by Jeb Burnside
Each flight begins with some sort of plan. For many flights, especially those in the vicinity of an airport or over a known route, little or no planning can be necessary or appropriate. But for longer flights, perhaps long enough to raise questions about your fuel supply, over unfamiliar territory and/or in weather, putting together a detailed plan is definitely the way to go.
Any pilot shop or catalog house has a myriad of tools and gadgets supposedly designed and marketed to make some aspect or another of our flying easier, more efficient or safer. But the real measure of any aviation tool or gadget is the extent to which, if any, it enhances safety. With that question in mind, we looked at several different flight-planning applications to get an idea of whether they helped or hindered safety. We looked at stand-alone, PC-based applications, Web-based services and at the free services like Duat.We werent interested in things like value, ease of installation, technical support or how much disk space they occupied. Instead, we wanted to assess whether they enhanced safety and how best to use them once airborne
There is no single accident-cause category for mishaps involving poor flight planning or blind adherence to a plan that just wont work. Still, we can look at the categories that do exist for some ideas on how properly using flight-planning tools can minimize accidents and enhance safety.
One good example is fuel exhaustion-plain, simple running out of gas.Another is weather, either the classic VFR-into-IMC accident or simply an Instrument-rated pilot and capable aircraft getting into something they cant handle. According to the 2003 AOPA Air Safety Foundation Nall Report, these kinds of accidents were responsible for 11.2 and 13.6 percent, respectively, of all pilot-related GA accidents during that year. In other words, about 25 percent of all accidents attributed to pilot error instead of another problem like engine failure can be traced to failure to plan a flight or to monitor the plans progress once airborne. Unfortunately, theres no data available on what kind of flight planning these pilots conducted before takeoff, or even if there was a plan.
The first thing we noticed is that many of these applications are very sophisticated. At the high end, they want to do everything for you, from weight and balance to fuel consumption and creating and filing a flight plan.Only the user can decide if he or she wants or needs that much help.
But, like any automation-a computerized speadsheet or an autopilot coupled to a GPS navigator-if the user doesnt plug in the correct data, the results will be less than satisfactory. Make an error entering basic data like an hourly fuel burn or your airplanes CG range and the results will be off, sometimes significantly. Garbage in, garbage out.
Especially when starting to use a specific flight-planning package, learning its quirks and how it handles various aspects of automating the process can be critical. Another example is when the application uses winds aloft data to compute fuel consumption down to the last gallon-how valid are those wind forecasts? How accurate is your estimate of the fuel needed to reach your cruising altitude? Did you include the extra 15 minutes waiting for a clearance, or the off-course vectoring ATC always seems to throw at you when youre launching on a max-range trip? With some airplanes, we might only be talking about a couple of gallons. But, it adds up. Of course, your tanks were completely filled at engine start, werent they?
While the automated flight plan may demonstrate you can make that max-range flight without a problem, thats only true if the winds blow as some weather-guesser forecast they would. Youll still have to monitor your fuel burn and do the in-cockpit math to decide if you have enough gas to get where youre going.
Depending on your typical flight operations, these may not be concerns.But, if youre flying a new-to-you airplane, if you rent and never fly the same airplane enough to know all of its quirks, or if youre relatively inexperienced at cross-country flight planning, putting all your faith in one of these applications may not be the best idea.
Keeping a running tally on your fuel consumption is something these applications make relatively easy. You can usually make them spit out a detailed, leg-by-leg fuel burn estimate. But how do you know if consumption is keeping up with the estimate?
If you dont have a hyper-accurate fuel totalizer, the best way is the same way Lindbergh did it all the way to Paris: Set power by the book, know your consumption rate and use a watch.
Flying The Weather Plan
Retrieving and displaying weather data is one thing at which current flight-planning applications excel. But, having all the necessary weather information and forecasts at your fingertips doesnt mean a thing if the situation changes.
Fronts can change their rate of advance, thunderstorms pop up where you dont want them and icing can appear where no one thought it would. In fact, the only times Ive ever picked up airframe ice are the times when it wasnt in the pre-departure forecast.
These days, seemingly all flight-planning applications are capable of accessing a Duat vendor or Trade-A-Planes WeatherTAP service to download textual weather information and graphics. In fact, our brief, informal survey of the market did not uncover an application that couldnt do this.
But plugging current weather data into your flight plan and realizing when the forecast has gone bust are two different things. Even the highest-end flight-planning packages cant part the low fog that forms at your destination after takeoff. Keeping tabs on weather developments while airborne is the only way to keep your plan intact.
Nowadays, there are a lot of tools available for that task, too: In-cockpit weather is becoming more ubiquitous on every flight. At the end of the day, however, you still need to listen to the Hiwas broadcasts or give Flight Watch a call every now and then. When the weather goes down the tubes, the best tools are information and fuel. Use the former to make an early divert decision and the latter to get there.
The Bottom Line
And thats the bottom line for us when it comes to using anything among the wide range of flight-planning tools presently available, whether theyre dedicated software packages, by-subscription Web sites with all the bells and whistles, a Duat front-end or a cellphone and the back of an envelope. All the flight logs, weight and balance data and computer-generated charts you can stuff into your cabin wont matter much if you dont monitor things while en route and regularly ask the howgozit? question.
The information available and the ways in which its presented vary from application to application, but its all there. It remains for the pilot to make intelligent decisions on how or whether to make the flight. And thats always the way its been.