Up to 200 microlight owners will be notified after a mechanical fault caused a retired top-dressing pilot with 13,000 flying hours to plummet to his death near Inangahua Junction in Buller District.
The inquest into the death of Darrell Peter Williams, 60, of Carters Beach, Westport, was held in Greymouth yesterday.
Coroner Richard McElrae said Mr Williams, flying a Sky Arrow 450 T, took off alone from Westport Airport about 10.30am on March 15, 2009.
Fellow flier Nigel Cleine and a passenger followed in another microlight about 10 minutes later, both heading to Murchison.
About 10 minutes after take-off Mr Williams contacted Mr Cleine to tell him to head through the Buller Gorge because the cloud around Denniston was "claggy".
Near Berlins, he contacted Mr Cleine again, saying "Nigel, I'm in trouble," then in another message he said, "losing control, going down over Whitecliffs".
Two recreational fishermen in the area saw the plane in trouble and a farmhand at Whitecliffs watched the impact, saying it hit the ground and disintegrated. There was no fire.
The farmhand was first to the scene and rendered assistance to Mr Williams, but was unable to revive him.
Civil Aviation Authority (CAA) crash investigator Alan Daly told the hearing the microlight had its annual inspection only a few days before the crash and was marked as satisfactory; the next inspection was due a year later.
CAA had a team of five investigators working with a Sky Arrow specialist from Holland to explain why the plane crashed.
Mr Daly said after the wreckage was dismantled it was discovered the elevator control rod was fractured and fatigued.
"This would not have been visible during the annual inspection or in a pre-flight check."
When CAA discovered the fatigue it made contact with the two other owners of similar planes in New Zealand and tested their aircraft, but no cracks were discovered.
"We attempted to contact the manufacturer in Italy, however they had gone bankrupt."
Another company had since taken over manufacturing the part.
Mr McElrea supported a CAA decision of notifying global organisations about the Inangahua crash, with close to 200 Sky Arrow microlights in the world.
- The Greymouth Star