National Geographic : 1931 May
FLYING THE "HUMP" OF THE ANDES BY CAPT. ALBERT W. STEVENS United States Army Air Corps AERIAL PHOTOGRAPHER, NATIONAL GEOGRAPHIC SOCIETY LATIN AMERICA AIR SURVEY, AUTHOR OP "EXPLORING THE VALLEY OF THE AMAZON," IN THE NATIONAL GEOGRAPHIC MAGAZINE With Illustrationsfrom Photographsby the Author, with the Cooperationof the Argentine Army Air Corps, Chilean Army Air Corps, and Pan American-Grace Airways UNTIL recently, if I had been invited to participate in a transatlantic flight I would have firmly refused. Every thing is relative. And now, after a certain flight, late in last October, across the Cum bre, south of Aconcagua, I would agree to cross the ocean half a dozen times rather than cross the Andes under the weather conditions that existed on that occasion. We got through, but what a trip ! Let me hasten to explain that the reg ular passenger on the South American air lines hasn't the remotest chance of getting mixed up in such a hair-raising business. When you get on a large air-liner at any of the modern airports between here and Buenos Aires, whether on the east coast or west coast, you have a feeling of security. But don't try to get permission to ride the plane that is used exclusively for mail and company employees across the Andes, for no guarantee whatever will be given you. The mail must go,* and it gets through usually on the first attempt; but on those occasions when the pilot is forced back for more fuel after hours of battling for an opening between crags and clouds, you may be sure that you would never have enjoyed being with him. FLYING THE "HUMP" IS AVIATION'S HARDEST RUN When the assertion is made that flying the "hump," as the Cumbre is called, is the hardest run in aviation, one has in mind the fog-enshrouded ridges of the Alleghenies, the blizzard-swept passes of the Cascades, the Sierra Nevadas, and the Rockies. Us pallata Pass, with the Cumbre as the divide, has, on occasion, on a single flight, every thing that is known elsewhere in the * See, in the NATIONAL GEOGRAPHIC MAGAZINE, "Flying the World's Longest Air-Mail Route," by Junius B. Wood, and "On the Trail of the Air Mail," by J. Parker Van Zandt, for March, 1930, and January, 1926, respectively. weather line-fog, clouds, rain, hail, snow, thin air, cold air, and terrific wind currents. A hundred miles to the south is a some what easier pass, the Paso de Maipu, lo cated on the southern side of the huge ex tinct volcano of the same name. This pass is more than a thousand feet lower than the Cumbre, and its approaches are more gradual on each side of the divide; yet this pass has claimed its first mail plane, for last July the French aviator Guillemet was caught in descending air currents in a snowstorm and forced into the basin of the Laguna del Diamante, where he cruised vainly round and round until forced to land near the ice- and snow-covered shore of the lake. The plane turned over, but Guillemet was unhurt. For more than four days and nights he plodded doggedly through the lonely, wind-swept canyons, finally reach ing shelter and food at the hut of a sheep herder. He had a very narrow escape from death by exposure. Four times a week the Americans fly the Andes, largely by the northern route of the Cumbre, or Uspallata Pass, except when weather conditions permit them to make a high- altitude, direct- line flight between Santiago and Mendoza. Twice a week the French cross with mail, using the southern route. It would be idle to try to compare the ability of the various pilots; all of them must be unusually capable, and they more than earn the high wages that prevail. SAN MARTIN'S VICTORIOUS ARMY ENTERED CHILE BY USPALLATA PASS Uspallata Pass, though higher, is a shorter route between the capital of Chile and the wine center of western Argentina. It was through this pass (pages 602-5 -9), over a century ago, that San Martin de scended into Chile with four thousand soldiers to deal the Spanish forces a blow from which they never recovered.