Technique: In-flight planning

Informed on-the-go choices

December 1, 2012

Airborne changes of plans used to be leaps of faith based largely on intuition. Even if your E6B confirmed you could get to a different destination than the one you originally planned, there was no way to know just what to expect when you got there. That was true of the weather, fuel availability and prices, aircraft services, and places to stay. Flight Watch (on 122.0 MHz) and a printed AOPA Airports directory in your flight bag were the best tools available to pilots on the fly.

Today, newer cockpit tools such as satellite weather, digital AOPA Airports information (updated throughout the year), and online fuel price surveys supplement preflight planning with accurate in-flight data. On longer trips that involve multiple legs, it’s common for pilots to alter their routes and fuel stops on the fly—so much so that some of us make a habit of taking off with only a vague idea of the regions where our intermediate stops will take place.

Michael Collier, an Arizona geologist and photographer, makes detailed preflight plans for the terrain he intends to shoot from his Cessna 180 (see “Briefing: An Aerial Perspective,” page 28). But changing light and wind conditions so frequently alter those plans that he’s largely given up knowing where he will land at the end of each flight.

“It’s completely normal for me not to know where I’m going to land when I take off,” said Collier, who brings camping gear on every trip and has flown and photographed areas from northern Alaska to Central America. “That doesn’t mean neglecting preflight planning. It means planning to be flexible.”

Flexibility isn’t just limited to VFR trips, either. High-altitude winds, changing density altitudes at intermediate stops, and fuel price discounts can alter the itineraries for corporate jet pilots, many of whom have additional tools such as in-flight data and voice messaging. And during the peak pre-holiday shipping season, cargo carriers such as FedEx launch empty wide-body jets from the West Coast toward the company’s main sorting facility in Memphis, Tennessee, knowing that last-minute operational considerations are almost sure to divert them to other locations to pick up stranded packages along the way.

During a two-day, 1,600-nm trip in the AOPA 2012 Sweepstakes Tornado Husky from Bozeman, Montana, to Frederick, Maryland, AOPA colleague and CFI Alyssa Miller flew the airplane while I sized up our options from the backseat.

We’d get preflight weather and wind information, check TFRs and notams, and tentatively select a VFR destination about 350 nm away. But actual conditions so frequently changed our routes and intermediate stops that they became a running joke almost as soon as the Husky’s wheels left the ground.

Miller would take off, climb to altitude, and follow the magenta line in the direction of our ultimate destination, FDK. We’d obsessively monitor the XM Weather display on the Husky’s GPSMAP 696, note changes in our groundspeed, and scan the region ahead where we expected to be in about 3.5 hours. Once we settled on a general area, we’d set the engine power so that we’d have at least an hour of fuel remaining when we got there.

Putting the GPS cursor on that roughly 25-mile area, we’d search for airports that had avgas (ideally self-serve), maintenance (in case something broke, which it never did), and turf runways that would be easy on the Husky’s oversized Alaskan Bushwheel tundra tires. (Airport restaurants were a big plus, too, although our stops usually were so short we’d grab something out of the FBO vending machines.)

A new generation of Electronic Flight Bags (EFBs) for tablet computers provides an amazing amount of current information. It’s possible to know fuel prices, local restaurants and hotels, rental car or crew car availability, as well as the moment the sun will rise and set.

Weather forecasts also allowed for hints on the best route for the next day’s flight, but that’s not to say everything always goes perfectly, no matter how good the technology.

For example, our first full day of flying brought us to Gary, Indiana, where we stayed the night expecting bright sunshine the next morning. But a steady breeze from Lake Michigan kept the airport foggy until midday.

Once we finally got airborne, one fuel stop at Lima Allen County Airport in Ohio (on the turf Runway 14) made for a relatively short 315-nm final leg home. That last leg would have been stressful, or perhaps undoable, with the weather forecast telling of intense thunderstorms and possible lightning and hail along the route, but the XM Weather display showed storms were widely scattered and easily avoidable.

Miller said she wouldn’t have been disappointed if adverse weather required another stop or two (more Husky takeoffs and landings!) in her native West Virginia. But the trip turned out to be arrow-straight and uneventful—just as our in-flight information indicated it would be.

Email dave.hirschman@aopa.org