Page:CAB Accident Report, United Airlines Flight 21.pdf/35

 Of the eight airlines serving Chicago out of the Chicago Municipal Airport, only one, Chicago and Southern Air Lines, cancelled any of its operations during the afternoon of December 4 because of the weather conditions existing at Chicago. Several airline pilots who operated flights into and out of the Chicago Airport testified as to the weather conditions encountered by them.

Captain Lawrence H. Holsinger landed a United plane at 5:14 on a trip from New York to Chicago. This trip was in the overcast for a period of 25 minutes and Captain Holsinger estimated the overcast extended to within 600 feet above the ground with low-lying scud clouds at 400 feet. The visibility was approximately one mile and the wind was reported from the northwest with a velocity of 5 miles an hour. He landed on the west runway but said that with a higher wind velocity he might have used the northwest runway, although not estimating the minimum velocity which would determine his landing on that runway. While he encountered light ice all the time he was in the overcast, this ice appeared to melt off of his windshield as soon as he broke out under the overcast. Ice began to form in his carburetors about a mile from the field, disappearing on the application of carburetor heat. He estimated the temperature as a few degrees above freezing. The ship landed normally, showing no characteristics of icing, and on inspection on the ground just a few spots of rough ice remained clinging to his de-icer boots. He used his de-icing equipment while in the overcast, not shutting his boots off until he passed over the range station. The windshield de-icer worked effectively and on landing his windshield was free of ice. Captain Holsinger described the windshield de-icer used on United planes as a hot air blower equipped with a booster pump having two fixed outlets, one in front of each pilot.