The following stories from the February 22, 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 – Student Interest, Training Tips
TERM REVIEW: CORIOLIS
The Feb. 15 "Training Tip" pointed out that pilots can get an accurate big-picture idea about winds before a flight by reviewing the distribution of isobars around low- and high-pressure areas on a surface analysis chart. Add in other factors, including the Coriolis force, and more detail about winds emerges.
"Explain the Coriolis force," a designated pilot examiner might ask an applicant for a private pilot or sport pilot flight test. There are also several questions that could appear on your knowledge test that include the Coriolis force in answers. Are you up to the challenge of defining this term? And why is Coriolis spelled with a capital C?
"The turning of wind, and other things such as ocean currents, in relation to the Earth as a result of Earth's rotation is called the Coriolis force after Gustave-Gaspard Coriolis, a French scientist who in 1835 first described mathematically how this works," explained meteorologist Jack Williams in his December 2005 AOPA Flight Training column "The Weather Never Sleeps: Pressure Situation." Take a moment to inspect the article's illustrations of this concept.
The deflective effects of Coriolis force are stronger near the poles than near the equator, where it diminishes to zero. And they act more strongly "with the speed of the moving body," explains an in-depth discussion of Coriolis found in Chapter 10 of the Pilot's Handbook of Aeronautical Knowledge. Note the explanation of how, within 2,000 feet of the surface, friction reduces Coriolis force—part of the reason the wind direction varies somewhat from that found just a few thousand feet higher. That's the kind of information that will enable you to give a correct answer to the following sample knowledge test question:
The wind at 5,000 feet agl is southwesterly while the surface wind is southerly. This difference in direction is primarily due to
A) stronger pressure gradient at higher altitudes.
B) friction between the wind and the surface.
C) stronger Coriolis force at the surface.
Given the hint provided above, which answer is best? Pick one and see if your instructor agrees! Or send an e-mail or call AOPA's in-house aviation experts at 800/USA-AOPA to see if you picked the correct answer.
My ePilot – Training Product
EXPLORE RARE AIRCRAFT WITH BARRY SCHIFF'S 'DREAM AIRCRAFT'
When the weather's too poor to fly, a good book about airplanes can be the next best thing. And for those who covet unique or unusual airplanes, AOPA Pilot columnist Barry Schiff has the prescription. His latest book, Dream Aircraft, includes pilot reports and photography for 33 rare and unusual airplanes. If you've wondered what it's like to pilot a Culver Cadet, an Antonov AN-2, a P-51D Mustang, or even the space shuttle, Schiff's book will give you the details. The soft-cover, 328-page book sells for $19.95 and can be ordered from Aviation Supplies and Academics, Inc..
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: How many different types of special-use airspace are there?
Answer: There are 13 different types and variations of special-use airspace (SUA) that you might be exposed to throughout your flying career. Of the 13, seven are the most visible within the National Airspace System—temporary flight restrictions (issued by FAA notam), prohibited areas, restricted areas, warning areas, military operations areas, alert areas, and controlled firing areas. SUA exists where activities must be confined because of their nature, and limitations may be placed on aircraft that are not part of the planned activities. While performing your preflight planning pay particular attention to your course line as it makes its way from waypoint to waypoint. Consider making a marked notation on your chart(s) of any SUA that your route will traverse [see the FAA's online listing of SUA]. Additional insight and knowledge can be gained by taking the AOPA Air Safety Foundation's online course, Mission Possible: Navigating Today's Special Use Airspace.
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.