384 POLAR PROBLEMS 



Take-Off and Landing Fields 



It is difficult to find long, level stretches of snow on land in the 

 Arctic, from which a plane can take off with a heavy load, without 

 first leveling and packing the snow. The take-off field should be at 

 least a mile long. The smoothest places are frequently wavy and 

 bumpy. The "bumps" slow up the plane and render it difficult to 

 attain flying speed. For a plane with a light load, the snow, if it is 

 ordinarily firm, need not be packed. 



Landings, however, can be made on the smoother stretches of un- 

 prepared snow. They should not be made on rolling soft snow, for 

 this tends to stop the plane in a short distance. In the case of taking 

 off with a heavy load, it is sometimes advisable to ice the snow im- 

 mediately in front of the skis for the initial start. 



Best Season for Arctic Flying 



Of course, weather conditions vary from year to year locally as well 

 as for places in the same latitudinal climatic belt; but, generally speak- 

 ing, the best flying conditions in the Arctic seem to prevail during the 

 months of April and May. During these months there is plenty of firm 

 snow covering the land and ice that is suitable for a take-off with skis. 

 If the season in the locality in question is far advanced, the snow will 

 probably begin to soften in the latter part of May, and that condition 

 will, of course, cut down the load that the plane can take off the snow 

 with skis. Generally speaking, of course, the farther from the pole 

 the earlier the snow will become soft. In 1925, in Spitsbergen, the 

 snow on the land and ice was firm as late as May 24, whereas in 1926 

 the snow had begun to soften by May 14. In Alaska in 1926 the snow 

 began to soften during the first part of May. 



There is another great advantage of flying in April and May, 

 namely, the freedom from fog — the airplane's great enemy. Of course, 

 fog conditions vary from year to year and are not the same throughout 

 a given latitude, but generally fogs are worse during the summer 

 months than during the spring months. For example, fog is rare at 

 Etah and Spitsbergen the first two weeks in May. After that there 

 may be fog at both places, but more at Spitsbergen — due to the in- 

 fluence of the Gulf Stream. Fog is likely to be a handicap in Alaska 

 beginning the latter part of Ma3\ 



It is not generally practicable to use skis in the autumn because 

 there is not sufficient snow. However, if the explorer decides to fly 

 from the snow with skis in the spring, starting anywhere north of 

 latitude 78°, he must winter in the Arctic, unless he chooses Spits- 

 bergen, which is generally opened up in spring by the Gulf Stream. 

 Etah, North Greenland, or Point Barrow, Alaska, cannot be reached 

 by steamer until July or August. 



