AOPA Online Members Only -- AOPA ePilot Custom Content --Vol. 6, Issue 10

November 11, 2009



The following stories from the March 5, 2004, edition of AOPA ePilot were provided to AOPA members who expressed an interest in the particular subject areas. Any AOPA member can receive information customized to their areas of interest by updating their member record file online.



My ePilot - Student Interest, Training Tips
WINDS OF CHANGE
Pilots sometimes must move between different measuring systems when making flight calculations. Wind speeds are given in knots (nautical miles per hour), but some older aircraft performance charts and airspeed indicators use miles per hour, requiring conversion. Temperatures in aviation weather observations are reported using the Celsius scale; temps that you heard on the radio this morning were probably degrees Fahrenheit. During flight planning you draw a course line on an aeronautical chart. This is a true course. After winds aloft, magnetic variation-see "Flying Smart" in the March 1999 AOPA Flight Training-and compass deviation are applied, you get a magnetic course for selecting a cruise altitude, a magnetic heading, and a compass heading that negates any instrument inaccuracies. Remember that cruise altitude is dictated by the hemispherical rule, discussed in the February 7, 2003 Training Tips in this newsletter.

The coverage areas for winds aloft forecasts are large, encompassing regions of differing variation-see them on a clickable National Weather Service map. This requires that wind directions be forecast relative to true north. Not so of all winds pilots need. As you near your destination, you monitor the Automatic Terminal Information Service (ATIS) or an automated weather reporting station. What will you hear? "ATIS information includes the time of the latest weather sequence, ceiling, visibility, obstructions to visibility, temperature, dew point (if available), wind direction (magnetic) and velocity, altimeter, other pertinent remarks, instrument approach and runway in use," explains the Aeronautical Information Manual . These winds are magnetic because runways are numbered according to their magnetic bearings, making it easy to compare values and note crosswind components.

So, surface winds are magnetic and winds aloft are true? Almost, but there's a catch. Those magnetic surface winds on ATIS, or given by a tower controller, appear as "true" winds in aerodrome forecasts (TAFs) and aviation weather reports (METAR, SPECI).

Confusing? Columnist Rod Machado, in the February 2004 AOPA Flight Training, offers this suggestion: "Here's a memory cue offered with no disrespect to our ATC buddies: Controllers speak of winds with forked tongue (i.e., they don't give you the "true" winds)."

The idea to remember is that when you need wind information most-at takeoff or landing-don't convert what you hear. That's been done for you so that you can focus on your flying.

My ePilot - Student Interest, Training Products
ASA's FLIGHTLIGHT PEN PRESERVES NIGHT VISION
Night fliers and student pilots who have begun their night training know the importance of preserving "night vision"-allowing your eyes to adapt to low-light conditions, and making sure you don't compromise that by suddenly exposing your eyes to a bright light. How do you jot down a note or ATC direction during a night flight? You could use a Flightlight Pen from Aviation Supplies and Academics. Twist the end to activate a green light-emitting diode (LED) in the ballpoint; use the flashlight cap to look for nearby items. The pen is $6.95 and comes with two LED lights and two button-cell batteries. Order it online from ASA.

My ePilot - Student Interest, Final Exam
Question: I have found what I think is a mistake on a sectional chart. How can I report this to get it corrected?

Answer: A note in a box on your sectional chart describes what you should do. The FAA's National Aeronautical Charting Office (NACO) would appreciate receiving the information. Postage-paid correction cards are available from authorized chart sales agents. Where detailed written or drawn data is required, note the information clearly and accurately on a current chart (NACO will replace the chart) and mail it to FAA, National Aeronautical Charting Office, AVN-510, SSMC4, Station #2335, 1305 East West Highway, Silver Spring, MD 20910-3281; telephone 800/626-3677; or e-mail.