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AOPA Online Members Only -- AOPA ePilot Custom Content -- Vol. 9, Issue 21AOPA Online Members Only -- AOPA ePilot Custom Content -- Vol. 9, Issue 21

The following stories from the May 25, 2007, 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.

My ePilot – Student Interest, Training Tips
For pilots of aircraft with carbureted engines, one hazard can escape detection because the conditions in which it can occur seem so innocent. The result is easily avoidable accidents, and the culprit is carburetor icing. Conditions that favor it can include outside air temperatures of up to 100 degrees Fahrenheit.

Suspect carburetor icing (described in the August 23, 2002, Training Tips) if a carbureted engine runs rough at reduced power settings or in warm, humid conditions. "Carburetor ice is most likely to occur when temperatures are below 70 degrees F (21 degrees C) and the relative humidity is above 80 percent. However, due to the sudden cooling that takes place in the carburetor, icing can occur even with temperatures as high as 100 degrees F (38 degrees C) and humidity as low as 50 percent," according to Chapter 5 of the Pilot's Handbook of Aeronautical Knowledge. See the table of conditions under which carburetor ice is likely to form.

Numerous pilots have learned about this risk the hard way. A good example is found in a Never Again Online report of an accident that befell a pilot with his family on board his Cessna 182. Summing up the event, he writes, "The FAA, after exhausting all other possibilities, concluded that carburetor icing was the culprit. In fact, conditions were ideal for it that day."

Note the pilot's reflections on having been fixated on his fuel supply when the problems began: "Because I had put blinders on to any other source of the problem, I never considered carb ice to be a factor. In fact, I contributed to ice formation by pulling back on the power for a slow descent from altitude to conserve fuel after leaving Fort Wayne, and contributed further by pulling power when trying to lose altitude when trying to get down to the grass strip."

What conditions favor carburetor ice in your aircraft? How should your carb heat be applied to prevent or eliminate it? Improper use can be dangerous; see the "Instructor Report" in the October 2006 AOPA Flight Training. Then, be ready to fight carb ice when you head off into the humid warm air of spring and summer.

My ePilot – Training Product
Digital Cyclone, which is now a subsidiary of Garmin Ltd., offers a new version of its Pilot My-Cast cellular-phone application that gives pilots a fast and easy way to file a flight plan while on the go using a mobile phone. Pilot My-Cast is a cellular-phone service that gives pilots personalized flight planning and weather information, including textual weather reports and radar graphics. Version 5 is the latest version of the software available; the application is compatible with most major national wireless providers and cellular phones. The service is $12.95 per month plus a $9.95 set-up fee or $129.95 annually. For more information, see the Web site.

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: I've heard of a visual illusion that I might experience while flying at night called "autokinesis." Can you tell me what it is and how to deal with it?

Answer: Autokinesis is one of three primary nighttime visual illusions (the other two are the perception of a false horizon and night landing illusions). If you stare at a single point of light against a dark background for more than a few seconds, the light will appear to move. This false perception of movement is called "autokinesis." To prevent this illusion, focus the eyes on objects at varying distances and avoid fixating on any one object for too long. For more insight into night flying illusions, take a look at the article, "Learning Experiences: Seeing is believing," and the subject report, "Night Flying."

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