Accident Overview
On 7 February 2000 at 1430, a Beech 65-A90 King Air (registration ZS-IRJ) operating a military flight from Kimberley to AFB Waterkloof experienced a complete electrical failure during the flight. The pilot, holding a commercial license with 2628 total flying hours and 339 hours on the type, was carrying five passengers. The weather at the time was CAVOK.
Electrical Failure
While entering the Johannesburg Terminal Control Area (JHB TMA), radar control informed the pilot that the aircraft's transponder was intermittent. The pilot subsequently observed that both generators were offline, resulting in a total loss of electrical power. The cause of the failure was identified as a sheared starter-generator drive shaft on the right-hand engine and an undetermined failure of the generator on the left-hand engine.
Emergency Procedures and Landing
The pilot lowered the landing gear using the emergency extension system. However, during the landing on Runway 19 at AFB Waterkloof, the main undercarriage collapsed. There were no injuries among the six occupants.
Temporary Repairs and Ferry Flight
Temporary repairs were performed on the aircraft at AFB Waterkloof. The drive shaft on the right-hand starter-generator was replaced, and the aircraft was subsequently flown with the left-hand generator inoperative to an Approved Maintenance Organisation (AMO) at Lanseria for further repairs.
Investigation Findings
The South African Civil Aviation Authority investigated the accident. The probable cause was determined to be the complete electrical failure resulting from a failed starter-generator shaft on the right-hand engine and a defective left-hand generator.