Page:CAB Accident Report, United Airlines Flight 21.pdf/61

 Mr. Becker, who has been a control tower operator at the Chicago Municipal Airport for over 7 years, went on duty at 5:20 the afternoon of the accident but testified that he had been in the control tower for some time prior to the beginning of his tour of duty. During his contacts with United 21, he gave the trip the alternative of landing on the east-west runway or the northwest runway, having instructed the flight in the first instance to land northwest but later supplementing that instruction with the statement that the trip might land west "if you have a lot of ice and wish to land west."

The operation of the municipal control tower with respect to United 21 appears to have been adequate with one possible exception. The record indicates that none of the incoming aircraft was advised of the slippery condition of the runways. Although Mr. Becker testified that it was customary to advise incoming traffic of the condition of the runways, he stated that at that time he did not know or believe that the runways were slippery. In this connection, Captain Richmond testified that the runways at the time he landed about 4 p.m. were not slippery but that when taxying just prior to the accident, he observed that the runways had become extremely slippery. The testimony of ground observers as to the condition of the ramps and other pavements near the airport is conflicting, but Captain Richmond's testimony with respect to the slippery state of the runways is confirmed by other pilots who landed within a short time before and after the crash. This condition should have been known to the airport control tower operator and given to all pilots to whom he gave landing instructions. The testimony indicates that the runways had had snow on them for several days and that on the evening in question a wet snow or freezing drizzle was falling. These conditions should have warned him that in all likelihood the runways were slippery,