290 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1944 
motored planes are fitted with so-called “communicators,” rendering 
it possible to warm one motor by the action of another. 
The greatest obstacle to Arctic flying is poor visibility due to low- » 
lying clouds and fog. In the 46-hour flight of the Worge from King’s 
Bay (Spitsbergen) via the North Pole to the northern coast in Alaska, 
16 hours—or about 35 percent of the time—were spent in fog. Such 
fog is a common occurrence in the polar regions, especially where 
warm air, inflowing from lower latitudes over open water, meets cold 
air over pack ice or glacier-covered land, as is the case in Arctic areas 
during the summer months. Almost all floating ice is said to be ac- 
companied by fog, but when the ice is firmly attached to land, as it 
is in the wintertime, the atmosphere is relatively free from fog. 
Fog therefore seems to be a seasonal problem, but it does appear in 
winter in the region of the Bering Sea and the Aleutian Islands, where 
the warm Japan Current enters the Arctic, and along the southern 
edge of the Arctic pack north of Europe where the warm Gulf Stream 
encounters it. 
But fog in the Arctic is less dense and lower lying than it is else- 
where. Since it seldom rises to a height of over 3,000 feet, planes 
can fly over it with little difficulty. It is also thin so that planes 
can cruise at low altitudes, and because there are no obstacles like 
mountains, except over landed areas such as Greenland, Spitsbergen, 
and parts of Alaska and Siberia, the Arctic pilot can see through the 
fog and still retain sufficient horizontal vision. When Arctic areas 
are properly mapped and a greater number of radio stations are in 
operation to give reliable bearings to the polar flyer at all points 
along his route, it will no longer be necessary to fly by rivers and other 
landmarks, as is now the case. 
Opinion seems to be somewhat divided as to whether dependable 
regular and emergency landing facilities are available in the polar 
regions. On the one hand, it is believed that Arctic waters provide 
dangerous landing fields, for, although the water’s surface often 
appears clear from above, it may be filled with small lumps of par- 
tially submerged ice which can easily wreck a plane as it tries to 
land. Because of the movement of’ Arctic ice, moreover, openings 
fail to remain open, so that a plane, as it alights upon the water, 
may rapidly be hemmed in and crushed by the ice. In the summer 
months driftwood also endangers an attempt to land upon the surface 
of the water. 
As far as landing upon the pack ice is concerned, it is estimated 
that perhaps 90 percent of this surface is too rough to be used suc- 
cessfully, although there occasionally are some stretches of level 
ice upon which a plane may safely alight. But even if the landing 
is achieved without mishap, it frequently is more hazardous to take 
ee 
