Page:CAB Accident Report, United Airlines Flight 16.pdf/12

 airplane and its component parts. There are no accessories changed at this time unless they are found to be malfunctioning. The number three check is performed after about 100 to 125 hours of flight time and in addition to all the work which is required to be done in the number one and number two checks, the spark plugs are changed, the main oil screens are checked, the landing wheels are removed, disassembled and inspected, floor boards are removed from the companionway, and the control cables are inspected. The record contains reports of all the checks which were made of aircraft NC 16086 during the last 95 hours preceding the accident. From these records it appears that all of the required inspections and checks were made and that only a few minor deficiencies were noted and those were promptly remedied.

United also requires its flight personnel to file, at the end of each trip, a trip log upon which they insert any comments they may have as to the operation of the aircraft, engines, instruments, and radio. The record includes trip logs for the last ten trips made by NC 16086 and they contain only a few minor criticisms made by the pilots on the operation of the engines and it appears that the necessary adjustments to eliminate these deficiencies were promptly made. No criticisms were made of the performance of the aircraft, engines, instruments, or radio on the flight which was made by the airplane from Oakland to Los Angeles and return on November 3, 1940, which terminated just a short time prior to the take-off of the airplane for Salt Lake City. In addition, a number two check had been given the airplane just prior to its departure from Oakland for Salt Lake City on November 3 and the report of this inspection indicates that the airplane and its equipment were in proper condition at the conclusion of the inspection.

Thus, from all the evidence available to us, we find that the airplane