No one enjoys turbulent flights. Keep things steady with these avoidance tips.
For 2016, the FAA reported that the number of injuries due to turbulence more than doubled the previous year’s count. Certainly, some turbulence will either be unavoidable or undetectable, but improved knowledge of both indicative weather patterns and predictive methods can help avoid as many injuries and disturbances as 2016 saw.
The most obvious originator for turbulence is a thunderstorm, and while all pilots should know how to avoid them, oftentimes unnecessary turbulence encounters occur as a direct result of that avoidance. One way in which that occurs is by a pilot trying to avoid a forming thunderstorm by skirting over the top of it--a dangerous and ill-advised prospect. A turbulence “bubble” tends to rise above forming storms, often stretching thousands of feet over. Rarely should overflight be your escape route; it’s nearly always best to choose a different route.
Speaking of severe weather, recall that cold fronts bring all sorts of trouble with them as they push their way into warm air. Aside from clouds, storms, and squall lines, such fronts often bring heavy frontal turbulence along their edges. In general, you should avoid flying directly into a fast-moving cold front for all these reasons. Attempt to plan flights prior to or after known cold fronts pass, recognizing that this isn’t always a workable solution. Warm fronts also bring potential for turbulence, though to a much lesser extent than cold.
Mountain wave turbulence can often be invisible, though standing lenticular clouds over mountains may herald its presence. The most favorable conditions for mountain waves are:
- Wind at 25 kts or more
- Wind blowing perpendicular to the top of a mountain range
- Wind increasing speed with height
- Stable atmosphere
These conditions are prime for pockets of air to rise over the top of the mountain, drop to their original altitude, and then bounce along after that coming off the side of the mountain. Use extreme caution along the leeward edges of mountains as wave turbulence can be some of the most intense you’ll experience.
If you’re flying high already, clear air turbulence becomes significantly more likely once you hit the jet stream, especially with winds above 110 kts. Strong wind shear as winds rapidly shift away from the jet core will create the often-undetectable CAT. Modern weather and turbulence reporting equipment has come a long way in helping pilots avoid CAT--your best bet is to pay attention to forecasting, plan accordingly, and, if necessary, be willing to adjust the plan.
On warm days, consider flight above the clouds to avoid thermal, or convective turbulence, which occurs due to uneven heating of the earth’s surface. Cumuliform clouds may point to thermal turbulence, or you may simply experience a “dry thermal.” Such turbulence is especially pronounced as you approach the landing area and can lead to over or undershooting the runway. Make use of PIREPs to plan your approach accordingly...and don’t forget to report that turbulence yourself, in every case.
Related CTS Training: