Plane & Pilot
Tuesday, October 5, 2010

Managing Risk: VFR Versus VMC

Are you prepared for when the weather deteriorates?

Next, determine whether those conditions are adequate to safely transit the proposed route of flight. Basic VFR conditions in the prairie states may result in IMC in mountains. When the flight takes us over water or trackless terrain, even five miles’ visibility may not be adequate for safe operation. What are the alternates and the options if the weather deteriorates while you’re en route?

To develop your weather-evaluating skills, check weather forecasts for your local area even on days when you don’t intend to fly. Then watch the weather as the day progresses. Was the forecast accurate? If not, how was it inaccurate: in what the weather did, or in when it changed? When you’re driving or looking out the window, imagine what that view would be like in an aircraft operating under VFR. The idea is to learn to picture what forecasted weather actually looks like.

On days when you opt not to fly because of forecast inclement weather, pay attention to the actual weather conditions as the day progresses. Again, rate the forecast accuracy and your decision making. This’ll not only help you to visualize weather conditions based on a forecast, but also help you to improve your own forecast-evaluation skills.

Find a competent instrument instructor who’s willing to do some VFR flying on a marginal day. Use good judgment in your choice of places to fly and the weather in which you fly. Study the country on a clear day in advance, so that you have a good hazard map of obstacles and their heights prior to flying on a poor-weather day. Above all, be sure that you have the option of safely transitioning to IFR or landing if need be. This experiment will further assist you in visualizing weather from the cockpit. The idea of this exercise isn’t to train you to fly in marginal conditions, but rather to show you just how ugly marginal VFR conditions can be, and how disorienting and dangerous those conditions can be. The idea is to encourage you to avoid those conditions.

Having and maintaining options is essential when operating in lowering weather conditions. Knowing where that nearest airport is, what the heading back to better weather is and what the terrain is like around you is essential situational awareness. Don’t allow yourself to get into lowering conditions without good situational awareness, and lots of options.

Finally, it’s advisable to get an instrument rating and stay as current on instruments as your budget will permit. An instrument rating is no guarantee of immunity, however—every year, a few instrument-rated pilots succumb to what the NTSB refers to as “continued VFR flight into IMC” and fly their aircraft into a mountain or other object, albeit right side up.

If you find yourself entering marginal VFR, perform a strategic retreat, and the earlier, the better. The transition to marginal conditions often comes close to the destination, when the pilot is reluctant to give up. This is precisely when never allowing yourself to fly into conditions without a “plan B” and being willing to exercise it pays off.

Good weather-evaluation skills should help avoid marginal conditions; and good training, some structured exposure to marginal weather conditions and a good set of alternates can save the day if you do get into lowering conditions.

Mike Vivion served as a wildlife biologist/pilot in Alaska for nearly 30 years. He now coordinates the aviation program and flight-instructs at the University of Minnesota in Crookston. He’s a caretaker of a modified 1952 Cessna 170.


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