Tuesday, March 11, 2014
The Season Of Turbulence
The summer heat is around the corner, and so is the cobblestone sky
First things first, though not necessarily in that order. By far the easiest of these is to confine your flying to the times when turbulence is minimal, especially the early morning, before the sun's heat has had a chance to warm the air, and late afternoon/early evening when the temperature drops and the ground begins to cool.
If I need to cover long distances in the heat of summer, I make it a point to plan my departure as near sunrise as possible. When the weather is good and I don't need to file IFR, I'll often schedule takeoff for an hour before sunrise. Since I live on the bottom-left corner of America (you certainly can't get more bottom left than in California), most of my trips are north or eastbound.
Flying outbound, I'm obviously at a disadvantage because of time changes working against me, but if I depart at stupid-dark-thirty, 6:30 a.m. or earlier, I can usually get in the first four-hour leg before noon, then decide how much farther I wish to go in the heat of the day.
A second method of flying smooth(er) is to fly higher than you normally might. In summer, I'll nearly always choose 9,500 feet, 11,500 across the Southwest, eastbound, and that often allows me to top the chop. If the turbulence follows me higher, I'll unpack the oxygen masks and climb on up to 13,500 or more. Merely cruising high won't always work in the pit of summer, however. You can top all the bumps some of the time and some of the bumps all the time, but you'll never top all the bumps all the time, unless you're flying a U2.
If you wind up flying later than you hoped, more the rule than the exception, you can sometimes turn convective activity into a partial ally rather than a dreaded enemy. Sailplane pilots are taught to look for rising air, and some will deliberately fly beneath the largest cumulus clouds they can find.
Almost by definition, air must be rising to form a cloud. Similarly, there's probably little rising air in those often inviting blue holes between clouds. Without an engine out front to provide motive force, glider pilots are always in search of altitude, and they'll try to hopscotch from one cloud to another, sometimes even diving through the clear areas between clouds, to minimize altitude loss.
If there are no clouds in sight, you can usually recognize the top of the chop by the ceiling of the haze layer. The air above the haze should be smooth. Unfortunately, the summer haze layer these days sometimes rises well above the service ceiling of many general aviation airplanes.
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