Page:NTSB Aircraft Accident Report, United Airlines Flight 389.pdf/32

 Examination of the fragments of the No. 3 engine that were recovered indicates that the engine was rotating at the time of impact. While there is a possibility of an inflight catastrophic problem with this engine, there is no evidence such as fire damage or shrapnel damage to the recovered portions of the engine cowling to support this possibility. Catastrophic engine failures ordinarily make themselves known through fire damage and puncture damage to the surrounding structure and the engine cowling. Also, the crew was conducting a radio conversation with approach control until just before the accident and gave no indication that any problem existed with the aircraft or any of its systems.

Examination of the fuel boost pumps revealed no evidence of fire, overheating or other operational distress. The fuel valves were found in the positions prescribed by the carrier for normal flight operation. One piece of the recovered fuel system evidenced some soot or smoke damage but the rest of the system was free of any evidence of fire. This sooting was probably the result of the explosion that occurred on impact.

The thrust reversers were found to have been in the forward thrust, normal flight position, at impact. While the No. 1 thrust reverser doors were slightly out of the forward thrust position when recovered, this was Judged to have been the result of impact damage.

There is no evidence on which we can base a finding of engine failure before impact. All three engines were operating when the aircraft struck the water. Based on the relative damage to the compressor blades of the Nos. 2 and 3 engines they were operating at a higher rotational velocity than No. 1. This further supports the theory that the aircraft was right-wing-down at initial