm. I begin entering each of the waypoints into the GNS 530 as user-defined points. Then I use those points to build a flight plan and suddenly I’m back in business. The GPS steering function on the S-Tec autopilot even works, deriving its direction from the GNS 530. The 530 still shows satellite-delivered Nexrad images, but it doesn’t show METARs or TAFs, which are associated with airports that the navigator doesn’t know anything about without the NavData.

So while I can’t fly any RNAV approaches, I’m still good for ILS or VOR approaches—on either the Garmin or the number two Bendix/King nav/com. The handheld is providing excellent situational awareness regarding airspace and the 530 is driving the autopilot as well as ever.

So despite the convoluted means of navigating, within a few minutes after takeoff, I’m free to monitor what’s going on inside while enjoying the dynamic show outside as fog flows from one valley to the next. A good day to fly.

E-mail the author at thomas.haines@aopa.org; follow on Twitter: tomhaines29.