Tuesday, March 12, 2013
Weather Avoidance Techniques
Staying Out of Trouble When it isn’t CAVU
The most fundamental tool is available to all pilots: It's the Mark I Eyeball. Most of us have two, and if you're flying with a copilot or passengers, you may have spares available. It's easy to use and has just one significant limitation: You have to look outside the airplane. Stay out of the clouds, and you're almost guaranteed to avoid the worst effects of weather. This is a useful technique not only for visual flight rules (VFR) pilots, but also for instrument flight rules (IFR)—operating on top or between the layers, where you can see, is an ideal way to avoid nasty surprises.
Another tool is available to any pilot with a working radio: Flight Watch, which you can reach on VHF frequency 122.0 (when calling, give the nearest VOR: "Flight watch, N12345, Fortuna"). This will connect you with a flight service specialist who has access to current weather, including radar imagery.
Tell the specialist where you are ("12 miles east of Fortuna on the 260 radial, 6,000 feet") and where you're going, and you'll get current conditions, Airmen's Metereological Information (AIRMETs) and Significant Metereological Information (SIGMETS) and an outlook for your destination. On cross-country flights, I generally try to contact Flight Watch at least once on each leg—hourly on long legs. More than once, I've been alerted to problems in time to take action before a situation became serious.
For IFR pilots, an additional (and very important) tool is whatever ATC facility you're in contact with—center, approach, departure or a local tower. Most ATC facilities have radar with some weather capabilities. They're also in contact with other airplanes, which may be flying ahead of you on the same route.
If it's getting rough, precipitation is increasing and you're starting to wonder if continuing on your current route is really such a good idea, ask ATC if anyone's ahead of you—and how it's working for them—or what the weather looks like up ahead on the radar. If an airliner ahead is reporting a rough ride, or the last couple of airplanes missed the approach, or a suspected thunderstorm cell is moving across your route, it would be nice to know ahead of time!
Beyond the Mark I Eyeball and helpful folks on the radio, a number of devices are available that give the pilot a picture of the weather. Of these, the most common (and least expensive) is data link weather, provided either by satellite or a ground-based system, such as the FAA's Flight Information Service (FIS), a component of Automatic Dependent Surveillance (ADS/B).
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