Winter Flying
It’s that time of year again, and there’s some value in readjusting our mindset from summer to winter: cold, limited daylight, frozen ground etc. Conditions can be magical: cloudless blue skies, a low sun sparkling off the snow, smooth laminar air all contributing to having a great time, and when it all comes together there’s only one thing to do and that’s to get out there and enjoy it.
On the other hand . . .
Wind. Winter brings the top of the boundary layer much closer to the surface, and the potential for radically different airflow just above take off height is very real. Wind speed may be much higher, giving you penetration problems, and if the direction is very different the potential turbulence can leave you wishing you’d gone xmas shopping instead.
Wave. The potential for wave influence seems much greater in winter, so what feels like a gentle breeze on the ground can become a fight for survival a few hundred feet higher. Of course you can have wonderful experiences in wave, soaring smoothly ever higher, but it pays to be aware of this and have a plan for what to do if you are swept up towards controlled airspace, or the beautiful layer of smooth cloud you’ve been looking down on and filming suddenly fills all the gaps, or that laminar air you were enjoying turns into a white-knuckle ride. All these things happen – have a plan of what you will do.
Weather apps like Windy and RASP can give good, detailed forecasts of what the wind speeds and directions will be like at different heights. Don’t just look at the wind speed at the top of the boundary layer, you need to look at the Airgram diagram on Windy, or the custom sounding chart on RASP to get a fuller picture. Look for marked changes in speed and/or direction. The Met Office can supply detail on wind speeds at heights for the aviation community. If you don’t know how to use these, then spend the rainy days finding out. Remember though that these are only predictions and may not be based on the latest data. The best risk assessment is the one you continually adjust as you observe the conditions. Make sure your skill set contains all the tools you are likely to need.
Cold. Performance and decision-making deteriorate rapidly when cold, and sitting virtually motionless in a 25 mph wind makes keeping warm a major task. Usually, we moan about our hands being cold, but remember that this is a physiological response to your body core temperature dropping, and when that happens judgment and reactions may be seriously impaired. Make sure to keep your body and head warm; pay attention to keeping draughts out where layers overlap and have a completely windproof outer layer. One-piece flying suits went out of fashion some time ago, but if you still have one kicking around, they can be perfect for winter.
Ground. The ground may be frozen hard, or slippery with ice. Or it may be soft wet mud when you get to the landing area. Either can spell disaster to a cold, stiff body arriving slightly too fast.
Sun. That photogenic low sun casting such lovely long shadows? WW2 pilots had the phrase ‘beware the hun in the sun’ for good reason. Keep a good look out, as a typical winter flight involves a lot of ridge soaring with many wings at the same level, and a low sun makes them hard to spot.
Tight lines, everyone.
Brian
