Just when you thought it was safe to re-enter Christchurch airspace this summer - shark!
The pilot of a passenger jet, thought to be an Air New Zealand flight, was on his descent to Christchurch International Airport on Boxing Day when he radioed ground control with an unlikely sighting - a shark flying at several thousand feet.
The fish out of water was identified as a remote-controlled, helium-filled shark that has topped must-have present lists this Christmas.
The 1.44m Air Swimmer toy has a radio receiver attached to its underside and can be operated by remote control over a range of 15m.
Designer-developer William Mark Corporation warns that the shark is for "strictly indoor use only".
A spokeswoman for air traffic control company Airways, Monica Davis, said a pilot had reported the shark and its location about 9km from the airport at 2pm on December 26.
"We advised subsequent traffic of its location, but no-one else reported seeing it."
It was not yet known whether the sighting would be formally logged as an air-safety incident, she said.
The shark's altitude and how close it came to the plane were unclear, Davis said.
The Civil Aviation Authority had not received a report of any shark encounters, but because the Christchurch incident was only a sighting, there is a 30-day reporting period.
Accidents must be reported within 24 hours.
New Zealand Air Line Pilots' Association president Glen Kenny said a helium-filled shark would not pose a serious risk if it was sucked into an aircraft engine.
"The engine probably wouldn't stop, but it would do a bit of damage," he said.
"Helium is an inert gas, so there's no issue in that regard. The biggest hazard would be startling the pilot."
Wayward party balloons had been an air-safety issue overseas, especially in the United States, Kenny said.
He had heard about the Christchurch shark incident and had some experience with the toy, having bought his daughter the 91cm clownfish version for Christmas.
He hoped common sense would prevail as people tried out their helium-filled toy.
"It says it's an indoor toy on the box. If you take them outside and the wind gets them, they can be goneburger, so you've got to be a bit careful," he said.
The Air Swimmer was created by 19-year-old Stanford University student Blake English and has proved to be one of the most popular toys worldwide since its release in July.
They retail in New Zealand for $99 (helium not included) and should not be operated outside, near water or by children aged under three.
The Top Christmas Toys website rates the Air Swimmer as one of the best of 2011, describing it as "great fun for indoor family get-togethers and children's parties".
It recommends users turn off ceiling fans while operating the device "for both safety and control".
Fairfax NZ News