Casualties unknown

Cessna U206F forced landing near Nelspruit due to engine power loss (ZS-PWN)

ZA

On February 14, 2026, an aircraft (registration ZS-PWN) was involved in an aviation accident near ZA. Investigators recorded the probable cause as: Engine stoppage likely resulting from fuel starvation caused by fuel vapour formation (vapour lock), compounded by heavy spark plug fouling due to an overly rich mixture during restart attempts, which prevented the restoration of normal engine power. This summary draws on records from the South African Civil Aviation Authority (SACAA) Accident and Incident Investigations Division.

Sourcesthe South African Civil Aviation Authority (SACAA) Accident and Incident Investigations DivisionPrimary reportUpdated 2026-09-13Data APIEditorial standards

A Cessna U206F made a forced landing in an orchard near Mbombela after repeated engine stoppages attributed to fuel vapour lock and spark plug fouling during restart attempts.

What happened

On the morning of 14 February 2026, a Cessna U206F registered ZS-PWN departed Nelspruit Aerodrome (FANS) for Singita Sabie Sand Aerodrome (FASP) under visual meteorological conditions. The flight was a non-scheduled passenger operation conducted by a single pilot. Shortly after reaching cruise altitude, the engine stopped unexpectedly. The pilot attempted to restart the engine by manipulating the fuel selector and mixture controls, achieving only partial power. Unable to restore full thrust, the pilot decided to return to FANS.

During the approach back to Nelspruit, the engine failed twice more. After a third stoppage on final approach, with insufficient altitude to reach the runway, the pilot executed a forced landing in an abandoned litchi orchard located 0.84 nautical miles north of the aerodrome. The aircraft struck trees during the rollout, resulting in substantial damage. The pilot sustained minor injuries and was transported to a hospital for observation.

The investigation — what SACAA AIID examined and established

The Accident and Incident Investigations Division (AIID) reviewed maintenance records, fuel samples, and engine components. The aircraft had been maintained by the same organization since 2013, with the last inspection certified in October 2025. Bench tests of the engine components showed no mechanical failure capable of causing a stoppage. Fuel drained from the tanks was found to be of the correct grade and free of significant contamination, although some sediment was noted in the strainer. The investigation confirmed that the pilot had followed the prescribed emergency procedures for fuel vapour lock, as outlined in Cessna Service Information Letter SE79-25 and FAA Airworthiness Directive 79-15-01.

Findings

The primary cause of the accident was identified as fuel starvation caused by fuel vapour formation (vapour lock). While the pilot successfully restarted the engine twice, it could not deliver maximum power. A significant contributing factor was the condition of the spark plugs; all were found to be heavily fouled. This indicated that during the restart attempts, an overly rich mixture had been used, which impaired ignition and prevented normal combustion from being restored. The physical environment of the landing site, including trees and power lines, influenced the final flight path and increased the severity of the impact, though it did not initiate the accident sequence.

Safety action

SACAA AIID recommended that the pilot and operator implement regular recurrency training for the Cessna 206 series. This training should focus on maintaining critical skills for managing in-flight emergencies, specifically addressing scenarios involving engine power loss and restart procedures to prevent similar outcomes.

Probable cause

Engine stoppage likely resulting from fuel starvation caused by fuel vapour formation (vapour lock), compounded by heavy spark plug fouling due to an overly rich mixture during restart attempts, which prevented the restoration of normal engine power.