50 fatalities

Flight 615 Collision with Terrain Near Oakland (N37550)

Union City, United States of AmericaLanding (descent or approach)

On August 24, 1951, a Douglas DC-6 (registration N37550) operated by United Airlines was involved in an aviation accident near Union City, United States of America during landing or approach. 50 people were killed. Investigators recorded the probable cause as: The failure of the captain to adhere to instrument procedures in the Newark area during an approach to the Oakland Municipal Airport, specifically by descending below minimum altitudes and failing to tune the radio range receiver. This summary draws on records from the Bureau of Aircraft Accidents Archives (B3A); 5 related events involving the same aircraft type or operator are linked below.

Sourcesthe Bureau of Aircraft Accidents Archives (B3A)Primary reportUpdated 2026-06-12Data APIEditorial standards

On August 24, Flight 615 crashed into Tolman Peak near Oakland, killing all 50 occupants. The accident resulted from the captain's failure to adhere to instrument procedures and minimum altitudes during a straight-in radio range approach.

Incident Overview

Flight 615 was operating under an instrument flight plan from Chicago to Oakland, followed by a Visual Flight Rules segment to San Francisco. On August 24 at 0354, the aircraft was cleared to descend to 6,000 feet MSL while approaching the Oakland area. Routine radio contacts were established with Air Route Traffic Control until 0416, when the flight reported over the Altamont Intersection and transferred control to Oakland Approach.

Final Approach Sequence

Approach Control cleared the aircraft to maintain at least 500 feet above cloud tops for a straight-in range approach from the Newark fan marker. At 0422, the crew requested an ILS approach but later retracted this request, advising they were approaching Newark. At 0425, the flight received clearance for a straight-in approach on the southeast course of the Oakland radio range. The final radio contact occurred at 0427 when the pilot reported leaving Newark inbound to Oakland.

Impact and Findings

One minute after the last transmission, the four-engine aircraft struck Tolman Peak, which stands at 985 feet high, located approximately 14.6 miles southeast of Oakland Airport. The impact destroyed the aircraft and killed all 50 occupants on board. Official findings indicated the captain failed to follow approved straight-in range approach procedures by descending below minimum altitudes for the Newark area. Additionally, neither radio receiver was tuned to the Oakland radio range station as required. The aircraft impacted terrain at 983 feet MSL with substantial engine power applied.

Probable cause

The failure of the captain to adhere to instrument procedures in the Newark area during an approach to the Oakland Municipal Airport, specifically by descending below minimum altitudes and failing to tune the radio range receiver.