History of Flight
On 30 October 2021 at 0600Z, a Cessna 182P (registration ZS-PMT) departed from Lanseria International Airport (FALA) for Rand Airport (FAGM) with a pilot and one passenger on board. The flight was conducted under visual flight rules (VFR) by day in accordance with Part 91 of the South African Civil Aviation Regulations. After departure, the pilot intended to land at Blue Valley Mountain private airstrip in Hekpoort, Krugersdorp, but aborted the landing due to wet grass and executed a missed approach. The aircraft then proceeded toward FAGM while maintaining an altitude between 6,500 and 7,000 feet. While still some distance from the Romeo Delta entry point to FAGM airspace, the pilot noticed the engine became sluggish, followed by a drop in manifold air pressure (MAP) and a loss of engine power. The pilot contacted FAGM air traffic control (ATC), reported the situation and position, and was cleared for a long straight-in approach to Runway 11. As the aircraft continued losing speed and altitude, the pilot determined that reaching the runway was not possible and initiated a forced landing on an open field approximately 1.2 nautical miles west of FAGM. During the forced landing, the aircraft struck tree branches before coming to rest near a riverbank. A post-impact fire ensued. Both occupants sustained injuries, including first- and third-degree burns. The aircraft was destroyed.
Engine Examination
Post-accident visual inspection of the engine revealed that a castellated nut and bolt connecting the carburettor throttle control lever to the throttle were missing. This led to separation of the throttle control lever from the throttle, causing unregistered inputs from the cockpit.
Probable Cause and Contributory Factors
The investigation determined that the throttle cable separated from the throttle lever control in flight due to a missing cotter pin on the castellated nut. This caused the engine to run at idle. Consequently, the pilot was unable to maintain altitude, resulting in an unsuccessful forced landing followed by a post-impact fire that destroyed the aircraft. Contributory factors included an inadequate pre-flight inspection and failure to identify the missing cotter pin during maintenance.