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flight requested the Salt Lake City Air Route Traffic Control Center (ARTCC) not to vector them over Provo. A discussion about the new arrival procedure for Runway 34L pointed out that the Lehi intersection,[1] 13 miles northeast of Provo and 23 miles southeast of the Salt Lake City Municipal Airport,[2] was the initial fix for westbound arriving aircraft. At 1735:45 clearance was issued to descend at the pilot's discretion to 16,000 feet, and in his acknowledgement the captain requested, "... let me know when we're sixty miles east of Lehi." At 1738:05 the ARTCC controller notified the flight that they were 60 miles east of Lehi and they responded, "Okay we'll start her down." The flight proceeded in accordance with radar vectors, passing 5 miles south-southwest of Lehi where a radar handoff to Salt Lake City Approach Control was effected. New clearance altitudes were given during the continuous descent and at 1747:00 the approach controller advised, "United seventy two twenty seven... five miles south of Riverton Fan Marker coming on localizer course cleared for ILS runway three four left approach." At 1748:10, in response to the controller's request for the aircraft's altitude, the pilot replied "Okay we're slowed to two fifty (Knots) and we're at ten (10,000 feet) we have the runway in sight now, we'll cancel and standby with you for traffic." Control of the flight was transferred to the tower and at 1749:40 landing clearance was issued. At 1752:1 the tower controller reported on the interphone to the watch supervisor, "... United's on fire just landed." The accident occurred in darkness.
The crew stated that during the flight from Denver to Salt Lake City the first officer was flying the aircraft under the direction of the captain. During the descent they penetrated an overcast approximately 6,000 feet thick, with the engine anti-ice on. While in the clouds, at approximately 16,000 feet, idle thrust and speed brakes were selected. At 11,000 feet the speed brakes were retracted and shortly thereafter visual reference with the field was gained. The anti-ice switches were turned off and speed reduction continued to the reference speed[3] of 123 knots, as the landing gear and 40 degrees of flaps were selected. The flight continued descending at approximately 2,000 feet per minute (See Attachment A) with a full "fly-down" signal on the ILS indicator. The UAL recommended rate of descent during the landing approach is 6-800 feet per minute.
The flight crew testified regarding the sequence of events on the final approach as follows:
CAPTAIN - At approximately 6,500 feet m.s.l. he stopped the first officer from adding power. He estimated that 15-20 seconds later, at approximately 5,500 feet m.s.l., the first officer moved the thrust levers forward. When the engines did not respond, he moved the thrust levers to the takeoff power position, and assumed control of the aircraft. He estimated that this occurred about 1-1/4 miles from the runway at an altitude of 1,000 feet (5,226 feet m.s.l.), and at least 30 seconds prior to impact. Although he glanced at the engine instruments, he did not recall any readings.
- ↑ The intersection of 141-degree and 030-degree radials of the Salt Lake City and Provo VORTAC radio facilities, respectively.
- ↑ The airport is located at 40° 47' N latitude, 111° 58' W longitude. The published elevation is 4,226 feet.
- ↑ Reference speed is 1.3 times the stalling speed of the aircraft in the landing configuration.
