The cockpit collision alarm sounded on an Air New Zealand Boeing 737 as it came “face to face” with a light aircraft over Lake Wakatipu last Saturday.
Near Cecil Peak at 4.08pm, Flight NZ647 from Auckland with 106 passengers was performing an unusual manoeuvre which put it on a collision course with a small plane returning with passengers from Milford Sound.
Glenorchy Air owner Robert Rutherford stresses “there was no possibility of a collision” but his pilot took evasive action “as a precaution”, moving “a bit closer to the mountain where he knew the 737 wouldn’t possibly ever go”.
Rutherford’s pilot was flying at about 3300ft – “where he was supposed to be” – on the standard return approach to Queenstown from Milford Sound.
Other Milford flights were following Glenorchy Air and Mountain Scene has spoken to one pilot who witnessed the aerial drama.
Air NZ’s jet came “face to face” with Glenorchy Air at a distance of “probably only a couple of nautical miles”, he says.
“Anything less than five nautical miles is classed as a near-miss because of closure speeds,” the witness says.
The two aircraft were closing at an estimated 270-300 knots, the pilot reckons – that’s 500-550kmh.
Rutherford says the Boeing earlier aborted a landing from Queenstown Airport’s Shotover River end.
The anonymous Milford pilot says what happened next is highly unusual.
When big jets perform a “go-around”, “they get up and out of here to a certain height [so] they don’t conflict with any [other air] traffic”.
Not this time.
Flight 647 flew quite low down Frankton Arm to do a tight 180deg turn over Lake Wakatipu between Cecil Peak and Fernhill to put it on track for another landing at the airport, this time from the Frankton end.
“That’s pretty uncommon,” the pilot adds. “I’ve never ever seen a Boeing do a weird split-arse turn like that.”
Civil Aviation Authority spokesperson Emma Peel says: “This is an incident under investigation.”
Control tower operator Airways Corporation has formally notified CAA, she says.
Airways, Air NZ and Glenorchy Air will now do full investigations and prepare reports for evaluation by CAA’s airspace safety investigator.
An Air NZ spokesperson says Flight 647 performed a “standard go-around procedure” under instructions from the Queenstown Airport tower – “both air traffic control and our pilots were aware of another aircraft in the vicinity”.
“Both aircraft were turning in opposite directions away from each other,” the spokesperson says.
Because of Air NZ’s late response, Mountain Scene was unable to corroborate the airline’s claims by deadline.