AOPA Online Members Only -- AOPA ePilot Custom Content -- Vol. 8, Issue 1

November 11, 2009



The following stories from the January 6, 2006, 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 - Turboprop Interest
BEECHCRAFT KING AIR C90GT RECEIVES FAA TYPE CERTIFICATION
Raytheon Aircraft Company received FAA type certification for its Beechcraft King Air C90GT on December 17. The twin-turbine aircraft flies and climbs faster and can take off in shorter distances than the King Air C90B that it is replacing. Pratt and Whitney PT6A-135 engines with 750 shaft horsepower give the C90GT a maximum cruise speed of 272 knots and a climb rate that allows the aircraft to reach its certified ceiling of 30,000 feet in only 22 minutes. A standard sea-level takeoff at maximum gross weight requires only 2,392 feet. The seven-passenger aircraft costs $2.95 million.

My ePilot - Student Interest, Training Tips
WINTER HIGHS
Winter is a challenging but rewarding time to fly. Icy ramps and cold-weather starts are the name of the game for those plucky pilots determined to keep their training moving ahead during the short, frigid days of January. Add careful airframe inspections for clinging frost, snow, or ice to your preflight procedures. Pay careful attention to notams about braking action reports on runways and ramps. And use special care to avoid "shock cooling" the powerplant when throttling back during descents and landings.

Cold weather also provides excellent opportunities to learn. The cold, dry air that characterizes winter high pressure systems lets normally aspirated engines generate maximum power. You will not have experienced this kind of climb performance on warmer weather flights. A large high passing through the region, or settling in for an extended visit, can provide welcome relief from the blustery routine-and opportunity. "The center of the high-the area with the highest barometric pressure and altimeter settings-has the shallowest pressure gradients, and this has a very important effect. Namely, surface winds calm down. Now is the time to practice those takeoffs and landings without the hassle of gusty crosswinds," Thomas A. Horne said in the July 2004 AOPA Pilot column "Wx Watch: History of a High."

A rare condition caused by winter highs is extreme barometric pressure readings that can challenge the capacity of your on-board instruments to measure it. What then? "Cold, dry air masses may produce barometric pressures in excess of 31 inches of mercury, and many altimeters do not have an accurate means of being adjusted for settings of these levels. When the altimeter cannot be set to the higher pressure setting, the aircraft actual altitude will be higher than the altimeter indicates," explains Chapter 7 of the Aeronautical Information Manual. See the chapter for air traffic control procedures during these conditions. And remember, as pressure systems come and go-emphasized in the AOPA Pilot article "Current Altimeter Settings Really Matter"-update your altimeter setting frequently to the value reported by ATC and flight service. It's a matter of good practice and safety.

My ePilot - Student Interest, Training Products
COMPANY OFFERS ONLINE KNOWLEDGE TEST PREP
Looking for an online method to prep for an upcoming sport, private, or commercial pilot knowledge test? Preparetotest.com offers a Web site to help you get the job done. Log in and access the pertinent exam from any Internet-based computer. The site lets you customize how and what part of the test bank is presented, and each question gives you access to an online E6B and calculator, and accompanying graphic, if applicable. Subscription levels start at $2.95 and are priced according to how close you are to taking the exam. For more information or to try a demo of the sport or private pilot exams, 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'm having difficulty decoding the winds and temperatures aloft forecast (FD). Can you help me?

Answer: Absolutely. Advisory Circular 00-45E, Section 4 provides the details behind the winds and temperatures aloft forecast. There is a six-digit group for each station at a given altitude; we'll use 821205 as an example. The first two digits, usually ranging 01-36, represent the wind direction in reference to true north, given in tens of degrees. If the numbers range from 51-86, indicating a wind speed greater than 100 knots, subtract 50 to determine the wind direction. You would add 100 to the second two digits, which indicate the wind speed in knots. Using the example, 82-50=32, giving a wind direction of 320 degrees and 100+12=112 kt. The last two digits indicate the temperature in degrees Celsius. The temperature in the example would be 5 degrees Celsius. You will note that some lower-level wind groups omit the temperature. Temperatures that are negative will have a minus sign displayed prior to the two digits, unless the altitude is above 24,000 feet where all temperatures are negative. See AOPA Online for the current winds and temperatures aloft forecast and other aviation weather products provided by Meteorlogix.