A New Zealand-developed aerial drone was used for the first time in the search for a Christchurch man.
Developed by Canterbury Coastguard air patrol volunteers, the experimental unmanned aerial vehicle carrying two cameras was used by police scouring tussock and bush for Peter Crowther in Arthurs Pass National Park last week.
Canterbury police search and rescue co-ordinator Sergeant Ryan O'Rourke said the drone showed great potential despite failing to find Mr Crowther, who has been missing since June 14.
Mr O'Rourke said the drone was used over a wide area near the Mt White Bridge where Mr Crowther's car was found on Sunday, July 7, saving search volunteers time and effort.
"It was mostly used over open tussocky areas that needed to be searched, covering quite a big area of land - about 3km by 1km," he said.
"It was interesting to see it demonstrated," he said.
"It definitely has potential in the long term, but probably more in coastal searches.
Its limitation was that it can't see through bush."
Coastguard Canterbury air patrol vice-president and project co-ordinator Gordon McKay said the aircraft had its first "very successful" field test last Wednesday.
"We've done some basic testing, but it was the first time it has been used in a field situation," he said.
"The lessons we learned will be very valuable in developing the technology."
Mr McKay said the aircraft located several possible targets that appeared out of place in the tussocks, allowing searchers to send in ground parties for a closer look.
One of the objects captured by the on-board camera turned out to be a camouflaged hunting hide.
"Unfortunately there was nothing that was useful to the searchers," he said.
Mr McKay said Coastguard Canterbury was developing the drone to assist in rescue work.
The idea came from a brainstorming session by air patrol volunteers when the use of model aircraft was mentioned.
Ten members of the 25-strong air patrol group were involved in producing the prototype.
"Rather than just having a laugh we decided to look at developing the idea," he said.
The drone, a "flying wing", was piloted from the ground by a volunteer using a radio transmitter-like a model aircraft and capable of sending live camera footage to a control room allowing searchers to gain "a much better situational awareness", Mr McKay said.
The experimental vehicle was powered by an electric motor and could fly for about 30 minutes.
Its range of about 6km was limited by Civil Aviation regulations covering unmanned aerial systems.
Mr McKay said Christchurch-based Trimble Navigation, where Mr Crowther worked, helped develop the drone and fully supported last week's trial.
He said air patrol volunteers had been monitoring the search for Mr Crowther.
"It was something that we'd been tracking. We knew the investigation was likely to become a search and rescue operation and actually pre-empted it," he said.
Search by remote control
* An aerial drone has been used for the first time in the search for a missing Christchurch man.
* It searched an open tussocky area about 3km by 1km.
* It found no sign of the man but did locate several possible targets that appeared out of place in the tussock environment, allowing searchers to send in ground parties for a closer look.
* The experimental drone was powered by an electric motor and could fly for about 30 minutes.