Photo: Scott Wright CCBY-SA 2.0
Winter has arrived early for some, with snow and ice abundant in northern parts of the country already! Cold-weather flying can bring smooth, calm air and great performance, but it can also bring ice and slick runways. If you’re an avid year-round flyer, then you’re probably familiar with the hazards associated with flying in the winter: cold engine starts, frost on the wings, structural icing, and slippery runways. Winter operations include preheating the aircraft, getting the frost off the wings before takeoff and avoiding icing conditions in aircraft that aren't approved for flight into known icing. There are even hazards involved with de-icing! Winter flying is enjoyable, as long as you stay ahead of these winter weather hazards:
- Cold engines
If extremely cold temperatures, it’s wise to preheat the engine before flying. Besides sluggish oil, frost can build up on spark plugs and freezing cold temperatures can also cause instruments to freeze or be sluggish – all bad news for the airplane. Engine crankcases should also be inspected during the preflight to ensure there’s no icing due to vapors condensing.
Frost and ice found on your aircraft during the preflight can be removed. Frost and ice found during takeoff, not so much. Even a tiny bit of frost on the airframe can cause a significant loss of lift and the aircraft might stall at a lower-than-usual angle of attack. Never take off with frost on the aircraft!
As winter arrives and the freezing level gets lower and lower, pilots need to be prepared for structural icing. Without a properly equipped aircraft, pilots should stay out of areas where icing is forecast or likely. But sometimes icing occurs without notice, and it can occur rapidly. To stay out of trouble, make sure you always have an escape plan if flying in the clouds in cold weather. Ice build-up on the airframe causes loss of lift, increased drag and increased weight.
If you enter icing conditions in an ill-equipped aircraft, your choices are to climb, descend or turn around. Much of the time, small aircraft will not have the performance to climb through a cloud layer, which is why it’s important to be able to gauge aircraft performance quickly if it’s reduced. It’s also very important to know where the cloud layers are. A pilot in a small airplane won’t want to try to climb if the cloud tops are at 30,000 feet. But if it’s a thin layer of clouds with, say, the base at 6,000 and the top at 7,000, you should be able to climb out of the icing conditions and get above the clouds.
In most cases, you’ll want to turn around or descend below the clouds. And don’t forget that you can enlist the help of ATC and other weather services if you need assistance getting out of icing conditions.
- Runway condition
During the winter, runways can be slick from frost or icy conditions, and they can also be wet from aircraft operating and winter vehicles removing snow. Know your aircraft’s performance and limitations with wet, snow-covered or icy runways, and make sure you give yourself plenty of extra landing space. Wet runways really do reduce landing performance.
- De-icing hazards
It should go without saying that credit cards aren’t recommended for scraping ice off airplane windshields. But every year, I hear a story about this happening. Get the ice off the recommended way: A soft brush made for aircraft can get the snow off, and de-icing fluid can melt the rest. But de-icing procedures can be hazardous if you don’t know what you’re doing!
Remember that melted ice can refreeze quickly, and you should always check flight controls and flaps, as well as hinges after de-icing, where water can drip and refreeze.
De-icing fluid should always be handled with care. A quick check of wind direction before spraying will ensure you don't get Propylene Glycol in your eyes!
Finally, make sure you’re using an appropriate chemical for your aircraft, and follow local airport procedures for de-icing areas and safety protocols.
Have your own winter flying tips to share? Let us know!