On September 22, 1984, a Ryan-navion NAV-4-1908 (registration N4908K) was involved in an aviation accident near Milpitas, CA. Investigators recorded the probable cause as: The manufacturer's investigation found no mechanical discrepancies to explain the engine stoppage, leaving the cause undetermined. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
An aircraft experienced an immediate engine failure at approximately 220 feet above ground level during the initial climb phase, resulting in a forced landing within a garbage dump site.
What happened
The aircraft departed from the airport and began its initial climb. Shortly after becoming airborne, the engine ceased producing power while the aircraft was at an altitude of approximately 220 feet above ground level. With no remaining altitude to recover, the pilot initiated a forced landing procedure. The aircraft descended rapidly and impacted the ground in a nearby garbage dump.
The investigation
Following the accident, investigators conducted a thorough examination of the aircraft to determine the mechanical cause of the engine stoppage. The post-accident inspection revealed no discrepancies or mechanical failures that could account for the sudden loss of power. All systems appeared normal upon physical inspection.
Findings
The weather conditions at the time of the accident were clear, with an ambient temperature of 73 degrees Fahrenheit and a dew point of 50 degrees Fahrenheit. These conditions did not suggest any immediate meteorological hazards such as icing or severe turbulence. The primary factor in the event was the unexplained loss of engine power during the critical takeoff phase.
Probable cause
The manufacturer's investigation found no mechanical discrepancies to explain the engine stoppage, leaving the cause undetermined.