1936-DEC-27 · Rice Canyon, near Newhall, California

United Air Lines — Flight 34

United Air Lines Flight 34 crashed into the mountains near Newhall, California, during a night approach to Burbank, killing all 12 people on board. The aircraft struck a ridge in Rice Canyon at an elevation of 2,620 feet at approximately 7:38 p.m. while the pilot was attempting to navigate the Newhall Pass at an altitude lower than the surrounding terrain. Investigators determined the pilot failed to confirm local weather conditions via radio before attempting a visual transit of the pass under low cloud cover; however, this was significantly exacerbated by a technical radio failure or atmospheric interference that prevented the crew from receiving critical ground transmissions during the final 20 minutes of flight. The impact occurred while the aircraft was in a 28-degree right bank, suggesting the crew was attempting to turn away from the terrain at the moment of collision.

Aircraft

Boeing 247D

Registration

NC13355

Phase

Cause

Souls on Board

Fatalities

Origin → Dest

Mills Field Municipal Airport, San Francisco, California → Burbank Airport, Los Angeles, California

Report

Investigation Summary

Flight 34 was a multi-leg scheduled service from Oakland to Burbank with a stop in San Francisco. The flight from San Francisco was largely uneventful until it reached the Los Angeles basin. At 7:04 p.m., the pilot reported descending through broken clouds at 10,000 feet. Communication issues began shortly after; although the crew radioed Burbank at 7:09 p.m., a seventeen-minute silence followed during which ground controllers could not reach the aircraft. When contact was re-established at 7:29 p.m., the pilot appeared unable to hear the ground stations despite multiple facilities responding to his calls. At 7:36 p.m., the co-pilot requested the Burbank localizer beacon be activated. When ground control asked for their position, the co-pilot replied, 'just a minute.' Two minutes later, the aircraft struck the head of Rice Canyon. The wreckage was not located until the following morning. The investigation highlighted that the Newhall Pass was not navigable by instruments at low altitudes, forcing the pilot to rely on visual contact in poor weather conditions.

Final Conclusions

The Bureau of Air Commerce determined the probable cause was "an error on the part of the pilot for attempting to fly through Newhall pass at an altitude lower than the surrounding mountains without first determining by radio the existing weather." The investigation also noted significant radio interference or equipment failure that hindered two-way communication during the final 20 minutes of the flight.

Video Analysis

No video analysis linked for this case file yet.

Systems & Failure Modes

Localizer Beacon

A radio transmitter used to provide lateral guidance to pilots approaching a runway; the crew requested this be activated two minutes before impact.

Two-way Radio

The aircraft experienced a period of one-way communication where the crew could transmit but apparently not receive messages from Burbank, Fresno, or Bakersfield.

Interesting Facts

01All 12 occupants died instantly, primarily from blunt force trauma and skull fractures.
02The crash time was confirmed by multiple watches found on victims, all stopped at 7:38 p.m.
03The aircraft was in a 28-degree right bank at the moment of impact.
04Souvenir hunters reportedly looted the crash site before investigators could secure all instruments.
05The Boeing 247D was considered a modern, high-performance airliner for the mid-1930s.

Safety Actions & Advisories

Radio Equipment Testing

Source ↗

Following the investigation into the communication failure, the Bureau of Air Commerce and United Air Lines conducted extensive tests on the Boeing 247D's radio equipment to identify the cause of the one-way communication failure, focusing on potential static interference and receiver sensitivity.