The Civil Aviation Authority (CAA) said charges were laid in 2010, following the incident on January 26 that year, however, the prosecution remained on hold for almost a decade because the former pilot was living overseas.
In the Christchurch District Court last Friday Judge Murray Hunt convicted and fined the man a total of $5750 on one charge of operating an aircraft in a manner that caused unnecessary endangerment and for performing maintenance on an aircraft without holding the appropriate aviation document.
On January 26, 2010 the man was working as a senior pilot for a scenic tourist flight operator, flying between Queenstown and Fiordland.
While taking off from Big Bay, a beach north of Milford Sound, the aircraft's propeller was severely damaged by stones thrown up during the take-off run.
Despite being aware of the potential for damage when landing on strips like Big Bay, the pilot did not conduct any inspection, even a quick "walk-around" of the aircraft after the return to Queenstown, which would have revealed the damage.
He then flew to Milford Sound to pick up a group of tourists, which was when he noticed the damage to the propeller and phoned head office to inform them.
He attempted to minimise the damage by filing down the propeller, a maintenance task only appropriately-qualified aircraft engineers can perform.
Despite not hearing back about the airworthiness of the propeller, the pilot decided to fly back to Queenstown with the six passengers onboard.
After landing the aircraft was immediately grounded by the company's owner.
CAA deputy chief executive David Harrison said the conviction highlighted the importance of aircraft damage being assessed by appropriately-qualified engineers, not by pilots "taking a punt".
"Taking a 'she'll be right' attitude just doesn't cut it when there's damage to critical aircraft components, such as propellers,'' Mr Harrison said.
"Pilots and engineers each have hugely important roles to play in keeping aviation safe, but there are clear lines about the sort of work that needs to be carried out by qualified aircraft engineers.
"In this case we're lucky that there weren't more serious consequences given the seriousness of the damage to the prop."
The former pilot's association with the tourism operator ended shortly after the incident and the company was now under new ownership and management.
He does not currently hold an active commercial pilot licence and to reactivate it in future he would have to pass CAA's rigorous "fit and proper person process", during which the conviction would be a strongly-weighted consideration.
