Winter Weather Advisory

Published Nov. 19, 2013
By Master Sgt. Julie Meintel
445th Airlift Wing

WRIGHT-PATTERSON AIR FORCE BASE, Ohio -- The phrase "winter weather advisory" can only mean one thing here in southwest Ohio. It means things are about to get ugly: snow and ice, sleet, freezing rain, and those cold temperatures.

One of the things I love about the area where I live is the change of the seasons. With each season, there are unique conditions to consider and plan for, and in the winter, snow and ice are usually a part of that process.

When summer heat fades to cooler fall temperatures, winter cold is not far off, and winter cold requires that we go about our business a little bit differently. We need to dress differently to keep warm in colder weather, and as flyers, we need to be aware of changing weather conditions. There are several well-known hazards of cold weather, but here we'll stick to the ones that affect our work as flyers: aircraft icing and exposure to cold temperatures or hypothermia. In the winter, one of our biggest concerns is aircraft icing, because this will ruin your flight, every time, if you are not paying attention.

Aircraft icing is one of those things where the requirements and definitions don't change very much. Air Force Handbook 11-203, Vol II, Weather for Aircrews, is the authoritative guide on all things weather related, and it should be your first stop when reviewing procedures as the seasons change. Chapter 11 deals exclusively with icing issues in depth. We're just painting with very broad strokes, so if you need to really review in-depth, pull out that book. Don't rely solely on your experience or memory alone.

There are two varieties of aircraft icing, structural and induction. They are what they sound like: structural icing builds up on aircraft surfaces and can add weight to the aircraft, as well as slow down moving parts. Induction icing is most common in the air induction systems, where air is taken in to the engines, but may also show up in the fuel systems. It can appear when temperatures are above freezing, so be aware that you need to watch for it.

Within structural icing, there are three sub-categories of ice: clear, rime, and mixed. Clear ice is the most dangerous of the three types; it is hard and glossy, and it is very difficult to remove with deice equipment. You will find this where you find high water content in the clouds and temperatures slightly below freezing. It sticks well to the aircraft's surfaces and can build to a dangerous level in a pretty short time. It might be smooth if it is made up only of freezing rain, but if there is snow, ice pellets, or small hail mixed in, it can be rough.

Rime ice is milky and granular in appearance, making it more brittle and easier to remove than clear ice. It is made up of small water droplets that freeze when they strike the surface of the aircraft, and a lot of air usually gets trapped in with the water, giving this ice its rough and opaque appearance. It is not as heavy as clear ice either, so its weight is not really an issue.

Mixed ice is just what it sounds like: a mix of small and large water droplets, sometimes with snow or ice particles mixed in. It builds rapidly and ice particles can become embedded in clear ice, making a rough surface.

Additionally, we have to think about frost, which is the thin layer of crystalline ice that forms on aircraft surfaces. It decreases your lift to drag ratio and obstructs your vision, although is not included in the icing categories. It can make your flight more difficult and possibly create a hazard during takeoff, so make sure it is all removed from your jet before you go.

If you are flying in this nasty weather, you might get stuck in it, too. Let's go over exposure while we're talking about cold weather, shall we? Exposure to cold air, moisture, snow and ice can really take a toll on your body, and it takes less time than you think to develop frostbite or hypothermia. As flyers, we spend a lot of our duty time exposed to the elements, especially flight engineers, scanners, loadmasters, flight nurses, and aeromedical technicians, in addition to all the ground crew that help us get off the ground. Look out for the following symptoms of frostbite and hypothermia.

Frostbite is a severe reaction to cold exposure, and it can cause permanent damage.
Some early warning signs of frostbite include:

· A loss of feeling and a white or pale, waxy appearance to the fingers, toes, nose, or earlobes
· Skin that is hard to the touch
· Redness and/or pain in the skin indicates that frostbite may be developing

Hypothermia is more serious that frostbite; it occurs when the core body temperature dips below 90 degrees F. Look for these indicators:

· Body that is cold under clothing
· Slow, shallow breathing
· Confusion, unusually aggressive, irrational, disoriented, or combative behavior
· Slurred speech
· Stumbling or unsteadiness while standing
· Unconsciousness
· Appearance of being dead

If a coworker shows any of these signs, move the victim to a warmer place, and call for immediate medical attention. Try to warm the victim gently, using body heat or warm, dry clothes and blankets. Remove any wet clothing, and heat the affected area in warm water for 15-30 minutes if possible. Do not rub any affected areas, and do not give the victim any liquids with caffeine or alcohol.

Prevention is crucial for dealing with the effects of the weather. Dress appropriately for your duties. Dress in layers of warm clothing, paying special attention to your head. The vast majority of body heat is lost from the head, so be sure to cover it with a wool hat. Mittens are better than gloves because they will keep your hands and fingers warmer but it can be tough to turn wrenches and bolts with mittens. Use your best judgment. Take breaks to go inside, warm up and dry off when you can. Check the weather reports frequently; if severe weather is called for, consider putting off outside duties until it is safer, if possible.

Be a good wingman; watch out for your people, and they will watch out for you. Keep warm!