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IFR Fix: It's freezing in hereIFR Fix: It's freezing in here

Whenever an inactive instrument pilot showed up at the flight school to brush up the skills, it was a good bet that weather interpretation made for productive ground review, and unusual-attitude recoveries needed attention in flight.

Photo by Mike Fizer.

If you are ready for some similar work, selected questions from a recent FAA sample instrument-rating knowledge test make a good launching pad for getting back into an instrument-flying frame of mind by hitting details worth recalling some icy or cloudy or windy winter day.

Speaking of clouds that make ice, suppose you are at an elevation of 1,350 feet msl and the temperature is 8 degrees Celsius. Where’s the approximate freezing level (assuming an average temperature lapse rate)?

The instrument rating knowledge test presents this as a multiple-choice question, but I don’t have to play by those rules. If you’ve cogitated a while and are drawing a blank, here’s a great big hint from the Pilot’s Handbook of Aeronautical Knowledge: “A standard temperature lapse rate is when the temperature decreases at the rate of approximately 3.5 °F or 2 °C per thousand feet up to 36,000 feet, which is approximately –65 °F or –55 °C.”

Another question from the test asks: What is an important characteristic of wind shear?
A) It is an atmospheric condition that is associated exclusively with zones of convergence.
B) The Coriolis phenomenon in both high and low level air masses is the principal generating force.
C) It is an atmospheric condition that may be associated with a low level temperature inversion, a jet stream, or a frontal zone.

I agree it can’t hurt to refresh on convergence zones and Coriolis force, but please remember that “low-level wind shear is commonly associated with passing frontal systems, thunderstorms, temperature inversions, and strong upper level winds (greater than 25 knots),” and can be dangerous.

You can’t practice unusual attitude recoveries on a knowledge test, but you can arm yourself with knowledge to help you prepare, in case icing or wind shear or other causes serve one up in flight. For starters, try answering this question:

“In addition to the attitude indicator, the pitch control instruments are the
A) altimeter and airspeed indicator.
B) altimeter, turn coordinator, and VSI.
C) altimeter, airspeed indicator, and VSI.”

Consulting the PHAK on pitch control turns up this excerpt which explains that the pitch instruments “include the attitude indicator, altimeter, VSI, and airspeed indicator.”

For pilots of glass-cockpit-equipped aircraft, a separate chapter discusses using that technology.

Dan Namowitz

Dan Namowitz

Associate Editor Web
Associate Editor Web Dan Namowitz has been writing for AOPA in a variety of capacities since 1991. He has been a flight instructor since 1990 and is a 30-year AOPA member.
Topics: Weather, IFR, Weather

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