Civil Aviation Authority investigators have yet to find an obvious cause of a fatal microlight accident which killed two people in Timaru on Friday.
Veteran pilot Alfred "Jack" Mehlhopt, 86, was flying the New Zealand designed and built Bantam B22 with Canterbury Senior Sergeant Randel Hohi "Randel" Tikitiki, 51, when it crashed on farmland 11km north of Timaru.
They had taken off for a routine training flight from Richard Pearse Airport, in Timaru around 7pm, but crashed on farmland 30 minutes later.
CAA safety investigators at the scene today have not yet found an obvious cause of the crash, spokesman Mike Richards said.
"An extensive process of ruling out variables and possible causes is now being undertaken.
"Two investigators will continue to comb through the wreckage looking for clues that might explain the cause of the accident.
"It is expected that investigation will continue through until Monday. Several interviews with eye witnesses still need to be conducted."
Mr Mehlhopt's aviation documents and medical certificate were all up to date and in order, Mr Richards said.
Once the physical inspection and detailed photographic record of the accident scene was completed, the wreckage would be transported to Wellington for further examination.
South Canterbury Microlight Club president Tim McLeod yesterday said Mr Mehlhopt's death was an enormous loss to the aviation community.
"He was a true icon of aviation really and a hell of a nice man, as were both of them."
Mr Tikitiki had been a member of the club for several months and was under training, Mr McLeod said.
Mr Mehlhopt's family released a statement describing him as a loving father, uncle, grandfather and great-grandfather who would be missed by his friends and family.
"Jack was an extremely experienced aviator having held a pilots licence since the age of 16.
"Aviation was his lifelong passion. The fact he is never coming home again is something that is very hard to get your head around."
The New Zealand Air Line Pilots' Association in 2012 awarded Mr Mehlhopt with the Greg Vujcich Memorial Award for Excellence in General Aviation Instruction.
They noted he had sent at least 300 students on their first solo flight - some of which had gone on to become air force officers, airline pilots, and flight instructors.
Once when asked why he did so much, Mr Mehlhopt said he had never forgotten the support he had received early on in his flying career, and believed he had a duty to make his own contribution.
In 1996, he was honoured by the Federation Aeronautique Internationale with its Air Sport Medal in recognition of his outstanding contribution to general aviation.
Canterbury Police district commander Superintendent Gary Knowles said that Mr Tikitiki's death had rocked not only the community in Timaru but everyone at Canterbury Police.
"Randel was a valued friend and colleague to many in New Zealand Police and a respected member of the community in Timaru."
The father of two twin girls had worked for police for 28 years, following in the footsteps of his father, Mr Knowles said.
"His professionalism and passion for the district will be sadly missed. The thoughts and prayers of everyone at Canterbury Police are with the friends and families of Randel and Jack, two men who made a real difference to so many lives."
Mr Tikitiki's family also released a statement paying tribute to the loving father, avid fisherman and dedicated police officer.
The men's deaths have been referred to the Coroner.