Custom content for the April 1, 2011, issue of 'AOPA ePilot' newsletter

training tips

Thermals

It’s a calm, still morning with a forecast for light winds, perfect conditions for solo practice or launching on a cross-country. By mid-morning you are under way, and a scattered cloud layer has begun to develop—exactly as advertised.

Now it’s noontime, and the ride has become distinctly choppy. You, your flight gear, and the partly consumed fuel load don’t come close to maxing out your trainer’s gross weight—and the aircraft has a low wing loading—so each bump stirs up your cockpit and can cause altitude deviation of a hundred feet or more. There’s still no wind, so what’s with these bumps?

The answer is thermal currents—columns of warm air rising from uneven solar heating of the ground as the day wears on, resulting in the cloud type known as fair-weather cumulus. These clouds are signposts of a bumpy ride in the low to mid levels on a warm day. Their expected development is what produces weather forecasts calling for clear early morning skies followed by scattered to broken clouds later—and those jarring bumps.

Cruising in thermal turbulence imparts real-world experience, but there are escape strategies when you’ve had enough. One, if the clouds are not expected to develop into a ceiling, is to climb above them; their tops mark the extent of the vertical movement of air. Above, smooth flying awaits. A well-known rule of thumb lets you estimate the altitude of the cloud bases.

In coastal areas, flying a route closer to the water’s edge may offer smooth air, especially if there’s a sea breeze bringing in cool, stable air from over the water. An absence of fair-weather cumulus in that direction is the clue to look for.

If neither option is available, slow down to your trainer’s turbulence penetration speed (for your current gross weight). Giving a pilot report on your conditions is an excellent idea and will be appreciated by anyone about to set out along your route. Try to make an accurate estimate of the turbulence according to the recommended descriptive categories.

Here’s the good news about thermals: Later in the day when the sun starts down, they die out as abruptly as they sprang up, often restoring calm conditions before dusk.

training products

‘Flying the Skycatcher’ from King Schools

Is a Skycatcher in your future? If you are learning to fly a Cessna Skycatcher light sport aircraft or considering transitioning to one, King Schools has produced a training program for your Windows-compatible personal computer. Three hours of video footage includes demonstrations of all maneuvers as well as familiarity with the Garmin G300 avionics. The course sells for $149 and may be ordered online or by calling 800/854-1001.

Note: Products listed have not been evaluated by ePilot editors unless otherwise noted. AOPA assumes no responsibility for products or services listed or for claims or actions by manufacturers or vendors.

final exam

Question: What type of airspace is depicted on a VFR sectional chart by a solid black line (looks more gray to me) with altitudes for each segment surrounding a Class D airport?

Answer: The airspace is known as a terminal radar service area ( TRSA). This type of airspace, which is not controlled airspace from a regulatory standpoint, usually surrounds airports that have enough traffic to justify the presence of radar service yet don’t qualify for Class C or Class B status. Within a TRSA, ATC provides separation between participating VFR aircraft and all IFR aircraft. Note that it’s “participating” VFR aircraft, because pilot participation is recommended, but not mandatory. If you would rather not receive TRSA service, simply state “negative TRSA service” when talking with ATC. It is a good idea to participate if possible because ATC can help you approach and depart busier airports in a safe manner. For more on TRSAs and the National Airspace System, complete the Air Safety Institute’s online course, Know Before You Go: Navigating Today’s Airspace .

Got a question for our technical services staff? E-mail [email protected] or call the Pilot Information Center, 800/872-2672. Don’t forget the online archive of “Final Exam” questions and answers, searchable by keyword or topic.