Investigation and Probable Cause of Crash
The Civil Aeronautics Board investigated the accident. The investigation began immediately after locating the wreckage in the mountainous area southwest of San Francisco, about seven and a half miles southeast of the town of Half Moon Bay. The aircraft was almost entirely destroyed by impact and ensuing fire. It had initially topped several large redwood trees, shearing off one of its landing gear and leaving it hung-up in an oak, continued across a narrow ravine and crashed against the side of a steeply rising slope approximately half a mile beyond the first tree strike. The main wreckage area was at about 1,950 feet (590 m) above sea level.
The landing gear was down and locked at impact. There was no evidence of mechanical or structural failure prior to the impact.
The accident site was between the Half Moon Bay Fan Marker and the ILS Outer Marker and it appears that the flight did not maintain at least 500 feet (150 m) on top of clouds between these points but had descended in weather conditions which precluded reference to the ground.
In addition, the flight had reported being over the Half Moon Bay Fan Marker at 8:39 a.m. and then “Southeast, turning inbound” at about 8:42 a.m. In this time interval it would not have been possible for the flight at normal speed to have flown from the Half Moon Bay Outer Marker to the ILS Outer Marker, make the required turn and return to the site of the crash in accordance with Civil Aeronautics Authority approved instrument approach procedure. Thus it was likely that when the pilot reported he was “Southeast, turning inbound”, he was in fact southwest of the airport.
The investigation then stated that it was probable that the captain, after reporting that he was over Half Moon Bay, either saw the terrain momentarily through an unreported break in the overcast foggy conditions or because of a radio navigational error became convinced that his position was farther northeast and started to descend over what he believed was the proper area.
It was therefore concluded that the probable cause of the crash was the failure of the crew to follow prescribed procedures for an instrument approach.
Read more about this topic: BCPA Flight 304
Famous quotes containing the words investigation and, probable and/or crash:
“There is no one kind of thing that we ‘perceive’ but many different kinds, the number being reducible if at all by scientific investigation and not by philosophy: pens are in many ways though not in all ways unlike rainbows, which are in many ways though not in all ways unlike after-images, which in turn are in many ways but not in all ways unlike pictures on the cinema-screen—and so on.”
—J.L. (John Langshaw)
“I hope I may claim in the present work to have made it probable that the laws of arithmetic are analytic judgments and consequently a priori. Arithmetic thus becomes simply a development of logic, and every proposition of arithmetic a law of logic, albeit a derivative one. To apply arithmetic in the physical sciences is to bring logic to bear on observed facts; calculation becomes deduction.”
—Gottlob Frege (1848–1925)
“The tree the tempest with a crash of wood
Throws down in front of us is not to bar
Our passage to our journey’s end for good,
But just to ask us who we think we are....”
—Robert Frost (1874–1963)