Pacific Blue says the pilots of a plane that may have breached flight rules when taking off from Queenstown airport have been stood down.
The Civil Aviation Authority is investigating after the plane departed in darkness and bad weather on June 22, potentially endangering 140 passengers and crew.
Planes must depart no later than 30 minutes before twilight from the airport, which is surrounded by mountainous terrain and has no radar or runway lights.
Pacific Blue said today the pilots had been stood down, which it said was standard practice in such investigations.
It said the Boeing 737 took off "a few minutes" after daylight hours, and the company was cooperating with investigators.
The flight had been scheduled to leave at 4.30pm, but apparently did not depart until 5.25pm - 20 minutes past the 5.05pm cutoff on one of the shortest days of the year.
CAA spokesman Bill Sommer said the flight "appears to have taken off late" and investigators would speak to the pilot, the airline and witnesses.
"We're determining what happened and the circumstances around it," he said.
The visual flight rules at the airport were there as a safety precaution, Mr Sommer said.
"If anything does happen, they've got sufficient time to return to the airfield and land."
Airlines operating out of Queenstown are responsible for enforcing the flight rules.
PM WANTS ANSWERS
Prime Minister John Key today said he wanted answers over the takeoff.
In Wellington this morning, Key said he had just heard a second hand briefing on the case.
"It sounds as though it's a very unusual set of circumstances and if the reports are correct then it would be extremely worrying," Key said.
"It's vitally important for New Zealand's reputation and image that the high standard of air safety is maintained on commercial flights."
Key said the reports sounded concerning.
"We'll be wanting to get answers to some fairly obvious questions," he said.
"It's obviously critically important that New Zealanders feel safe when they are travelling on commercial aircraft."
Witnesses told RNZ the plane flew dangerously low in dark skies.
Harbour master Marty Black, one of at least four witnesses, says the aircraft never climbed as it should, but instead flew at under 1000 feet as it tried to negotiate its way through mountains in thick cloud.
"It couldn't have been above a thousand feet, it was low, bloody low, never climbed at all," he said.
Another witness Alan Kirker said he first heard unusual noise.
"I kept watching it and watching it."
It banked around the golf course and flew low down the lake.
"I thought, Jesus, man, it was banking almost on its side."
- NZPA and Stuff