Hello everyone and welcome back to my aviation blog. I hope everyone is doing well. Today I want to talk a little bit about flying in the winter. Unfortunatly it’s getting to be that time of year again. I am a summer person myself however the colder weather has it’s advantages on flying. There is a catch though, just like everything else in aviation, it’s a give and take. I want to talk to everyone about the perks and hazards of winter flying.
We will start out with the pros of winter weather flying. For starters, performance! The airplane flys exponentionally better in the winter time. That is due believe it or not to the cold air temperature. When the air is cold, the air molecules are closer together than they are when the air is hot. This makes an airfoil more efficient by essentially providing more air for the airfoil to grab at. Your wings work better and so does your propeller. The weather is generally better as well. If you live in the midwest like me, no more surprise thunderstorms that seem to just appear. No more haze either. This summer when I was surveying crops I literally watched a bunch of clouds just explode into existance. The air also gets smoother which is great for those who get motion sick. This time of year is great for me too when flying the skydivers, since the airplane engine is air cooled, overheating the engine in the climb isn’t as big of a concern.
Wintertime has it’s pros, however it does have it’s cons as well. Ice in the air and on the ground is a big problem. On the ground the problem is the same as it is for your car. You can skid off a taxiway or runway. It is even more critical in the winter that you as a pilot make sure you are watching you speed while taxiing, and not taking corners too sharply. Ice in the air however can be expenentionally more dangerous. Ice accumulation on the aircraft adds weight to the aircraft but it also changes the shape of the airfoil on the wings, which if left unchecked, can drastically reduce efficency as well as performance. Too much ice build up on the wings can even can lead to a crash. Bigger aircraft typically have systems to deal with ice like rubber boots that inflate and deflate to knock the ice off, “weeping wings” which secrete a de-icing fluid or, heated wings that use engine exhaust as the heat source, which most turbine aircraft have. For most GA pilots though we dont have any anti icing equipment except for pitot heat, so our airspeed probe doesnt ice over. So what can you do about airframe ice? For starters, when the temperature is below freezing, don’t fly into visible moisture ie: clouds. If your aircraft is left outside on the ramp, do not takeoff if there is frost or any other contamination on the aircraft either. If you do show up to the airport and your plane is covered in snow or frost, it is reccomended that the aircraft be placed in a heated hanger and left in there for two or more hours. This is to make sure that if the melting contamination drips water, all the water leaves the aircraft so it doesn’t re freeze when the aircraft is pulled out of the hanger. If ice is encountered in flight, try to descend to a lower altitude where the temperature is above freezing, if that isn’t an option then I reccomend turning around 180 degrees and getting back out of the icing. I have had to do that before and I am glad I did. I was flying a Cessna 172 at night when I flew into the clouds. The freezing level was susposed to be two or three thousand feet higher than where I was but it wasn’t. I reached up and hit the switch to turn the courtisy lights on under the wings and saw that my black tire was half white. I couldn’t climb because that wouldn’t help and ATC wouldn’t grant me permission to descend so that just left me with one option. Turn around and try the flight again some other time. For those of you out there that have de icing or anti icing systems onboard, the FAA still reccomends that you don’t sit in icing conditions for very long. The equipment is designed to get you up through or down through icing areas, not loiter around in it. De icing boots can be overwhelmed, or you can start to accumulate ice beyond the protected areas of the wing. This has caused crashes in the past. Remember when you are flying out there, ice is like thunderstorms, it’s as bad for the big airliners as it is for the small, private plane.
So to recap, winter flying comes with pros and cons. The airplane will perform better, however winter weather that causes ice can be a hazard. My rule of thumb is, if I can’t keep my truck straight on the road driving to the airport, it’s most likely not a good day to fly. Remember to fall back on your training and use your best judgement. When your flying in a general aviation airplane, a good rule of thumb is, if you absoultly have to get to where your going, it’s best to drive.
Well I hope you all enjoyed this weeks aviation blog. The link below will take you to a great pdf made by the NTSB about some crashes that were caused by icing. It also provides some great pictures showcasing the changes ice makes to the airfoil surface. If you have any comments of would like to request a topic for me to cover please feel free to drop me an email at email@example.com . Have a great week everyone and remember to keep the greasy side down.
Flight Operations Manager / Pilot
Winterset Aviation Services