Page:NTSB Aircraft Accident Report, United Airlines Flight 389.pdf/29

 2.

2.1

A review of the available evidence has eliminated all causal areas other than those involving the operation of the aircraft. No evidence was found that would indicate other than normal operation of the powerplants and systems at the time of impact. There is no evidence that will support a finding of sabotage, flight crew incapacitation, or any malfunction of the aircraft.

There is no indication that the weather played any part in this accident. The weather observed and reported by the U. S. Weather Bureau and the crew of the B-707 aircraft that was operating behind UAL 389 revealed that the weather was suitable for this type of operation. The only possible problem the weather may have presented was limited visibility, but there is no evidence to indicate that after descending through the clouds, the flight was required to operate in less than VFR weather conditions. Light airframe icing could have occurred in the descent down to about 13,000 feet however, this should have had no effect on the safe operation of the flight. The thunderstorm activity in the area was all to the north of the aircraft's flightpath and there is no indication of other than light turbulence during the latter part of the flight.

The damage to the structure indicated the aircraft struck the water slightly nose up, with a slight right-wing-down attitude. The breakup of the fuselage and wings was extensive with the area below the cabin floor fragmented, and little of this area was recovered. The wreckage pattern indicates the aircraft struck the water on a heading of approximately 256