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At this time the altimeter indicated that the aircraft was about 500 feet above the ground. The flare was useless because the aircraft was at too low an altitude to permit turning underneath it. The captain held his course and at an altitude of about 300 feet was able, by the use of the landing rights, to distinguish a grain field ahead. He headed for this field in a very steep glide and levelled off just before contact with the ground. The aircraft bounced once, settled on the wheels, which were still retracted, and rolled about 1000 feet across the grain field into on orchard where the wings and undercarriage were damaged by trees.
Subsequent inspection and tests of the engines and the fuel system revealed that each operated normally in every respect. Inspection of the fuel tanks immediately after the accident disclosed that the right main tank contained 197 gallons; the left main, 208 gallons; the right auxiliary and the left auxiliary tanks each contained a small amount fuel, estimated as between 5 and 8 gallons in each. The fuel gauges were checked and all except the gauge of the left auxiliary tank were found to be substantially accurate. The left auxiliary gauge, however, indicated 19 gallons. Further tests were conducted on this gauge and in each test the gauge indicated an amount of fuel appreciably in excess of the amount in the tank. Investigation revealed that the defect was in the tank unit. The entire mechanism had been recalibrated only a few hours before the subject flight. However, examination disclosed that the section of the tank unit was very erratic. On the basis of these tests, it is estimated that at the time of take-off from Fort Worth the left auxiliary tank contained approximately 15 gallons of fuel.
Statements by the captain and the first officer revealed that neither of them realized, when less of power was first apparent, that such power loss was due to lack of fuel in the left auxiliary tank. By failing to switch immediately to one of the full tanks, the gasoline lines and carburetor filled with air and an immediate free flow of fuel to the carburetor when the fuel selector valve was subsequently turned to the left main tank was thereby prevented. Due to lack of altitude, there was not time for the crew to clear the air from the fuel lines, thereby insuring a normal flow of fuel. The captain's technique in effecting the landing, which was accomplished with flaps up because lack or time prevented their use, was commendable.
The weather was excellent and did not contribute to the accident.
Investigation disclosed that the flight was dispatched and conducted in accordance with the Civil Air Regulations and with the carrier's procedure. Although the aircraft was in a critical position when the engines stopped, due to the fact that its cruising altitude was so low, it is believed that, on account or the large amount of air traffic between Fort Worth and Dallas, the present practice of air carriers in flying between those two points at an altitude of approximately 1500 feet above sea level should not be changed.
