What happened
On 27 April 2016, at approximately 1041Z, a mid-air collision occurred at Kitty Hawk aerodrome during the final approach for Runway 01. The incident involved a Robinson R44 helicopter, registration ZS-RXD, and an Aeroprakt A-22LS Foxbat, registration ZU-KOL.
The helicopter pilot had flown from the North West Province, routing via Air Force Base Waterklo and broadcasting intentions on frequency 120.65. After an overhead pass at approximately 500ft AGL, the pilot executed a tight, descending right-hand turn. Simultaneously, the ZU-KOL aircraft was on its final approach at a similar altitude. During the maneuver, the main rotor of the ZS-RXD struck the right wing and propeller of the ZU-KOL.
Following the impact, the pilot of the ZU-KOL experienced severe engine vibrations and opted to perform a forced landing on nearby rocky terrain. While the touchdown was initially smooth, the aircraft's nose landing gear collapsed upon hitting rocks, causing substantial damage to the engine, propeller, and nose section. The ZS-RXD also sustained damage to its main rotor blades. No injuries were reported for either pilot.
The investigation
SACAA AIID examined the flight histories, maintenance records, and radio communications of both aircraft. The investigation established that both pilots held valid licenses and medical certificates, and both aircraft were airworthy and properly maintained. Meteorological conditions were favorable, with good visibility and light winds, meaning weather was not a contributing factor.
Investigators reviewed radio transmissions from the period. While the ZU-KOL pilot had reported his position on the circuit, the helicopter pilot had received a warning from a third aircraft (a Dornier) that two aircraft were active in the circuit. However, the helicopter pilot did not further verify the exact positions or altitudes of the other traffic before initiating his descent.
Findings
- The collision was primarily caused by the ZS-RXD pilot performing a steep descending right-hand turn that placed the helicopter on a direct collision course with the fixed-wing aircraft.
- The helicopter pilot failed to follow established unmanned aerodrome procedures, specifically failing to confirm the exact position and altitude of other traffic after being alerted to their presence.
- The ZU-KOL sustained additional damage during its forced landing due to the uneven, rocky nature of the landing site and the failure to apply brakes during the ground roll.