Police say they were notified about 10.55am of a potential emergency involving an incoming plane.
After the plane landed safely, police were stood down.
On Saturday, a Qantas flight diverted to Christchurch after flames shot from its engines shortly after departing Queenstown.
Sydney-based Kiwi nurse Ange Taranto was in a row 7 window seat on the left of the Sydney-bound Boeing 737.
Following takeoff – just after 4pm – she heard “really loud bangs” that some blamed on landing-gear.
Another passenger, Charlie, headed to Vancouver via Sydney, said he saw flames.
They lasted a few seconds and reoccurred several times, Charlie said.
The plane landed safely in Christchurch to cheering and clapping from the full flight, another passenger said.
A Qantas spokeswoman said QF122 “experienced a suspected engine issue after take-off from Queenstown”.
“The aircraft diverted to Christchurch and landed safely and normally.”
More to come.