Preflight

Two things to avoid

To date I've had just one up-close-and-personal encounter with each, and that's been enough to cement those phenomena in my mind as situations to avoid in flight. As a student pilot, you'll avoid both if you abide by the regulations and the limitations imposed by your flight instructor -- but after you earn your certificate, you alone are responsible for your decisions. Both encounters were early in my aviation experience, and I was with another, much more experienced pilot who taught me a lot about aeronautical decision making.

We encountered the thunderstorm more than a decade ago over Cuba, flying back to Key West, Florida, from the Cayman Islands in a Cessna 182. Back then no current weather radar imagery was available in the Cayman Islands meteorology office. Our weather briefing consisted of a faxed radar summary chart that was several hours old and the admonition, "The weather is the weather, mon; she will be no problem." Weather reports weren't available from Cuba, but we were leaving early in the day to avoid convective thunderstorms that we knew were likely to develop later.

The airplane had a Stormscope, which shows where lightning is occurring, and we were deviating to avoid an approaching area of lightning activity when -- wham! We were enveloped. Thunder rumbled over the roar of the engine (this was before noise-canceling headsets, too). But what I remember most is the beating of the rain against the Cessna's windshield -- it was almost deafening. The rain was falling so hard that I expected it to flood the aircraft's induction system and drown the engine. Although it felt like we were in that storm forever, we exited the worst of it in two or three minutes, and in 10 minutes we were in clear air. I've successfully avoided a recurrence.

My icing encounter came in the same airplane -- but it wasn't during the frigid winter months, when one tends to think of airframe icing. Instead, it occurred during July, when we had climbed above 12,500 feet in an unsuccessful attempt to stay above clouds over Lake Michigan. Cloud tops can be particularly conducive to icing when the temperature's at or below freezing, and that's where we were. The intensity of icing, like turbulence, is in the eye of the beholder. Since then I've learned that what seemed to be a moderate accretion was only light icing -- nevertheless, we quickly negotiated a descent to warmer temperatures. (The airplane was close to its service ceiling and climbing would not have been practical, even though we had supplemental oxygen aboard.)

Since then I've probably altered more flights because of the icing risk than thunderstorms, but that's largely because of where I fly in the northern Mid-Atlantic region. During the winter here, an instrument rating is often more of a conversation piece than a practical tool -- at least for those of us who fly piston-powered, single-engine airplanes, very few of which are equipped with ice protection equipment.

NASA aircraft icing experts (see "Surviving an Inadvertent Icing Encounter," p. 28) note that icing protection isn't always an "out" -- instead, it should be thought of as something to buy the pilot additional time to exit icing conditions. Bill Rieke and Kurt Blankenship, NASA researchers whom Leslie Sabbagh interviewed for the article, also appear in Icing for General Aviation Pilots, an excellent 55-minute DVD produced by NASA's Glenn Research Center in conjunction with the AOPA Air Safety Foundation (ASF) and the FAA. I learned a lot by watching it, and you will, too.

Where should you look for airframe ice? It accretes first on aircraft components with a small radius or thin leading edge, so look at the outside air temperature probe or, if you fly a high-wing Cessna, the wing struts. The horizontal stabilizer usually has a sharper leading edge than the wings and collects ice more efficiently; if you can see ice on the wings then you should assume there's already ice on the tail. NASA's research has increased the available knowledge about icing and tailplane stalls, which can result from ice accumulation on the horizontal stabilizer or stabilator.

Icing for General Aviation Pilots is packaged with two other programs, Tailplane Icing and Icing for Regional and Corporate Pilots, and it is available from Sporty's Pilot Shop for $10. ASF also has two informative

Safety Advisor publications -- Aircraft Icing and Aircraft Deicing and Anti-icing Equipment -- that you can download and read anytime (use the convenient links). Should you ever find yourself inadvertently in icing conditions, the knowledge offered by these resources will be invaluable.