EXPLORATION BY AIRSHIP 423 



path of the propeller blades, was hurled against the keel of the airship. 

 The perforation of the gas bag and of the covering of the keel might 

 have been the beginning of serious trouble. This danger had been fore- 

 seen but had not been taken care of completely. In the future it will 

 be possible to avoid it easily either by covering all outer metallic parts 

 with special grease or by protecting the propellers from the flying ice. 

 Of course, the best solution is to avoid flying in a layer of damp and 

 comparatively warm air. 



For airplanes there is the same danger of ice forming, but it is 

 certainly a relatively small matter. 



SNOWSTORMS 



Snowstorms may disturb aerial navigation in the Arctic. The 

 Russian experts were particularly worried about that, but our ex- 

 perience, although we passed through many snowstorms during our 

 flight from Russia to Alaska, was that they never gave us any trouble 

 at all. The snow had no time to stick to the keel of the airship, and 

 the wind carried away whatever small amount had a chance to deposit 

 itself mechanically over the gas bag. 



Protection of Motors and Gas Valves 

 Against Low Temperatures 



In Arctic exploration, besides taking into account the conse- 

 quences of fog, snow, and ice, it is also necessary to envisage the 

 dangers to which the vital parts of aircraft, namely, in the case of an 

 airship, the motors and the gas valves, are directly exposed as a result 

 of low temperatures. 



From this point of view, granted that the vital parts of a dirigible 

 are more numerous than those of an airplane, it is true that any trou- 

 ble can be taken care of much more easily on the former than on the 

 latter. For instance, during our flight one of our motors stopped fre- 

 quently on account of the formation of ice in the gasoline pipe. The 

 search for and repair of this trouble was not a small matter, and I have 

 no doubt that the same trouble would have obliged an airplane to make 

 a forced landing with all its consequences. 



As regards gas valves I wish to point out here our experience dur- 

 ing the World War. On many flights at that time we found out that 

 ice incrustations, formed when the valves were open, often made it 

 impossible for the valves to close tightly, with a consequent loss of 

 gas. That is why, during the preparation for the transpolar flight, 

 special care was given to the protection of the gas valves against the 

 formation of ice. Grease was used, and, for added security against 

 the outside humidity, we covered the valves with protective caps. 



