Pan Am Flight 812 (PA812), operated by a Pan Am Boeing 707-321B registered N446PA and named Clipper Climax, was a scheduled international flight from Hong Kong to Los Angeles, California, with intermediate stops at Denpasar, Sydney, Nadi, and Honolulu.

[1] On April 22, 1974, it crashed into rough mountainous terrain while preparing for a runway 09 approach to Denpasar after a 4-hour 20-minute flight from Hong Kong.

Sydney resident Bruce Marich missed the flight but his two fellow directors were killed.

The location of the accident was about 42.5 nautical miles (48.9 mi; 78.7 km) northwest of Ngurah Rai International Airport.

However, according to the transcription of Air Traffic Control voice recorder this message was never received by the Bali Tower.

It was subsequently found that the aircraft had hit a mountain approximately 37 miles (60 km) northwest of the Bali airport.

The last contact was established by Flight 812 at Mesehe Mountain, a dormant volcano located near the airport.

[4] Evacuation of the bodies was hampered due to the terrain of the crash site, which was located in a mountainous area.

[5] It had logged about 28000 total airframe hours and 9150 takeoff and landing cycles and was equipped with four Pratt & Whitney JT3D-3B engines.

Others stated that Captain Zinke was trying to land from the northwest, where the mountains were located, rather than the usual route (from the east).

The CVR was recovered in good condition, while the FDR had some damage on its outer case due to the crash.

[13] Captain Zinke didn't encounter any difficulties on the approach procedure to Denpasar's Ngurah Rai Airport.

Investigators stated that the right hand turn was made at a position approximately 30 NM North of the beacon.

[13] Several attempts were made to regain proper indication on the ADFs after the turn, however this couldn't happen since the plane was "shielded" by the mountain.

[13] It was determined that the premature execution of a right-hand turn to join the 263-degree outbound track, which was based on the indication given by only one of the radio direction finders while the other one was still in steady condition, is the most probable cause of the accident.

Following the crash, Pan Am addressed the issue and encouraged an early form of Crew Resource Management.

Due to the crash of Flight 812, the Federal Aviation Administration ordered an in-depth inspection of the airline's worldwide flight operations including pilot training, area qualification, operational procedures, pilot supervision and scheduling, line-check procedures, and other related matters of safety.

[14] On 8 May 1974, Pan American Airways ordered the installation of a new cockpit warning device designed to prevent crashes such as this April 22 incident.

The ground proximity warning system provided additional indications, for example if a plane was heading for a mountain slope or if it was too low for a landing.

In the aftermath of the crash, Pan Am stopped their Hong Kong to Sydney flights via Bali.