What happened
On 28 November 2013, a Beech F90 King Air, registration ZS-NFO, was conducting a private international flight from Beira Airport, Mozambique, to Lanseria International Airport, South Africa. While navigating under instrument flight rules, the pilot was directed by Radar Control through the Hartebeestpoetdam (HBV) and Lanseria (LIV) VOR stations.
To avoid an active thunderstorm, the pilot initially requested a heading of 240° and flew west for approximately 15 miles. However, after requesting a direct route to Lanseria, the aircraft entered a zone of heavy wind shear and hail. The pilot attempted an immediate turn to escape the weather, but the aircraft had already been struck by hail. Due to deteriorating conditions at the intended destination, the pilot requested a diversion to OR Tambo International Airport, where the aircraft landed safely.
The investigation
An investigation by the SACAA AIID examined the flight path, meteorological conditions, and the pilot's use of onboard equipment. The inquiry confirmed that the pilot held a valid Commercial Pilot Licence with appropriate instrument and night ratings, as well as a valid medical certificate. The aircraft was found to be well-maintained, with all systems functioning as designed, and the investigation ruled out mechanical failure as a contributing factor.
Meteorological data confirmed that the area around Lanseria was experiencing severe weather, including thunderstorms, heavy rain, and hail. The investigation also noted that the aircraft was equipped with weather radar, which the pilot had been utilizing during the flight.
Findings
- The aircraft sustained damage to its fuselage, wing, leading edges, spinners, exhaust, and tail lights.
- The pilot miscalculated the size of the thunderstorm, leading to a premature turn toward the storm cells.
- The pilot was unable to properly evaluate the weather scenario from a distance or establish an adequate escape route, resulting in the aircraft entering the hail.
- The pilot successfully managed the emergency by diverting to an alternative airport with better conditions.