A Little Snow

One inch of dry, powdery snow on clean pavement is navigable for most airplanes fitted with standard six-inch tires. That same inch composed of wet, slushy snow is much more difficult to handle. That is, it’ll take more power to push through it and it’s more likely to accumulate on brakes, wheels and landing gear fairings and wheel wells. So, be prepared to learn just show much of what kinds of snow your particular airplane can negotiate safely.

Where will frozen white stuff present the greatest problem? Most new-to-winter pilots are concerned about trying to stop after landing, but over the years I’ve seen more challenges during takeoff than in the landing roll-out. Brake-dependent high performance aircraft obviously need dry runway to meet their normal landing distance numbers, while light airplanes slow down reasonably well with the added drag of snow accumulation. On the other hand, taking off from a snow-covered runway, particularly with low-horsepower planes, may find you plowing along at terminal velocity well short of unstick speed.

Packed snow and ice, often the result of attempted snow removal, provides much less braking traction than loose snow. One should double the usual dry-surface stopping distance, just for starters, and be aware of a significant crosswind component’s effect on your ability to hold the airplane straight. A wet, melting snow/ice surface presents a “nil” braking action. Snow can also lead to “reverted rubber hydroplaning” when locked-up tires generate heat from sliding, creating steam under the immobile tire that melts away the tread while providing no braking.

Assessing the suitability of a landing surface from above, with no input from observers on the ground, is difficult when all you can see is unbroken white. Be not the first to try a landing; look for tracks left by previous users, and note the difference between tricycle landing gear and four-wheel-drive vehicles. Snow depth is tricky to ascertain, even from a low pass; if you can’t tell for sure, don’t try to land. I have made experimental touch-and-goes on an unbroken runway, but that technique carries some risk.

It’s far better to be on the ground, where you can check for snow depth and hidden drift fingers emanating from “push piles” along the runway sides. Taxi carefully, pretending you have no brakes, and be ready to advance power if you feel the aircraft bogging down in the snow; keep it moving, because if you let it stop you can not be able to start again. Try not to let one main wheel run through a patch of deeper snow, which can slew you off track before you can correct.

Be particularly aware of the danger posed by flat lighting on snow-covered landscapes. With a fresh snowfall on top of piles of “used” snow and old drifts, paired with a lack of shadows on an overcast day, you will not see a snow berm or other obstruction until you run into it.

Operating in a little snow merely adds to the sense of accomplishment during winter flying. Just make sure that it’s only a “little”, and that your developing experience leads you to an understanding of your aircraft’s snow limitations.