Accident description
Last updated: 28 November 2014
Status:Final
Date:Saturday 18 January 1969
Time:18:21
Type:Boeing 727-22C
Operator:United Air Lines
Registration: N7434U
C/n / msn: 19891/631
First flight: 1968-09-04 (5 months)
Total airframe hrs:1036
Engines: 3 Pratt & Whitney JT8D-7
Crew:Fatalities: 6 / Occupants: 6
Passengers:Fatalities: 32 / Occupants: 32
Total:Fatalities: 38 / Occupants: 38
Airplane damage: Damaged beyond repair
Location:20 km (12.5 mls) W off Los Angeles, CA (   United States of America) show on map
Phase: En route (ENR)
Nature:Domestic Scheduled Passenger
Departure airport:Los Angeles International Airport, CA (LAX/KLAX), United States of America
Destination airport:Denver-Stapleton International Airport, CO (DEN/KDEN), United States of America
Flightnumber: 266
Narrative:
Boeing 727-22C N7434U operated Flight 266 from Los Angeles to Denver, CO and Milwaukee, WI. The aircraft had been operating since January 15, 1969, with the No. 3 generator inoperative. This was allowed because according to the Minimum Equipment List, the aircraft is airworthy with only two generators operable provided certain procedures are followed and electrical loads are monitored during flight.
Flight 266 was scheduled to depart the gate at 17:55, but was delayed until 18:07 because of the inclement weather and loading problems. The flight commenced its takeoff roll on runway 24 at approximately 18:17. At 18:18:30 the sound of an engine fire warning bell was heard in the cockpit. The crew reported a no. 1 engine fire warning and stated that they wanted to return to the airport. Shortly after shutdown of the No. 1 engine, electrical power from the remaining generator (No. 2) was lost. Following loss of all generator power, the standby electrical system either was not activated or failed to function. Electrical power at a voltage level of approximately 50 volts was restored approximately a minute and a half after loss of
the No. 2 generator. The duration of this power restoration was just 9 to 15 seconds. The Boeing descended and struck the sea 11.3 miles west of the airport. The ocean depth at this point is approximately 950 feet.


PROBABLE CAUSE: "The loss of attitude orientation during a night, instrument departure in which all attitude instruments were disabled by loss of electrical power. The Board has been unable to determine (a) why all generator power was lost or (b) why the standby electrical power system either was not activated or failed to function."

Sources:

Official accident investigation report
investigating agency: National Transport Safety Bureau (NTSB) - United States of America
report status: Final
report number: NTSB/AAR-70-06
report released:18-MAR-1970
duration of investigation:424 days (1 year 2 months)
download report: United Air Lines, Inc., Boeing 727-22C, N7434U, near Los Angeles, California, January 18, 1969. (NTSB/AAR-70-06)
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Follow-up / safety actions

FAA issued 4 Airworthiness Directives
NTSB issued 2 Safety Recommendations

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Map
This map shows the airport of departure and the intended destination of the flight. The line between the airports does not display the exact flight path.
Distance from Los Angeles International Airport, CA to Denver-Stapleton International Airport, CO as the crow flies is 1356 km (848 miles).

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Boeing 727

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