"You could see this plane coming in to land - it would have been between the [Southwestern] motorway and the end of the runway - then suddenly the other A320 just moved out into the runway," the witness said.
"I thought, 'that's close', but it just paused on the end of the runway - for about 10 seconds. Then it just gasses and starts rolling down the runway to takeoff speed."
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The man said the incoming plane had passed above him, and was about 150m over Puhinui Creek and 200m from the runway when it "shoved its wheels up and did an aborted landing and jacked itself up really, really steep".
By then, the departing A320 was lifting off about two-thirds of the way down the 3.5km runway, meaning both aircraft were climbing before the domestic flight peeled off to the south and the other turned north.
"Usually planes are about 3km apart, which is how they space them when they are landing, [but] these things would have been barely more than a 'k' [kilometre] and a half apart, which would have been well outside the guidelines."
A passenger who contacted the Herald said it felt "a bit close for comfort".
Passengers of the the Christchurch-bound flight had been told they had to wait for a plane to land before their A320 could take-off, she said.
"Then, as we turned onto the runway, you could see another plane coming into land, it actually looked closer than the initial one we gave way too.
"I did think, 'that's a bit close for comfort, it must be a small one that doesn't need as much of the runway to stop, and I hope we get our arse moving'.
"Even the take-off was different," the woman, who described herself as a frequent flyer, said.
"I actually thought the take-off was not how it normally felt. During and after take off I counted more aircraft in the air than I ever had before."
An Air New Zealand spokeswoman said its pilot was acting under instructions of air traffic controllers, so the incident was not an aborted landing.
"Air Traffic Control requested the pilot of NZ792 [from Adelaide] perform a go-around as the departing flight had yet to clear the runway," she said.
"As per standard operating procedure, the pilot applied thrust to increase the aircraft's altitude. Once the aircraft was established in its climb, the landing gear was retracted. This is a routine procedure and safety was not compromised at any stage."
She would not say how many people were on either aircraft, because it was "not relevant" in the absence of a near-miss.
Airways Corporation communications manager Philippa Sellens, whose organisation runs Air Traffic Control, said there was "no loss of separation" between the aircraft but would not disclose required separation distances.
The Civil Aviation Authority regulator said Air New Zealand reported the incident as a minor occurrence, even though its pilots were performing standard procedure under Airways' instruction. "There is no doubt it would have looked more dramatic than a normal landing," spokesman Mike Richards said.
Runway scare
Incoming: Air New Zealand Flight NZ792 from Adelaide - Airbus 320 configured with 168 passenger seats.
Departing: Air New Zealand Flight NZ545 for Christchurch - Airbus 320 configured with 171 seats.
