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The following stories from the September 19, 2008, 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 Training Tips

While studying the features of an airport to which you have planned a cross-country, or examining the amenities of your home field, you observe that one or more runways are served by approach slope indicator systems. These systems offer a pilot flying the final approach the added dimension of vertical guidance to a safe touchdown. See the June 13, 2003, " Training Tip: Glidepath Guidance."

Make it your business to become thoroughly familiar with how to use vertical guidance systems—and to know where they're available. At certain times, such as during deteriorating weather or a night landing, vertical aid can provide a big boost to safety. In conditions of calm winds, choose a runway served by a vertical guidance system at a nontowered airport. "A safe bet is to plan a steep approach, within your skills and your airplane's capabilities, to grant you extra assurance that you have a clear path down. If you have a choice of runways, pick one with a visual approach slope indicator (VASI) or precision approach path indicator (PAPI), some kind of illuminated tool to help you determine the glide path," wrote Julie K. Boatman in the March 2004 AOPA Pilot feature " Black Holes." Even at a towered airport, you may have that option if the controller clears you to land and says, "Wind calm, your choice of runways." Seize the opportunity—especially if the landing must be accomplished at dusk or in darkness.

Some student pilots assume that such technology as vertical guidance systems are only for use by instrument pilots emerging from clouds, or by pilots at a more advanced level of training than applicants for a light sport or private pilot certificate. Not so! Indeed, a longstanding FAA advisory circular recommends that "all student pilots be introduced early in their flight training to the use of any available approach slope indicator, and taught to use it regularly in planning standard, uniform landing approaches."

Clearly then, your knowledge of vertical guidance systems could be the subject of oral quizzing on a flight test. And surely your designated examiner will observe whether you are attempting to remain at or above the approach path of any VASI- or PAPI-equipped runways on which you may be asked to land.

Training Products

To get from point A to point B, you've got to know how to navigate there. Navigational practices have changed in the past five years. Some systems have disappeared, some are less important, and some are much more important. Donald J. Clausing's Aviator's Guide to Navigation has been revised and updated to include glass-cockpit navigation. The book sells for $34.99 and is available from

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 Final Exam

Question: I know the maximum elevation figures (MEF) depicted on a sectional chart show the highest terrain and/or obstacles within a quadrant, but can you tell me how the MEF is calculated?

Answer: For man-made obstacles taller than 200 feet, the MEF is calculated by determining the elevation of the top of the obstacle above mean sea level (msl). Then, additional height is added according to a cartography formula to cover a possible vertical error. Finally, the figure is rounded up to the next highest 100-foot increment. For example, if the highest man-made obstacle within a sector is 2,250 feet msl, 100 feet would be added to cover a possible vertical error (2,350 feet). This figure would then be rounded up to the nearest 100 feet and be charted as a 2,400-foot MEF for that sector. A similar process is used for calculating the MEF for terrain or natural obstacles, except that an additional 200 feet is added just in case there is a man-made obstacle on that terrain that wasn't charted because it is less than 200 feet tall. Learn more in the AOPA Air Safety Foundation's Safety Hot Spot, NACO Aeronautical Chart User's Guide .

Got a question for our technical services staff? E-mail to [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.

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