What happened
On 5 January 2008, a Beech E55, registration ZS-PTB, was conducting a private flight from Kitty Hawk Aerodrome to Ubundu Game Lodge. The pilot, performing his first visit to this unlicensed aerodrome, conducted several overflights to inspect the runway for wildlife before committing to a landing on Runway 35.
During the short final approach, the aircraft encountered significant turbulence, including gusty westerly winds and a downdraught. In an attempt to manage the descent rate, the pilot applied back-pressure, causing the right wing to drop. This maneuver resulted in the propeller striking a three-conductor Eskom power line located approximately 60m from the runway threshold. The impact severed the lines, causing a local power failure, and rendered the aircraft nearly uncontrollable. The aircraft veered right, struck several small trees and shrubs, and came to rest 500m past the threshold. There were no fatalities and no injuries among the two occupants.
The investigation
SACAA AIID examined the wreckage and the site conditions at the private airstrip. The investigation confirmed that the aircraft's right-hand propeller had struck the 10kV power lines, with wire fragments found entangled around the No. 2 engine's crankshaft flange. The investigation also noted that the power lines were at a similar height to the trees near the runway threshold and lacked any visible hazard identification markers. The pilot's flight planning, based on a lodge brochure, contained no warnings regarding overhead obstructions.
Findings
- The primary cause of the accident was the collision with power lines during the final approach.
- The pilot was unfamiliar with the specific environment of the unlicensed aerodrome.
- Atmospheric conditions, specifically a downdraught and gusty crosswinds, contributed to the unstable approach.
- The power lines were difficult to detect until the aircraft was in very close proximity.
- The lack of hazard markers on the electrical conductors and the low, flat approach profile left no margin for error.