After the preliminary examination of the wreckage at the scene of the accident, the engines were shipped to Northwest's shop at Minnesota where a tear-down inspection was made. This inspection was supervised by an air safety investigator of the board. No indication was found of any malfunctioning of either engine prior to impact.
Examination of the propellers revealed a pitch setting of approximately 18° and that the variable pitch mechanisms were functioning properly.
The National Bureau of Standards made an examination of the left brake mechanism and found that it was probably in operative condition until the left under carriage was damaged by impact. The right brake mechanism was so severely damaged by fire that nothing could be detected by examination.
There was no indication that the aircraft or its accessories were not functioning properly at the time of landing.
CONDUCT OF FLIGHT
The evidence indicates that the trip was properly dispatched and that its operation was normal until it arrived in the vicinity of Miles City. It is also clear from the evidence that the radio range facilities involved maintained by the Civil Aeronautics Administration were functioning properly at the time. The weather conditions at Miles City, while adverse, were above the prescribed minimums and not beyond the capabilities of a pilot of Captain Shank's experience. The evidence shows that Captain Shank and other pilots of Northwest were accustomed to landing at Miles City under similar or even worse conditions. In fact, prior to the completion of the runway used, the Miles City Airport had only a single runway much narrower and shorter than the one in use at
