AOPA Online Members Only -- AOPA ePilot Custom Content -- Vol. 7, Issue 33

The following stories from the August 19, 2005, edition of AOPA ePilot were provided to AOPA members who expressed an interest in the particular subject areas. Any AOPA member can receive information tailored to their areas of interest by updating their preferences online.

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My ePilot - Piston Single-Engine Interest
SAFELY OVERCOME A VACUUM FAILURE IN YOUR AIRCRAFT
Many pilots don't anticipate having a vacuum system failure in flight, but it happens more often than you may think, as Alton K. Marsh points out in " Vacuum system failure: Say goodbye to your flight instruments," in the June 1999 AOPA Flight Training. Marsh explains the importance of cross-checking the instruments and practicing partial-panel flying. He also recommends installing a backup system in your aircraft. "It's possible to have backup systems even in the single-engine piston world," he writes. More information about dealing with vacuum system failures is available in Scenario 4 of " Say Intentions," one of the numerous free online courses available in the AOPA Online Safety Center.

My ePilot - Piston Multiengine Interest
ESTABLISH WHO'S PIC
Regardless of your rating or the aircraft you are flying, make sure you establish who will be pilot in command. James Keldsen, a commercially certificated pilot working on his multiengine instructor rating, and his flight instructor learned that lesson the hard way. In the December 2003 "Never Again Online" article " Pilot in command," Keldsen shares how the failure to establish who was PIC contributed to an accident in a Piper Apache that destroyed both propellers and engines and collapsed the nose gear. "On our flights, with two experienced pilots in the airplane, we never fully decided who was pilot in command," he explains. "We should have agreed on who would control what during every part of the flight."

My ePilot - Turboprop Interest
TURBOPROP LINEUP: WHAT'S OUT THERE
Today's turboprop market is certainly spooling up. To give you an idea of what's out there, Thomas A. Horne compiled a roundup in " Turbine Pilot: The Power of One" in the April 2005 AOPA Pilot. Read about the Cessna 208 Caravan, EADS Socata TBM 700C2, Pilatus PC-12, New Piper PA-46-500T Meridian, and more. Each entry includes a brief review of the aircraft along with price, performance characteristics, and a link to the manufacturer's Web site.

My ePilot - Student Interest, Training Tips
DYNAMIC HYDROPLANING
Maintaining your aircraft tires at the correct pressure for performance and safety was the message of the August 12, 2005, "Training Tips." One risk amplified by soft tires, but always present when landing on a wet runway, is a phenomenon called "dynamic hydroplaning." This occurs, says Chapter 9 of the Pilot's Handbook of Aeronautical Knowledge, when the tires "ride on a thin sheet of water rather than on the runway's surface. Because hydroplaning wheels are not touching the runway, braking and directional control are almost nil." The chapter also contains an interesting and easy mathematical formula to determine the minimum speed at which dynamic hydroplaning could occur. To use it you will need to know your aircraft's tire pressure.

Landing during or shortly after a rainstorm should make any pilot alert to potential hydroplaning. Standing water or puddles on a runway are other warning signs. Grooved runways minimize the problem by facilitating drainage. Check the runway surface of your destination as part of your flight planning. The possibility of dynamic hydroplaning is another incentive to make your landings to exacting standards of directional control and touchdown airspeed. Note that if hydroplaning begins, it may continue down a speed lower than the one determined by the formula referred to above. Numerous accidents in which aircraft have run off the end of grass runways have been attributed to excessive speed and dynamic hydroplaning-so keep this in mind when landing on a soft field. "By their nature, soft-field landings invite hydroplaning when wheels touch down on wet grass or soggy runways," advised Dave Wilkerson in "Checkride: Soft Touch" in the May 2001 AOPA Flight Training.

Dynamic hydroplaning is a risk for any size aircraft. Sharing one pilot's recollection could spare you a similar experience. "I knew lots of fancy terms for the problem and could quote the details from memory. It never made much of an impression on me until I experienced that no-brakes feeling as we were rolling out after landing an airliner on Runway 5R at Mexico City," AOPA Flight Training contributor Karen Kahn wrote in her April 2003 feature "Learn By Doing: Every Flight Helps to Build Good Judgment." Dynamic hydroplaning is another reason to make every landing your best landing.

My ePilot - Student Interest, Training Products
CALCULATE THAT LOAD WITH WEIGHT-AND-BALANCE SOFTWARE
Weight-and-balance software programs abound; you might even have a home-brew model conjured up in Microsoft Excel. But if you don't, Momentum Interactive's Weight & Balance Visualizer Computer offers a clean design and good graphics in a product available for many popular models of general aviation aircraft. The base program gives you one module with the aircraft model of your choice; you download the program from the company's Web site. Easy to download and straightforward to use, the program illustrates the center-of-gravity position on a two-dimensional image of the aircraft, with graphics for passengers, baggage, and fuel on board. Warnings pop when loading is out of range or over maximum gross weight. The initial program and module are $24.99; additional aircraft modules are $9.99. See the Web site for more information or to order.

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.

My ePilot - Student Interest, Final Exam
Question: My instructor and I have been reviewing sectional charts and symbols. What is meant by the rectangular-shaped, magenta dashed line that extends from certain airports?

Answer: The magenta dashed line depicts Class E airspace that extends down to the surface. This allows aircraft flying an instrument approach procedure to that airport to remain in controlled airspace during the descent. The Aeronautical Chart User's Guide shows the many ways Class E airspace can be depicted on sectional charts. You'll find more helpful information in the AOPA Air Safety Foundation's publication Airspace For Everyone .