Page:CAB Aircraft Accident Report, Allegheny Airlines Flight 371.pdf/6

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Weather

The area forecast issued by the U. S. Weather Bureau Forecast Center at Idlewild Airport, New York, for the 12-hour period beginning at 0800 e. s. t., for the route between Harrisburg and Selinsgrove, indicated ceilings of 3,000 to 4,000 feet with tops at 8,000 feet and a higher broken to overcast cloud deck at 10,000 feet with tops at about 14,000 feet. Conditions were forecast to be locally variable to 1,000-foot ceiling and visibility five miles in snow showers and a possibility of freezing rain until 1200 e. s. t.

The Williamsport terminal forecast was also prepared by the Weather Bureau Forecast Center at Idlewild. This forecast was valid from 0600 to 1800 and indicated that until 1100 conditions would be 4,000 overcast, wind west southwest 15 miles per hour; occasional light snow showers, chance of moderate freezing rain.

A flash advisory was issued effective at 0820, valid until 1120, and called for ceilings below 1,000 feet and visibility occasionally two miles or less in snow showers for an area which included Williamsport.

This 0820 flash advisory was not furnished to the crew of Flight 371, however, the crew was given the current weather at Williamsport at 0923 and again at 0935 from the Williamsport radio communicator. The 0934 Williamsport weather which Flight 371 received at 0935 was as follows: 1,000 feet scattered, precipitation obscuration 2,000 feet, visibility 1-1/2 miles in light snow, wind west at four knots, altimeter setting 30.26 inches.

Witnesses

A number of persons responded to the Board's request for witnesses to this accident. Of the persons contacted only a few were able to give information which could be correlated with the aircraft involved in this accident. One witness was a meteorologist employed by the U. S. Weather Bureau who was on duty at the Williamsport Airport at the time of the accident. This witness observed the aircraft first approach the field too high to land, then turn to the right approximately over the Administration Building to enter a landing pattern for runway 27. The aircraft was visible to this witness throughout its landing pattern except for approximately four seconds while on the base leg due to intermittent obscuration by fracto-cumulus clouds. This witness observed the aircraft to continue on its approach to a position which he estimated to be approximately one-fourth of a mile from the end of runway 27, at an altitude of approximately 400 feet above the ground, and on a heading of approximately 270 degrees. The witness stated that at this point the aircraft was turned to its left and then disappeared into clouds and snow showers in a southerly direction toward Bald Eagle Mountain. He stated that a short while later he heard an increase in power of the aircraft's engines, followed almost immediately by the sound of the aircraft crashing into the mountain.

Several deer hunters were in the immediate area of the crash. They indicated that at the time of the crash the visibility was so restricted by the snow that they were unable to continue their hunting.

Another witness was the captain of a Capital Airlines DC-3. This captain stated that at the time of his observation he was parked near the intersection of the taxiway and runway 27, approximately 150 feet back, awaiting clearance for his takeoff which was contingent upon the landing of the aircraft then making its approach (Flight 371).