ASN logo
ASN Wikibase Occurrence # 145760
Last updated: 15 September 2021
This information is added by users of ASN. Neither ASN nor the Flight Safety Foundation are responsible for the completeness or correctness of this information. If you feel this information is incomplete or incorrect, you can submit corrected information.

Time:12:33 LT
Type:Silhouette image of generic H500 model; specific model in this crash may look slightly different
Hughes 369D
Owner/operator:Way to Go Heliservices Ltd.
Registration: ZK-HXZ
MSN: 117-0233D
Fatalities:Fatalities: 1 / Occupants: 1
Other fatalities:0
Aircraft damage: Written off (damaged beyond repair)
Location:Lake Sumner, North Canterbury -   New Zealand
Phase: Manoeuvring (airshow, firefighting, ag.ops.)
Departure airport:
Destination airport:
Investigating agency: CAA NZ
The helicopter crashed into an isolated lake in north Canterbury on Monday 21 May 2012.

The helicopter was one of two Rangiora-based Hughes 500s spraying gorse for the Department of Conservation. When one failed to return just before 3pm, the pilot of the other helicopter returned to the scene and spotted wreckage in the lake. The helicopter, with Rangiora pilot Michael Graeme Mehrtens aboard, is thought to be at the bottom of Lake Sumner (12m deep), about 140km northwest of Christchurch. The area is part of the Lake Sumner Conservation Park.

NZ CAA concluded CFIT occurred at some speed.

The investigation found that it was most likely that the pilot experienced some form of spatial disorientation with elements of somatogravic illusion and height perception illusion. This resulted in inadvertently flying a shallow descending flight path.


Accident investigation:
Investigating agency: CAA NZ
Status: Investigation completed
Duration: 1 year and 10 months
Download report: Final report


Rangiora 6Jan2011

Revision history:

21-May-2012 00:58 gerard57 Added
21-May-2012 04:11 Anon. Updated [Aircraft type, Source, Narrative]
22-May-2012 02:33 flyernzl Updated [Aircraft type, Registration, Cn, Operator]
23-May-2012 08:43 gerard57 Updated [Damage, Narrative]
16-Aug-2014 11:47 Aerossurance Updated [Time, Location, Source, Narrative]
17-Jul-2020 23:48 Ron Averes Updated [Aircraft type]

Corrections or additions? ... Edit this accident description