Page:NTSB Aircraft Accident Report, United Airlines Flight 389.pdf/23

 test. During the testing of the upper rudder power units it was determined that the linear position transducer slide was not free to move resulting in an over-tolerance of the phase log test. No other discrepancies were noted. Testing of the elevator power control units showed no discrepancies except that the transducer output voltage was low and the autopilot override velocity timing was slow.

Testing of the ten flight spoiler actuators revealed that the Nos. 4 and 5 and Nos. 10 and 11 units did not pass a cold soak test. Further, the internal piston of the No. 10 actuator was broken and when power was applied the actuator went to the extended position.

The leading edge slat selector valve was recovered with the slide assembly in the retracted position and the No. 3 left hand slat actuating cylinder was found with the piston rod locked in the retract position.

The electrical stabilizer trim actuator was tested to stall torque specifications of 600-650 inch pounds in clockwise and counter clockwise directions. The unit stalled at 480 inch pounds clockwise and 456 inch pounds counter clockwise. Both the main stabilizer and autopilot cruise trim switches were found in the "on" position.

Two attitude indicators were recovered. One showed evidence of a 74-degree right bank and the other of 53-degree left bank. The second indicator showed a pitch attitude of approximately 5 degrees nose up. A master heading indicator was recovered and displayed a heading of 260 degrees on a test stand with a selected course of 251 degrees. Both automatic direction finding receivers were recovered. One was found set at approximately 390 kcs. and the other at approximately 780 kcs. The mode selector was in the loop position.