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Atlas / NTSB / WPR20FA077

NTSB CAROL · Event

Event WPR20FA077

2020-01-24 Auburn, California, United States Fatal 1 aircraft Status: Completed

Aircraft involved

Probable cause & findings

A total loss of engine power due to a combination of mechanical engine anomalies. Contributing to the accident was inadequate maintenance that failed to identify the engine anomalies.

Factual narrative

The pilot departed on a local flight with two passengers. Several witnesses reported that they heard the airplane’s engine backfiring and sputtering and subsequently heard the engine quit. The surviving passenger, who was seated in the front right seat, stated that the engine lost power and there was nowhere to land. The airplane subsequently impacted heavily wooded terrain about 1 mile from the departure airport. Postaccident examination of the engine revealed that the No. 7 cylinder intake valve was stuck open. The No. 2 cylinder front spark plug was defective, and the Nos. 2- and 4-cylinders’ ignition wires were frayed, worn, and displayed arcing, which likely led to erratic operation or a lack of ignition in these two cylinders. The culmination of these issues most likely led to the engine running rough, backfiring, and subsequently losing total power. An annual inspection was accomplished on the airframe and engine about 2 months before the accident. General maintenance practices and the inspection should have identified the anomalies that were found during the postaccident engine examination. Source: NTSB Aviation Accident Database Retrieved: 2026-02-12

NTSB Findings

Hierarchical cause / factor breakdown from the FAA bulk avdata database. Each finding tagged C (Cause) or F (Factor).

  • Aircraft-Aircraft power plant-Engine (reciprocating)-Recip eng cyl section-Failure
  • Aircraft-Aircraft power plant-Engine (reciprocating)-Recip eng wiring-Damaged/degraded
  • Aircraft-Aircraft power plant-Ignition system-Spark plugs/igniters-Damaged/degraded
  • Environmental issues-Physical environment-Terrain-Mountainous/hilly terrain-Contributed to outcome
  • Personnel issues-Task performance-Maintenance-Scheduled/routine maintenance-Maintenance personnel

Verbatim from NTSB's published report. Source file NTSB_2020_WPR20FA077.txt. Findings + structured fields enriched from FAA avall.mdb. Full investigation docket on data.ntsb.gov ↗.

Related research

What the literature says.

Academic papers and agency reports matching this event's aircraft type or causal vocabulary (maintenance). Sourced from NASA NTRS, NTSB Safety Studies, FAA CAMI, AOPA Air Safety Institute, Embry-Riddle Scholarly Commons, arXiv, and the Semantic Scholar academic graph.

Browse the full corpus — academia portal ↗