Investigation Summary
The accident was precipitated by a failure in the aircraft's No. 1 electrical system, which led the crew to request a holding pattern to consult with United Airlines maintenance. The approach controller issued a holding clearance that was later deemed 'incomplete and ambiguous' by investigators, as it did not specify a holding fix or direction, and the crew accepted it without clarification. Crucially, the crew requested to leave the approach frequency for a 'little minute' but remained absent for seven and a half minutes. During this period, the aircraft entered a valley surrounded by high terrain. The controller, realizing the aircraft was in danger, was unable to transmit warnings until the crew returned to the frequency. By the time the crew responded to the controller's urgent instructions to turn left and climb, the aircraft was too low to clear the ridge. The investigation also revealed that the cockpit voice recorder (CVR) was inoperative, which hindered the NTSB's ability to analyze the crew's internal coordination and decision-making process.
Final Conclusions
The NTSB determined the probable cause was the controller's issuance and the flight crew's acceptance of an incomplete and ambiguous holding clearance, combined with the crew's failure to adhere to established procedures for communication impairment and holding. The board noted that both the controller and crew had developed habits of imprecise communication due to long-term exposure to radar environments. The failure of the No. 1 electrical system was cited as a contributing factor.
Photographic Evidence (1)
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Crew Experience
Captain
John Fender, age 49
First Officer
Phillip Modesitt, age 46
Systems & Failure Modes
No. 1 Electrical System
The failure of this system for unknown reasons initiated the emergency and led to the crew's distraction while troubleshooting landing gear lights.
Cockpit Voice Recorder (CVR)
The device was inoperative, preventing investigators from hearing the crew's internal discussions during the troubleshooting and holding phases.
Interesting Facts
- 01The aircraft impacted a ridge on Ed's Peak in the Wasatch Range at the 7,200-foot level.
- 02The aircraft was completely destroyed, with no debris larger than a briefcase reported by rescuers.
- 03The cockpit voice recorder (CVR) was found to be inoperative at the time of the crash.
- 04The flight was a cargo operation with no passengers on board.
- 05Weather at the time included rain, reported as heavy by some witnesses.
- 06The crash site was in the Wasatch Range near Kaysville and Fruit Heights, Utah.
Safety Actions & Advisories
Communication and Holding Procedures
Source ↗The NTSB investigation highlighted the dangers of 'incomplete and ambiguous' clearances and the necessity for crews to adhere strictly to communication impairment procedures. The case is frequently cited in CRM training regarding the risks of leaving an ATC frequency during an emergency without maintaining situational awareness of terrain.