Weather

Weather is a top concern that affects the logistics of whether we'll be able to fly. Pilots are trained to understand weather theory, interpret data, and make effective decisions that prioritize safety above all else. This page is for people who want to understand in a bit more detail what things I am considering.

Clouds and visibility

As a non-instrument rated pilot, I can only fly where I can see out the window. See my personal weather minimums for specific limitations.

In addition to clouds, fog, haze, smoke, or other obstructions might limit visibility. Visibility is measured in miles (how far can you see?), and I only fly when visibility is above 5 miles. Visibility is of particular importance if we are flying near mountainous terrain, like in the White Mountains of New Hampshire.

Temperature

East Coast Aero Club's winter operations require the air temperature (actual and forecasted) to be above 10 ºF (-12 ºC). Lower temperatures are actually better for flight performance, as long as we don't build up ice. If the temperature is below 40 ºF (4.4 ºC), we need to call in advance for an engine pre-heat.

Ice

I will obtain an official weather briefing within 6 hours of any flight we take, and if there is any forecast or reports of ice in the vicinity of our flight path (both departing and returning legs), I will cancel.

Wind

There are three kinds of dangerous wind forecasts: high speed, gusts, and wind shear.

High speed winds, generally above 25 knots, are not dangerous on their own. When straight down the runway, they can actually help a plane land more safely by decreasing the effective ground speed as the wheels touch the ground. Wind is rarely perfectly aligned with a runway, and high speed winds have a tendency to come with strong crosswinds, which can add risk to a landing due to the uneven forces on the wheels.

The gust factor of wind refers to the fluctuation. Gusty wind can be unsafe because the sudden change in wind can destabilize an approach. To be safe, I only fly in gust factors of 10 knots or less.

Finally, wind shear is gradient of difference in speed or direction over a short distance. There are many kinds of windspeed, but the most dangerous ones reduce airspeed on approach. This can result in an aerodynamic stall, which is very difficult to recover at low altitudes. If there's any forecast or reports of wind shear at any potential landing location, we will not fly.

Other factors

Weather is an incredibly complex topic, and there is a lot more to consider than just the above. My commitment to you is that our flight will be safe, and I will never put us in a dangerous situation.