Accident description
Last updated: 23 May 2013
| Status: | Final |
| Date: | 12 SEP 1951 |
| Time: | 10:46 |
| Type: | Boeing 377 Stratocruiser 10-34 |
| Operator: | United Air Lines |
| Registration: | N31230 |
| C/n / msn: | 15970 |
| First flight: | 1949 |
| Total airframe hrs: | 1971 |
| Engines: | 4 Pratt & Whitney R-4360 |
| Crew: | Fatalities: 3 / Occupants: 3 |
| Passengers: | Fatalities: 0 / Occupants: 0 |
| Total: | Fatalities: 3 / Occupants: 3 |
| Airplane damage: | Written off |
| Airplane fate: | Written off (damaged beyond repair) |
| Location: | off Redwood City, CA (United States of America)
 |
| Phase: | Approach (APR) |
| Nature: | Training |
| Departure airport: | San Francisco International Airport, CA (SFO/KSFO), United States of America |
| San Francisco International Airport, CA (SFO/KSFO), United States of America | |
| Flightnumber: | 7030 |
United Air Lines' Boeing Stratocruiser "Mainliner Oahu" was being used for a semi-annual instrument check of a captain. In addition, consideration had been given to investigating the feasibility of using the Oakland, California, Municipal Airport for certain phases of crew training in this type aircraft for a new class of pilots and flight engineers which was to convene that afternoon. The flight departed at 09:42 and reported on top of the broken scattered clouds four minutes later. The flight proceeded to Oakland, where a simulated ILS approach was carried out, followed by a missed approach procedure. The flight again reported on top at 10:36. Another simulated ILS approach was requested of the Oakland tower but the flight was advised that there would be a delay due to other traffic. In view of this, the pilot decided to return to San Francisco. At 10:39, the flight was cleared for an ILS approach to the San Francisco Airport. The aircraft, with No. 4 propeller feathered, stalled and abruptly dived from an altitude of approximately 300 feet and was demolished upon impact in San Francisco Bay.
PROBABLE CAUSE: "An inadvertent stall at a low altitude from which recovery was not effected." Events:
Sources:
» CAB File No. 1-0089
Photos
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 San Francisco International Airport, CA to San Francisco International Airport, CA as the crow flies is NAN km (NAN miles).
Distance from San Francisco International Airport, CA to San Francisco International Airport, CA as the crow flies is NAN km (NAN miles).
