Proficient Pilot

Going polar

September 1, 2010

Every airline pilot has his favorite flight segments. Domestically, mine was the route between Los Angeles and Denver (or vice versa). On a clear day, the scenery is nothing short of spectacular.

Heading east from over Las Vegas, we would first dip a wingtip toward Boulder Dam and then—with ATC approval—deviate toward the Grand Canyon where we’d make S-turns over this geological wonder, a maneuver known to ATC as the “canyon tour.” From there it was a few minutes northeast to Lake Powell, where Planet of the Apes was filmed. Many narrow and twisted canyons are carved along the red-rock topography, and the lake has almost 2,000 miles of shoreline. A slight jog right put us over Monument Valley, characterized by remnant cores of ancient volcanoes that rise dramatically from the desert floor, the heart and soul of the Navajo Nation. We’d cross the goosenecks of the San Juan River and begin our descent over the snow-capped Rockies.

It seemed at times that I babbled more over the public-address system than over the radio. There was so much to show. When jet fuel was cheap (about 20 cents per gallon) we’d fly lower than usual to increase detail and color. Despite the extra miles, added flight time seldom exceeded a few minutes, and the passengers loved their guided tour of the Southwest.

Internationally, my favorite leg was the polar flight from London to Los Angeles. A flight in the opposite direction was mostly at night, and there was little to see except an occasional and daunting display of the northern lights. The polar route, an aerial Northwest Passage of sorts, was inaugurated in 1954 by SAS (Scandinavian Airlines System). Prior to this, flying from the U.S. West Coast to Europe necessitated an en route stop in New York or some such place. Time en route for the journey using Douglas DC–6Bs was almost 30 hours (including time on the ground). But flying a nonstop great circle route slashed the distance by a thousand miles and decreased flying time to only 16 hours. The same flight today takes only about 11 hours.

Overflying Iceland, Greenland, and northeast Canada on a clear day reveals some of the most beautiful scenery in the world. One never tires of gazing at the fearsome beauty passing below. It is tranquil, almost inviting, yet we know well what it would be like to have to survive a forced landing in such a region.

One rule is to stay put. To abandon the relative comfort of a wrecked aircraft in blind search of assistance is risky. A man attempting to walk a straight line in the white waste without an aiming point will instead walk a large circle in the direction of his shorter leg.

I once landed at Thule Air Force Base on the extreme northwest coast of Greenland. It was as cold there as I have ever been. A mechanic climbed aboard the aircraft, tried to shake off the cold, and asked if we had a hot dog. We did, and I gave him one. The guy must really be hungry, I thought. He then said, “Watch this.” He threw the warm frankfurter spinning out the front door and on a high trajectory. When the hot dog finally hit the tarmac, it broke into what seemed like a hundred pieces. It had frozen solid and had become brittle during its brief flight.

When SAS pioneered the polar route, there were no radio aids to navigation in the Arctic. Celestial navigation was the only way to determine position. But normal celestial navigation is impossible during the lengthy periods of Arctic twilight that occur twice a year as the seasons change between summer and winter. During such twilight, there are no heavenly bodies to be seen. No stars. No sun. Often no moon. Nothing. How, then, could a navigator get his bearings? The solution was the Kollsman Sky Compass. It worked on the principle of polarized light. Although the sun is below the horizon, its rays hit the zenith of the sky and are reflected to Earth in “ribbons.” These so-called ribbons are polarized—they travel only in one direction. By measuring the direction of these ribbons, the navigator could effectively “see” the sun even though it was below the horizon. The result was a solar line of position (SLOP).

Another problem was that the ordinary magnetic compass is worthless when within a thousand miles of the Magnetic North Pole (near Canada’s Resolute Island). The solution was a polar-path (gyroscopic) compass that a navigator (or pilot) could use to input latitude to compensate for precession otherwise caused by the Earth’s rotation.

Even with the introduction of GPS, soaring along a polar route between America’s West Coast and Europe is nothing short of fascinating.

Barry Schiff was awarded the Louis Blériot Medal in 1969 by the Fédération Aéronautique Internationale. Visit the author’s website.

Join the fun

Barry Schiff will be a featured speaker at the 2010 AOPA Aviation Summit. He will present “Engine Failure After Takeoff” on Saturday, November 12, and will co-host a “Dine Around” event on Thursday, November 11. See the website for more information.