A 54-year-old pilot from Auckland has been charged with carelessly operating a Boeing 737, carrying 71 passengers on June 22, 2010, when he left for Sydney after the evening civil twilight cutoff time of 5.14pm.
He has been granted name suppression.
The case resumed in the Queenstown District Court yesterday before Judge Kevin Phillips.
The defence argues the pilot's actions of leaving at 5.25pm, with a low cloud ceiling, on a wet runway and with crosswinds exceeding 16 knots, were below the level of carelessness.
Capt Hughes pointed out the pilot operated under insufficient lighting and conditions of near darkness.
"That is why the restriction is in place. It does get dark early in Queenstown compared with other places without that terrain.
"The pilot also has the option of not departing.
"It is absolutely critical that we have that certainty and we don't depart on guesswork."
Capt Hughes said airline pilots should follow procedures and, at the time the Pacific Blue flight took off, conditions for alternative manoeuvres in case of emergency were not met.
"It's not just me saying procedures are important ... They shouldn't be dismissed off-hand."
The pilot's common sense and experience did not give him permission to disregard these procedures, he said.
"A reasonable pilot does not disregard the control tower weather report.
"They had provided a report and [the pilot] must abide by it."
A pilot can exercise his own judgement, he said, but when taking a more conservative approach.
The defence claims the aircraft's lighter-than-normal weight of 59 tonnes meant it would be able to reach the required altitude even if one engine failed.
A return to Queenstown had been ruled out due to fading light.
Capt Hughes, when cross-examined by defence lawyer Matthew Muir, regarded the pilot's use of a Boeing chart to calculate the plane's turning performance in case of an engine failure as "flawed decision-making".
"The chart is not being used for the purpose it's intended.
"You could infer from this chart and refer backwards, but that's not what it's designed for."
Mr Muir argued decisions made by the pilot were based on "sensible and reliable conservatisms".
The case resumed yesterday after a break of three months and is expected to last a further two weeks.
