ASN Wikibase Occurrence # 272562
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| Date: | Friday 1 July 2011 |
| Time: | |
| Type: |  Eurocopter AS 350B3 |
| Owner/operator: | |
| Registration: | ZS-HDK |
| MSN: | 7027 |
| Year of manufacture: | 2010 |
| Fatalities: | Fatalities: / Occupants: |
| Aircraft damage: | |
| Category: | Accident |
| Location: | To the left of Runway 35 at Sishen Aerodrome -
 South Africa
|
| Phase: | |
| Nature: | |
| Departure airport: | Sishen Aerodrome (FASS), (Northern Cape province) |
| Sishen Aerodrome (FASS), (Northern Cape province) | |
| Investigating agency: | CAA S.A. |
| Confidence Rating: |  Accident investigation report completed and information captured |
On 1 July 2011, a Eurocopter AS350B3 helicopter, registration ZS-HDK, was being utilized in a geographical survey flight in the Sishen area. Onboard the helicopter was two pilots and a survey equipment systems operator. On approach to the Sishen aerodrome at a height of approximately 1200 feet above ground level (AGL), the pilot-not-flying (PNF), without permission from the pilot-in-command (PIC), who was also the pilot flying (PF) at the time, deactivated the 'ACCU TST'? switch (Accumulator Test Switch) on the instrument panel and the 'HYDR'? (Hydraulic) warning light illuminated. The PNF then suggested they perform a simulated' hydraulic failure as a training exercise whereby the PF agreed. They followed the pilot's operating handbook (POH) procedure to instigate the simulated failure, which required the master hydraulic switch located on the collective pitch lever to be switched off. The PF then reduced the speed as required and lined the helicopter up for runway 35 whilst descending towards the landing area. At about 3-6 feet above the ground the PNF asked the PF to switch on the hydraulic switch on the collective pitch lever, whereby the PF complied. The helicopter suddenly started to yaw to left. The PF was unable to counter act the yaw with the rudder pedals, which was described by him as being very hard at that stage. The PNF then took control of the helicopter but was also unable to address the yaw rate, which by now had intensified. During the yaw, the right-hand skid gear struck the ground and a dynamic rollover ensued with the helicopter coming to rest on its right-hand side. Neither of the occupants onboard was injured during the sequence of the accident. The helicopter sustained substantial damage during the sequence of the accident. Probable Cause Unsuccessful landing, following interference by the pilot-not-flying during a critical phase of flight, resulting in a loss of control in close proximity to the ground, which was aggravated by the incorrect reactivation of the hydraulic system.
Accident investigation:
 |
|
Sources:
S.A. CAA
History of this aircraft
Other occurrences involving this aircraft
| 15 October 2015 | 5Y-DKK | General Aviation - Tz | 4 | Selous Game Park |  |
w/o |
Revision history:
| Date/time | Contributor | Updates |
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