DEPARTMENT OF COMMERCE
BUREAU OF AIR COMMERCE
Washington
REPORT OF THE ACCIDENT BOARD
BUREAU OF AIR COMMERCE
Statement of probable cause concerning an aircraft
accident which occurred to an airplane of United
Air Lines, Incorporated, at Western Springs, Illinois
on December 20, 1934
To the Director of Air Commerce.
On December 20, 1934 at approximately 6:15 p.m. at Western Springs, Illinois, an airplane of United States registry, piloted by licensed airmen while being operated in scheduled flight carrying mail and express, a crew of three and one other company employee, crashed with resultant serious injuries to the pilot, minor injuries to the copilot and major damage to the aircraft.
The airplane, a Boeing, model 247, bore Department of Commerce license number NC-13328 and was being operated between Chicago, Illinois, and Omaha, Nebraska, by United Air Lines, Incorporated. The pilot, David L. Behnoke, held a Department of Commerce transport pilot's license and a scheduled air transport rating. The copilot, Kenneth W. Quayle, held a Department of Commerce transport pilot's license. The stewardess, Barbara Berner, and John Wolfe, a company employee, were not injured.
The take-off from Chicago, Illinois, was accomplished at about 7:53 p.m. At this time the ceiling was established at 700 feet, visibility one and one-quarter miles and a light snow was falling. The weather was worse at Waterman, the next check point west of Chicago, but from Waterman on was very good.
After the airplane had flown on course for about fifteen minutes, the right engine slowed down, then stopped. The pilot circled to the left to return to Chicago and the copilot radioed Chicago of the fact and requested that the radio range beam be left on, which was done. About this time the left engine slowed down to the point that a forced landing was inevitable. During this time efforts were made by both pilot and copilot to keep the engines running.
The pilot headed south in an effort to land outside of the tower but was unsuccessful. The airplane came to rest at a 45° angle with the nose in some trees and the tail on the ground. The right engine was torn free of the airplane by the force of impact.
Investigation failed to disclose any malfunctioning of the aircraft or any mechanical failure of the engines. Both engines functioned satisfactorily through full throttle range when set up for test after the accident. The pilot states that all instruments registered normal conditions and that the carburetor heat controls had been fully on prior to the difficulty.
It is the opinion of the Accident Board that the probable cause of this accident was ice forming in the carburetors which resulted in loss of power.
Respectfully submitted,
ACCIDENT BOARD
Chief, Safety Section
Air Line Insp. Service
Manufacturing Inspection Service
This work is in the public domain in the United States because it is a work of the United States federal government (see 17 U.S.C. 105).
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