Are You Ready for Winter?
By James Williams
Reprinted with permission from FAA Safety Briefing
Flying in the winter offers some unique challenges for the rotorcraft community. Temperatures drop, the days get shorter, and snow/ice/sleet become a real possibility for much of the United States. To prepare for this change in season, consider making a few changes that apply to both you and your aircraft to ensure safe winter operations.
Just as there are things you can do to get your airplane ready for the winter, there are things you can do for your helicopter. While what you might find will vary from helicopter to helicopter, there is one fact that is almost universal: It is rare for a helicopter to be equipped for flight into known icing conditions (FIKI). One of the items you might find, though, is a deflector, which keeps the intakes from being clogged with blowing snow. A simple, but sometimes overlooked item is pitot heat. Some helicopters also require the addition of a continuous ignition system.
Another concern during winter operations is rotor icing. Even though the rotor blade is moving through the air rapidly, it can still accumulate ice. As with fixed-wing aircraft, the best anti-icing strategy is to avoid potential icing when possible.
The preflight really begins before you even get to the aircraft. You can use tools like the National Weather Service’s aviation icing forecast tool to help inform your go/no-go decision (http://aviationweather.gov/adds/icing/icing_nav.php). You should also check out the experimental Health Emergency Medical Services (HEMS) tool at: http://weather.aero/tools/desktopapps/hemstool. Before you even get to the airport, though, a review of the helicopter flight manual is well warranted. Some helicopters have different limitations, especially with regard to flight in blowing snow.
Checking fuel is an even bigger concern as the temperature drops. With the addition of cold weather additives comes a new threat, known to the rotorcraft community as “apple jelly.” A gelatinous formation of water, cold weather additives, and miscellaneous components, “apple jelly” can clog fuel filters and other portions of the fuel system. The best countermeasure for avoiding this gloppy mass is to ensure that you regularly sump fuel tanks on the aircraft to keep water from getting into the fuel.
During your hands-on preflight, there are a couple of additional things to check during the winter. First is to ensure that the engine’s anti-ice system is working. This system is generally required for cold-weather operations and it is not likely to have been checked during the warmer months. Also, ensure that intake filters are clear of ice or frost. Even a thin covering could possibly choke the engine’s ability to “breathe” and produce power. Many helicopters also require preheating so components and engine oil are warm enough to work properly. Finally, there is the issue of making sure the aircraft isn’t stuck to the ground. It may sound odd to a fixed-wing pilot, but since helicopters sometimes operate from remote locations, it is possible. And, if one skid is frozen more than the other, this condition could create potential for a dynamic roll over.
For any pilot in the winter, it’s a good idea to sharpen up your night-flying skills and situational awareness. Another area to brush up on is aircraft limitations and procedures, and to take note of any updates and changes. One such change is the required use of engine anti-ice. Unlike some fixed wing aircraft, many helicopters require the use of engine anti-ice throughout the flight. It’s important to remember, though, that the engine anti-ice is an anti-ice system, not a de-ice system.
Hopefully this is a good start for your rotorcraft winter flying checklist. Let us know what other things you like to include on your personal winter checklist.
James Williams is FAA Safety Briefing’s assistant editor and photo editor. He is also a pilot and ground instructor.