Scandinavian Airlines System Flight 933 was a scheduled international flight from Denmark to the United States that on January 13, 1969, crashed into Santa Monica Bay at 19:21, approximately six nautical miles (11 km) west of Los Angeles International Airport (LAX) in California, United States.

The crash site was in international waters, but the National Transportation Safety Board carried out an investigation, which was published on July 1, 1970.

[7] Captain Kenneth Davies, a 50-year-old Briton, had been employed by SAS since 1948 and had a past in the RAF Coastal Command.

[9] The cabin crew consisted of Renning Lenshoj, Arne Roosand, Peter Olssen, Marie Britt Larsson, Susanne Gothberg-Ingeborg, and Ann-Charlotte Jennings.

[10] The flight departed Seattle at 15:46 Pacific Standard Time (PST), one hour and eleven minutes after schedule.

The aircraft made contact with Los Angeles Air Route Traffic Control Center at 17:32 and were told to hold at Bakersfield.

[11] At 18:39, the aircraft was cleared to descend via Fillmore and to keep an altitude of 1,500 meters (4,900 ft) via the newly designated Westlake Intersection, which was not yet on the charts.

While retaining use of the autopilot, the pilots reduced their speed to 160 knots (300 km/h; 180 mph) at the request of air traffic control at 19:07.

At 19:11, the aircraft received permission to bear 180 degrees and descend to and maintain 1,000 meters (3,300 ft) of altitude.

Meanwhile, the first officer believed that the flaps were fully extended and started reducing speed to 126 knots (233 km/h; 145 mph).

After the flight engineer confirmed that the nose gear was down and locked, the captain fully extended the flaps.

At this time, 19:20:42, the captain informed air traffic control that he was experiencing nose-gear problems that, if not resolved by the time the aircraft reached minimum altitude, would force him to cancel the landing and divert to the designated alternate, McCarran International Airport (now Harry Reid International Airport) in Las Vegas.

The flight engineer conducted a manual check of the landing gear from the cockpit peephole confirming it was down and locked.

He attempted to pull up through back pressure and adding power, but the aircraft hit the water before he was able to execute this maneuver.

The impact took place at 19:21:30 PST (03:21:30 on January 14 Coordinated Universal Time) in Santa Monica Bay, about 6 nautical miles (11 km; 6.9 mi) west of LAX, in international waters where the sea is 110 meters (360 ft) deep.

The crew did not recall any unusual sink rate, buffeting, or yawing, nor were there any instrument warnings except a last-moment flashing of the heading-difference light.

[17] The midsection was 13 meters (43 ft) long from the trailing edge of the wing to the rear pressure bulkhead.

The surviving three cabin crew, an off duty captain and flight attendant, evacuated the passengers onto the wings and into liferafts.

The Government of Norway requested that the investigation be carried out by the United States' National Transportation Safety Board.

[27] As the aircraft was found airworthy and able to be flown, the bulk of the work of the investigation commission focused on operational procedures.

[29] Another factor was that the SAS aircraft was forced to operate at the lowest-permissible safe speeds while closing in on the Cessna.

The first officer was distracted by the captain's dealings with the landing-gear issues, hindering him from primary task: flying the aircraft.

The cycling of the landing gear and delay in extending the flaps made speed and altitude control more difficult.

[31] Both the landing-gear issue and the concerns regarding speed made the captain focus on the possibility of a missed approach and the major inconvenience of diverting to Las Vegas.

[31] It was the commission's impression that the captain failed to properly monitor the approach, and crew resource management broke down.

The situation was worsened by the crew attempting to fly at 126 knots (233 km/h; 145 mph) when the aircraft was not configured for that speed.

[32] Most of the fatalities resulted from people having been trapped in the sinking sections which was caused by the collapsing of the structure after impact.

The collapse was caused by the compromise of the tubular integrity which was dependent on the keel beam that had been torn off on impact.

[34] The NTSB therefore advised the Federal Aviation Administration to articulate means to avoid similar compromised fail-safe designs in the future.

[34] The investigation commission produced the following conclusion: …the probable cause of this accident was the lack of crew coordination and the inadequate monitoring of the aircraft position in space during a critical phase of an instrument landing approach which resulted in an unplanned descent into the water.