What happened
On 26 November 2021, a Cessna 421B Golden Eagle, registration ZS-IGG, departed Hoedspruit Eastgate Aerodrome for Rand Aerodrome. The flight, operated under private provisions, was cruising at 14,000 feet when the pilot reported that the engines were running rough while over Witbank. At the time, the aircraft was flying in instrument meteorological conditions with freezing temperatures and light drizzle.
Following the engine instability, the pilot requested a descent and was directed toward Middleburg Aerodrome. In an attempt to rectify the issue, the pilot activated the auxiliary fuel pumps, suspecting fuel starvation. However, during the final approach to Runway 14, both engines ceased operation simultaneously. Because the propellers were not feathered, the pilot was unable to reach the runway and instead performed a forced landing in an open field approximately 0.81 nautical miles north of Middleburg. The aircraft sustained substantial damage, and while the pilot sustained minor injuries, the two passengers were unharmed.
The investigation
SACAA AIID investigators examined the aircraft's maintenance records, which showed the Cessna 421B Golden Eagle had been properly maintained and was airworthy. The investigation focused on the environmental conditions and the pilot's actions during the emergency. Investigators noted that the pilot was operating as a single crew member in a high-workload environment.
Findings
- The primary cause of the double-engine failure was likely ice obstructing the engine air filters, a phenomenon where moisture-laden air freezes on the induction system components.
- The pilot misidentified the source of the engine malfunction, incorrectly attempting to address a perceived fuel issue by switching fuel pumps to high mode rather than utilizing the aircraft's alternate air source.
- The pilot experienced task saturation due to the high workload of managing an engine emergency alone while flying in instrument meteorological conditions in an unfamiliar area.
- Neither propeller was feathered during the final approach phase.