פורסם עם: General Aviation

N ew season, new decisions

Fall flying conditions have taken root. In northern regions and at higher elevations far to the south, chilly temperatures—even snow—have made their seasonal debut. Flying in fall is glorious. But to do so with precision and safety, make some necessary mental adjustments, both for flight planning purposes and to recalibrate your safety margins.

For student pilots who began training in spring or summer, chilly mornings of fall will become your introduction to frost. Even if you have read about the aerodynamic hazards of attempting to fly an airplane with frost-coated wings and control surfaces, don't go it alone when you remove frost from your training airplane for the first time on the morning of a scheduled sun-up solo flight. Get assistance, or have a veteran check your work. The Jan. 17, 2003, Training Tip discusses frost in detail and provides links to articles and regulations helpful to review.

With outside air temperatures falling, your performance calculations need to reflect reality, so make sure to review your performance charts and adjust your selections of power and altitude to the right values for the desired fuel burns and true airspeeds. Don't be casual about this: A Cessna 152 cruising at 6,000 feet at 2,300 rpm burns three-tenths of a gallon more per hour when temps are 20 degrees below standard than when cruising at standard temperature. The wind and temperatures aloft forecasts (FDs) that you'll need to scrutinize are described in Chapter 11 of the Pilot's Handbook of Aeronautical Knowledge. It's also time to track the lowering altitude of the freezing level, which is the subject of the Nov. 26, 2004, Training Tip. This is especially important if precipitation is possible.

For flights scheduled to begin late in the day, use night fuel reserves as a baseline in your flight planning. Carry flashlights and plan to land with at least one hour of fuel remaining, as recommended by the AOPA Air Safety Foundation's Fuel AwarenessSafety Advisor. Any time a delayed mid-afternoon flight seems to be losing its margin for being completed in the available daylight, reschedule or turn around rather than flirt with trouble!