A reopened inquiry into a helicopter crash near Queenstown has uncovered "too many ways" pilots can get around requirements that they be medically and mentally fit to fly.
As a result, the Transport Accident Investigation Commission has asked the Ministry of Health to add safety-critical occupations to a person's records in an under-development national electronic health database.
It also wants doctors to be reminded of their obligation to inform authorities when such a person's health could affect their job.
Flight student James Patterson Gardner, 18, and instructor Steven Combe, 42, died after their Robinson R44 helicopter crashed near Queenstown in 2015.
TAIC's initial report into the crash last year blamed the concerning issue of "mast bumping" for the crash.
However, five days after that report was released, the coroner informed TAIC of Mr Combe's medical history, of which it had been unaware.
The former British marine suffered from "depression with anxiety component" after spending two years flying in Papua New Guinea. On returning to New Zealand he renewed his pilot's medical certificate but failed to mention seeing a psychiatrist or any medication he took.
TAIC said it was likely Mr Combe would have been fit to fly when he got his medical certificate and "very unlikely" medical factors contributed to the accident.
However, the investigation revealed there were too many ways for pilots to circumvent the process designed to stop them flying if they weren't medically fit.
The system relied on pilots being honest about their medical history and the examiner doesn't have to contact their GP.
Pilots could also minimise the risk of losing their licence by using different GPs - one to declare a clean record and another to deal with problems they want kept confidential.
GPs were also not generally aware they had to inform the Civil Aviation Authority of pilots' mental health.