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Last updated: 26 April 2017
Datum:zaterdag 18 januari 1969
Type:Silhouette image of generic B721 model; specific model in this crash may look slightly different
Boeing 727-22C
Luchtvaartmaatschappij:United Air Lines
Registratie: N7434U
Constructienummer: 19891/631
Bouwjaar: 1968-09-04 (5 months)
Aantal vlieguren:1036
Motoren: 3 Pratt & Whitney JT8D-7
Bemanning:slachtoffers: 6 / inzittenden: 6
Passagiers:slachtoffers: 32 / inzittenden: 32
Totaal:slachtoffers: 38 / inzittenden: 38
Schade: Afgeschreven
Gevolgen: Written off (damaged beyond repair)
Plaats:20 km (12.5 mijl) W van Los Angeles, CA (   Verenigde Staten)
Fase: Kruisvlucht (ENR)
Soort vlucht:Binnenlandse lijnvlucht
Vliegveld van vertrek:Los Angeles International Airport, CA (LAX/KLAX), Verenigde Staten
Vliegveld van aankomst:Denver-Stapleton International Airport, CO (DEN/KDEN), Verenigde Staten
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:

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."


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 March 1970
duration of investigation: 1 year and 2 months
download report: United Air Lines, Inc., Boeing 727-22C, N7434U, near Los Angeles, California, January 18, 1969. (NTSB/AAR-70-06)


FAA issued 4 Airworthiness Directives
NTSB issued 2 Safety Recommendations

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Deze kaart geeft het vliegveld van vetrek weer en de geplande bestemming van de vlucht. De lijn tussen de vliegvelden geeft niet de exacte vliegroute weer.
De afstand tussen Los Angeles International Airport, CA en Denver-Stapleton International Airport, CO bedraagt 1356 km (848 miles).

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Boeing 727

  • 10e ongeval
  • 9e dodelijk ongeval
  • 1832 built
  • 6e zwaarste ongeval (toen het plaatsvond)
  • 39e zwaarste ongeval (op dit moment)
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 Verenigde Staten
  • 54e zwaarste ongeval (toen het plaatsvond)
  • 89e zwaarste ongeval (op dit moment)
» safety profile