Plane & Pilot
Tuesday, October 5, 2010

Managing Risk: VFR Versus VMC

Are you prepared for when the weather deteriorates?

It has been a long day on a long cross-country flight. The weather forecasts have not been very accurate—you’re reminded of a quote from an anonymous wag: "Weather forecasts are horoscopes with numbers." Low ceilings and fog delayed your departure, and now you’ll be pushing sunset to reach your destination. Nevertheless, the weather has remained basic VFR, although lowering ceilings have forced you to fly at a lower altitude than you flight-planned. As the flight progressed, you’ve gotten more comfortable with this low altitude.

As you approach the last ridgeline nearing your destination, the visibility starts to diminish in mist. You notice tendrils of fog forming ahead and below you. Forty minutes ago, the METAR at your destination indicated basic VFR conditions. Barely. You recall that the temperature and dew-point spread at that time was one degree. You’re 15 miles from your destination as the sun approaches the horizon. The better visibility the METAR reported must be just around this next ridge. But as you clear the ridge a few miles from your destination, you find yourself suddenly in instrument meteorological conditions at low level, in terrain. Historically, that has been a recipe for disaster. The pilot described in this vignette had no intention of flying into poor weather, but weather flying can be one of the most challenging aspects of VFR flight.

Improving Training
A significant part of pilot training involves interpretation of weather data and weather-related decision making. General aviation accidents involving poor pilot weather decision-making account for about four percent of the total accidents each year, but as reported by the AOPA Air Safety Foundation, they represent 14% of the fatal mishaps. Unfortunately, basic flight training doesn’t always provide the pilot all the tools needed to operate safely in VFR weather.

I’ve lost track of the number of pilots with whom I’ve discussed marginal weather flying during flight reviews who firmly asserted that they’ll never fly in marginal weather. While this may represent their best intentions, sometimes events overcome us, and it’s important to be prepared.

There are a couple of areas where I think we could do better in both initial and recurrent pilot training. Pilots need to develop a better understanding of weather terminology as well as weather theory. Too many instructors simply teach the material that’s tested on the FAA Knowledge Test.


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