Underwater search for helicopter set to resume next week

Police expect to resume the search for a missing helicopter pilot at Lake Sumner, North Canterbury, next week.

The initial search was temporarily suspended on Monday, after a Navy submersible located debris from the aircraft, spread over a 50 square metre radius at a depth of 127 metres. The pilot was not located.

Canterbury Police Operations Manager, Inspector Craig McKay, says the search team is now planning for the next stage of the search and recovery, including a more detailed sonar survey.

"We are now looking at options that will help us get a fuller picture of what is on the lake bed, and allow us to retrieve the helicopter and the missing pilot, if that is possible," he says.

"As a first step we will bring the Police National Dive Squad back in with a Radial Sonar device. This will give us a more detailed scan of the debris field, and hopefully help to locate Mr Mehrtens.

"The dive squad will be ready to deploy as soon as we have sourced an extension to their cable to operate the radial sonar device at the depth of the wreckage. We are currently trying to source this as urgently as possible through international suppliers.

"We hope to be back in the lake early next week."

Inspector McKay says if the radial sonar is not able to locate the missing pilot, consideration will be given to bringing in specialist lake bed survey equipment to map the area.

If Mr Mehrtens is located, he says, the next stage in the recovery operation is to bring in a civilian remote-operated vehicle with a manipulator arm to retrieve the body.

Inspector McKay says Police have briefed Mr Mehrtens' family on plans for the next stage of the search and recovery operation.