A Virgin Australia flight bound for Melbourne made an emergency landing after a suspected bird strike shortly after departing Queenstown. Video / NZ Herald
Bird strike has “historically been a major hazard” at Hawke’s Bay Airport, but work ramped up over the past six years has reduced that risk.
On Monday night, in a frightening incident above Queenstown Airport, a Virgin Australia Boeing 737 engine appeaed to catch fire following a href="https://www.nzherald.co.nz/business/bird-strikes-explained-how-common-are-they-in-new-zealand/VO4QR52M5FAMFE6SXBTGC6CZME/" target="_blank">suspected bird strike shortly after take-off.
Passengers reported hearing a bang before seeing flames out the window. The plane, initially bound for Melbourne, made a safe landing at Invercargill Airport with no injuries.
Hawke’s Bay Airport, which is surrounded by wetlands and estuaries, has introduced plenty of its own measures to reduce the potential risk of bird strike incidents.
A Hawke’s Bay Airport report stated native birds did not pose any real threat to planes, but birds such as Canada geese did.
“Weighing around 5kg apiece, they can do serious damage to jets, propellers and aircraft windscreens,” a 2019 airport report reads.
Last Saturday, Birds NZ member Lynne Anderson ran a survey of Canada geese only a few hundred metres south of the airport’s runway, in an area called Southern Marsh.
She and a census partner counted 428 of them, and she said “there has always been a lot of Canada geese” in that area close to the airport.
A Hawke’s Bay Airport report from 2021 stated “bird strike has historically been a major hazard” for the airport because it was close to protected wetlands, coastal habitats, and an estuarine breeding ground.
A lot of work has gone into reducing that risk in recent years — with success — starting with a Wildlife Management Plan commissioned in 2018.
“[That plan] gave us a better understanding of the natural instincts and behaviours of our birdlife, and we are now deploying this knowledge to manage bird populations in a gentle and effective way ... in the past year, we have successfully reduced bird strike at Hawke’s Bay Airport by 14%,” the 2021 report reads.
The safety measures in place
A Hawke’s Bay Airport spokeswoman said the safety measures now being used to reduce the risk of bird strike fell into two broad groups — passive and active.
“Active measures include the likes of remote-operated gas cannons and pyrotechnics.”
Hawke's Bay Airport has measures in place to deal with the risk of bird strike. Photo / Warren Buckland
Gas cannons, also known as bird scare guns or gas bangers, are a common tool that create loud noises or screeches, which can mimic predators, to scare away birds.
Similarly, pyrotechnic devices are also frequently used near airports, and involve a cartridge being fired into the air that explodes at a certain height, causing a loud noise that scares away birds.
In terms of passive measures, the spokeswoman said they used “pasture management to minimise seed heads and other food sources” close to the airport.
Grass surrounding the runway is also kept at a fairly long height to deter insects, which birds like to feed on.
“The [Wildlife Management Plan] is regularly reviewed against industry best practice and for developments in mitigation practices,” she said.
“We also take close interest in off-airport activities such as urban and environmental developments and local government land-use changes that could influence birdlife populations and migratory patterns.”
Canada geese weigh about 5kg and can pose a risk to planes. Photo / Andrew Warner
The airport said it did not keep figures on the number of bird strike incidents during take-offs and landings.
Air New Zealand, the main commercial airline that uses the airport, declined to share its bird strike figures when approached by Hawke’s Bay Today.
Bird numbers are also constantly monitored around Hawke’s Bay Airport by the airport’s firefighting team.
How common is bird strike?
New Zealand Aviation Wildlife Hazard Group (NZAWHG) chairwoman Lizzie Civil told the Herald New Zealand did fairly well with bird avoidance, and its bird strike rate at airports was about four in 10,000 aircraft movements.
She said aircraft engines were designed to withstand ingesting birds, and tested with frozen chickens or turkeys, but larger animals or a flock of them could destroy engine components as they were sucked through.
Twin-engine aircraft are also designed to fly safely on one engine in case of an emergency.
Birds of primary concern are large in size or flocking birds that are slow flying.
Most bird strikes happen between 50-800ft (15-243m) on take-off and landing, according to the Civil Aviation Authority.
Gary Hamilton-Irvine is a Hawke’s Bay-based reporter who covers a range of news topics including business, councils, breaking news and cyclone recovery. He formerly worked at News Corp Australia.
