KEY POINTS:
Air accident investigators expect few problems in determining the cause of Sunday's crash near Mt Cook that left two pilots with serious injuries.
North Shore Aero Club flight instructor Richard Bateman, 27, and student pilot Nick Eagleson, 33, survived when their Robin R2120 aircraft crashed in the Gammock Range in the Mackenzie Country on Sunday afternoon.
Mr Bateman managed to get out of the wrecked plane with a badly gashed scalp, then freed his companion and made a two-hour, 5km trek down a steep valley to raise the alarm.
He was expected to be discharged from Timaru Hospital yesterday. A hospital spokeswoman said Mr Bateman was well enough to continue his recovery at home.
Mr Eagleson was reported to be in a stable condition at Christchurch Hospital yesterday morning with multiple injuries. Visiting was restricted.
The Civil Aviation Authority (CAA) initiated an investigation into the crash in a brief interview with Mr Bateman in hospital on Monday and both pilots will be spoken to again when they have recovered.
CAA spokesman Bill Sommer said he expected the investigation into the cause of the crash would be a simple one. He doubted investigators would even need to visit the wreckage.
"We've got warm bodies to talk to," Mr Sommer said. "This is not a fatal accident."
Investigators had to rely on forensic evidence gained from clues in wrecked aircraft when there were no survivors.
"In this case, we've got an instructor-pilot and another pilot to talk to.
"We're very hopeful that we'll be able to determine the cause without having to dig around through wreckage," he said.
Mr Bateman was reported to have told his mother soon after he was picked up by rescuers that he believed the aircraft had been caught in a downdraft. Mr Sommer said that would be one aspect investigators would follow up.
He understood Mr Eagleson could remember little of the incident.
"Although they sustained injuries, it's great they survived the accident," Mr Sommer said.
"It's hard work [for investigators] if you're left with a smoking hole in the ground."
Mr Bateman was "pretty experienced" and should be able to provide investigators with plenty of relevant information.
"Hopefully, it will be very simple for us. That's the way we like it."
Removal of the wreckage from the Gammock Range would be up to the aero club or its insurers.
- NZPA
