Waypoints

Volumes have been written about moving up to higher-performance aircraft. Writers extol the virtues of folding gear, constant-speed propellers, and the allure of burning jet fuel — oh, the roar of thrust reversers reverberating across a quiet ramp; the jet pilot who walks on red carpet, garners "free" ice, and overpays for catering.

The first time I flew a Learjet, it was all I could do to keep from busting the 200-knot rule in Class C airspace. Despite several hours in the simulator ahead of time, I found myself playing catch-up in the cockpit as the airplane rocketed upward, still accelerating with the VSI pegged. That is not the time to be gentle on the thrust levers. But after a few minutes, my mind went into fast forward and I could begin to anticipate the necessary control inputs and power changes to make the airplane do what I wanted, thanks mostly to the prep time in the sim.

But what about going the other way — for example, moving down the scale from a high-performance airplane to a simple single? There's a lot to consider in that scenario, too, as I recently discovered.

Over the past few years, most of my cross-country flying has been in a Beech A36 Bonanza. It's a very capable airplane, cruising at 170 knots true airspeed and equipped with weather radar, Stormscope, three-axis autopilot, and IFR GPS. I'd give up a few knots occasionally for another hour of fuel or enough payload to carry four people in the six-seat cabin. In the winter, when there are more icing sigmets flying than airplanes, I'd give up a lot more than that for an ice protection system that didn't weigh 100 pounds and cost as much as a nice Piper Cub.

Lately, though, I've made several cross-countries in the Cessna 172 that I purchased earlier this year. Arrive in a Skyhawk and you don't get the red-carpet treatment and the ice isn't free — or even offered.

It's a solid little airplane that, like the battery-powered bunny, keeps going, even though the engine is now beyond the recommended overhaul time and the airframe has soldiered through 20 frigid winters and scalding summers. It's no wonder the windows are crazed and the interior plastic has more fractures than an orthopedic ward. A pair of flip-flop slide-in replacement radios occupy the space once devoted to the Cessna nav/coms. An old loran provides point-to-point navigation, unless the point you want isn't in its wildly out-of-date database.

Everything works, though, and the engine seems to be doing fine. Still, I couldn't resist the urge to know what was happening inside the powerplant, so I installed a JP Instruments EDM-700 engine analyzer. I'm still learning what it's telling me, but I like the comfort of rolling down the runway during takeoff and seeing all the bars jump to attention, letting me know that combustion is occurring in all four cylinders.

The only other addition since the airplane purchase is a pair of sun visors from Rosen Product Development. The original visors were woefully inadequate; as near as I can tell their only purpose was to collect dust and to droop down at the most inopportune time. The new see-through Rosens cut the glare and still allow you to see oncoming traffic.

Confident in the airplane with its new gear, I launched for Sun 'n Fun in Lakeland, Florida, last April in the wake of an early spring cold front. Predictably, the front left behind strong winds and scattered to broken clouds over the Mid-Atlantic region. Further south, the clouds lifted and eventually dissipated altogether, but the wind and turbulence hung in there all day.

The 730-nautical-mile trip would have been an easy excursion in the Bonanza — 5 hours' flight time and one stop. Get a weather briefing and go.

The Skyhawk's slower speed, though, demanded more planning, including a more thorough weather briefing. Thunderstorms were forecast to crop up in the Lakeland area by late afternoon. A reasonably early departure time in the Bonanza would mean an arrival well ahead of the storms and before 1 p.m., when the airport closed for the afternoon airshow. Short of leaving well before sunrise, there was no way to do it in the Skyhawk and beat the storms and the airshow. Leaving later in the day, however, meant even more turbulence.

I decided to leave mid-morning, allowing lots of time for weather diversions. If I arrived in the Lakeland area before the airport reopened at 6 p.m., I'd just land somewhere and wait it out.

As it turned out, the airshow and thunderstorms were no factor. Twenty- to 25-knot headwinds slowed my groundspeed to highway speeds. With a couple of stops, the journey took 10.5 hours, 7.9 flight hours. I arrived at Lakeland at 8:35 p.m., which, it turns out, was just as well, because by then the traffic had calmed down and I was able to easily swoop onto the active "runway" at LAL — it's actually a taxiway during the 51 weeks of the year when Sun 'n Fun is not in session.

While I was watching the trucks cruise down Interstate 95 at speeds only a little slower than mine, several observations came to mind. The limits of an airplane are measured in time, not distance. The Skyhawk is a terrific personal airplane and an excellent means of transportation — even with a strong headwind — for distances of up to 600 nautical miles in any one day. You can do more, and I have lots of times, but any longer than that and the turbulence and hand flying get to be a lot of work, particularly if there is no other pilot on board. A better measure, though, is time. Two 3-hour legs make for a pleasurable day of Skyhawk flying. If the destination is farther, make it a 2-day vacation.

The Bonanza, with its autopilot, all-weather gear, and greater speed, is good for about 1,000 nm a day — again, two 3-hour legs.

Flying slower makes flight planning more difficult. The weather is more likely to change over the greater time period, so it's imperative to update the current conditions regularly, using flight watch and flight service. Sometimes slow can be good. A big boomer moved through Lakeland in the late afternoon — about the time I would have been arriving, had it not been for the unmerciful headwinds.

Accurate winds-aloft forecasts become more important the closer you get to highway speeds. A 20-knot headwind instead of a planned 10-knot headwind will add only 21 minutes to your Bonanza flight on a 730-nm trip. The same increase in headwind component will add 54 minutes to a Skyhawk excursion — your ride waiting at the destination either will think that you entered the Bermuda Triangle or will start calling out the Civil Air Patrol.

The slower you go, the longer you are exposed to the headwinds and the greater the effect on flight time. For example, a 10-knot headwind represents about 10 percent of a 172's cruise speed; on a 6.5-hour trip, that will add 9 percent to your flight time. The same wind represents only 6 percent of the Bonanza's cruise speed, and it will add only 7 percent to the trip time. The effect of winds makes fuel planning even more critical in slower airplanes. And light airplanes are less likely to have snazzy fuel computers to help with that task.

A longer trip makes the speedier airplane more efficient, even considering the greater fuel burn. The 172 burned 133.5 gallons on the round trip, which took 15 flight hours. With almost twice the horsepower and hourly fuel burn, the Bonanza would have used about 150 gallons during its 10 flight hours. At $2.25 a gallon, that's only $37 more in fuel, for a savings of 5 flight hours. Of course, there's a lot more to operating costs than fuel.

If I had been renting the Skyhawk for $70 an hour wet, the bill would come to about $1,050. An A36 Bonanza is likely to rent for about $150 an hour, or $1,500 for this trip. Is the $450 cost savings with the 172 worth 5 hours of extra time? If you make less than $90 an hour, maybe so.

On the other hand, if time and dollars are your only measure of general aviation flying, you picked the wrong recreation and means of transportation. GA can be an efficient way to get around the country, but its real utility can be realized only when you recognize it as a terrific means of recreation that happens to allow you to get from one place to another a lot faster than your boat.