Weather is an especially important topic to turbine pilots because most fly true all-weather operations. Company CEOs authorize corporate airplanes because of their desire for flexible, dependable travel. Charter operators and regional and major airlines earn their money from passengers who expect arrival at their destinations on time, every time. As a result, the turbine aircraft operated by these companies are expected to fly in all but the most threatening weather. Pilots and equipment must be up to the task. This chapter covers some of the weather phenomena that you’re likely to experience in turbine pilot operations. Weather is a complex and interesting topic and one that deserves your attention in detail far beyond the scope of this book. Truly professional pilots are lifelong students of weather. Turbine pilots must be expert on both low- and high-altitude weather. Low-altitude weather, due to the approaches and departures that must be made to meet the schedule; high-altitude weather, for enroute travel at turboprop and jet altitudes. Turbine aircraft are most fuel efficient at high altitudes; the ride there is generally smoother, and they are above most of the hazardous weather typically encountered at lower altitudes. High-altitude winds can be very strong and therefore tremendously helpful or problematic, depending on conditions and direction of flight.
Low-Altitude Weather: Wind Shear and Microbursts By the time you transition to civilian turbine aircraft, you should be pretty knowledgeable about low-altitude weather and associated IFR operations. Therefore, very little of that is covered here. At the same time, you’ve probably not yet been flying in
CHAPTER 16
Weather Considerations for Turbine Pilots
some of the really heavy weather encountered in corporate and scheduled flight operations. Low-level wind shear and microbursts have been hot topics among turbine pilots in recent years. A string of major air carrier accidents has led to meteorological studies of wind shear associated with fastmoving fronts, downbursts, and microbursts. This section covers some of the characteristics and hazards of these phenomena, along with general procedures recommended by most training departments for successfully dealing with them.
Wind Shear Wind shear occurs whenever two or more adjacent masses of air are moving in different directions, resulting in a “tearing action” where they meet. Wind shear can occur in horizontal or vertical planes. Low-level wind shear refers to occurrences within 1,000 feet of the ground. Wind shear can result from any source of shifting winds or vertical air movements. As such, wind shear is often associated with passage of fast-moving weather fronts. Strong winds and uneven heating in mountainous areas are also prime culprits. In each of these cases wind shear may occur in most any type of weather conditions, including clear skies with no associated visible weather.
Microbursts Wind shear has long been associated with thunderstorms, where powerful updrafts and downdrafts exist side by side. These conditions can easily occupy areas exceeding 15 miles in diameter. Areas of extreme downdraft are sometimes called “downbursts.” Exceptionally dangerous instances of wind shear have been documented with localized downbursts of air known as microbursts (Figure 16.1). 209
