January has turned into February, which in some places is the worst part of winter. The air is cold, the ground is hovering around freezing, and precipitation this time of year often consists of ice, snow, or sleet.
Looking back to my days as a full-time general aviation pilot, the lesson that was constantly pushed on me regarding icing conditions was pretty simple: Avoid them at all costs. That usually meant not flying, which meant that a lot of winter days were spent on the ground.
The airlines operate under a different mantra: While there are some forms of weather that are unsafe, that definition is of a much smaller scope and bandwidth. If there is any way to get an airplane safely airborne, then you’re going flying. The running joke is that it doesn’t matter what’s on the radar or The Weather Channel; we’re going. There’s some truth to that.
In the Part 121 world, snowy weather is countered with deicing operations. The deicing fluids are numbered Type 1 to Type 4, with Type 4 being the strongest. The others can be a mix of fluid and water—and in some cases, you can deice with hot water—whereas Type 4 is a 100 percent mixture of stuff you do not want to drink. It’s thick, it’s sticky, and it’s expensive, so it’s only used when necessary.
Every year there are subtle changes to the various deicing protocols as new information is gleaned from research and real-world operations. From an operational point of view, two things are paramount. The first is the holdover time (HOT), which is the amount of time the crew has to get airborne after being deiced before the fluid loses its effectiveness, and the precipitation type. Mixed precip is the hardest to work with, because you need to use the most conservative HOT. For a long time, ice pellets were a challenge, and it’s only in the last few years that HOTs have been developed for pellets. At the extreme end is freezing rain. Simply put, you’re not going with freezing rain. It affects the wings, brakes, and runway surface.
If you’ve never been exposed to flying in icy weather and you’re looking to fly for an airline or a corporate flight department, take the time to do some research on deicing ops. Don’t worry about the gritty details, because every carrier’s program has individual requirements and nuances. Two carriers operating the same airplane may deice differently—for example, one will deice with the flaps up while the other will do so with the flaps down. But you should have a basic understanding of the different fluids, when they’re used, and what the limitations are. And you should take the time to fully understand your operation when you get on line.
And last, but not least, try to get trips that have you pointing the nose south after the deicing is complete.—Chip Wright