Wasps: another problem for aviation

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Brisbane, Australie (CNN) – A small insect that has escaped Australia’s strict biosecurity controls is multiplying and threatening aircraft safety at Brisbane airport.
Native to Central America, South America and the Caribbean, the keyhole wasp caused problems at the airport in 2013, when it forced an Etihad Airways A330 bound for Singapore to do halfway. -tour a few minutes after the start of the flight.

Once on the ground, maintenance workers discovered that the pilot’s pitot tube – the hollow instrument on the outside of the plane that measures speed – was almost completely blocked by mud, according to a report from the Australian Bureau. transport safety.

For wasps, the Pitot tubes are the perfect cavity for building a high-speed nest – the Etihad aircraft was only on the tarmac for two hours before the interrupted flight.

“We have anecdotal reports from the Brisbane ground crew that a plane may have arrived at the boarding gate and within two or three minutes a wasp will be flying around the nose of the plane looking at the probe, ”said Alan House, an environmentalist with Eco Logical Australia.

A keyhole wasp perched on a 3D printed De Havilland Dash-8 Pitot probe.

MAISON ET AL (2020) PLOS ONE

House worked with experts from Brisbane Airport, Australian airline Qantas, and environmental consultancy firm Ecosure to produce one of the world’s first studies on the impact of wasps on pitot tubes. Commissioned by Brisbane Airport Corporation, it was published this week in the open access journal PLOS ONE.

Researchers say that without proper management, there is a risk that the wasps could travel to other Australian airports – and even neighboring countries with the right semi-tropical conditions for them to thrive.

“When we did some background research, we realized that it wasn’t just an inconvenience, that you just had to clean up these things and drive out the wasps; it could actually lead to major accidents, ”House said.

An important instrument

Mounted on the front of planes, Pitot tubes perform the important task of returning information to the cockpit about the speed at which air passes through them. This indicates the speed at which the plane is moving – too slowly and there is a risk of stalling, too fast and it could malfunction in other ways.

When the Pitot tubes are not functioning, the A330 automatically switches to manual mode, forcing pilots to take control. This is what happened with the Etihad flight, and ultimately why the pilots turned around.

There have been no major incidents at Brisbane Airport due to the wasps, but accidents elsewhere have been linked to the insect.

Airplane pitot tubes, which measure speed, are ideal places for wasps to build nests, researchers say.

JOKER / Hady Khandani / wool stone image via Getty Images

For example, Birgenair Flight 301 crashed off the Dominican Republic in February 1996, killing 189 passengers and crew. The accident report stated that the “probable cause” of the blockage of the Pitot tube was “mud and / or debris from a small insect” which entered while the aircraft was on the ground.

CASA has advised airlines to cover pitot tubes while waiting at Brisbane airport. However, this is not mandatory, which is why blockages still occur. A total of 26 incidents were reported between November 2013 and April 2019, according to the Brisbane Airport study.

Clever wasps

The first keyhole wasps were detected at the Port of Brisbane in 2010, although it is possible that they arrived as early as 2006, according to the study. It is not known how they got to Australia – likely by boat, House said.

They are believed to have been at Brisbane Airport since 2012, and they do not appear to have spread to any other Australian city, although they were seen at Emerald Airport, a small regional hub in more 800 kilometers (500 miles). , according to CASA.

For the study, the researchers used 3D printers to print replica Pitot tube probes on Boeing 737s and 747s, Airbus A330s, and small Dash 8 airlines commonly used by regional airlines. They were positioned at four locations around the airport and monitored for 39 months.

During that time, there were 93 fully blocked probe instances, and nearly all of them were built during the warmer months between November and May.

Most of the nests were close to the grassed area of ​​the airport, according to study co-author Jackson Ring, Wildlife Management and Planning Coordinator at Brisbane Airport. Wasps pick up the caterpillars from the grass and push them into pitot tubes as food for their offspring.

Wildlife managers use targeted organic pesticides to kill caterpillars and have so far succeeded in reducing wasp activity by 50% near international and domestic terminals, Ring said.

“We are treating approximately 120 hectares (1.2 square kilometers) of the airfield, which is a selective way to eliminate this food source and make areas where aircraft are parked and vulnerable to unwanted wasp infestation. for the wasp, ”Ring said.

The introduction of predators, such as birds for example, is not an option for obvious reasons. Before the wasps arrived, Ring spent most of his time trying to scare off wildlife to avoid bird strikes and other dangerous encounters between animals and planes.

Can they be eradicated?

The wasp is not classified as an agricultural pest and is not a vector of human disease, so despite its status as an unwelcome visitor, there is no official government plan to eradicate it, House said.

It is also a very ingenious creature and there is no shortage of breeding sites.

“He can build his own nest if he wants to, he can use old nests of other mud wasps if he wants to, and he can use any nook and cranny.” There are lots of places like that all over the airport, and everywhere, everywhere, basically, ”House said.

“They are very determined. These guys just need to find a nest. Put a caterpillar, lay an egg, seal it. “

An aerial view of Brisbane Airport.

An aerial view of Brisbane Airport.

Glenn Hunt / Getty Images

Like most airports around the world, traffic has dropped significantly at Brisbane Airport during the coronavirus pandemic. Since July, international flights to Australia have been limited by caps for return travelers, and state borders have been closed to contain local outbreaks. The planes were parked for months, with their pitot tubes covered to prevent infestation.

However, on Tuesday, traffic will increase again with the lifting of internal border restrictions – meaning there will be more planes coming and going – creating more opportunities for wasps to cause trouble.

According to the study, lock-shaped wasps are also found in the southern United States and a number of Pacific islands, including Hawaii, Polynesia, Micronesia, and Japan.

Researchers are working with airport operators in Papua New Guinea and Fiji, where incidents have also been reported. They also sent 3D printed tubes and components to Honolulu for similar studies.

House said the researchers didn’t want to make it sound like it’s unsafe to fly out of Brisbane. In fact, he says, it’s safer than a few years ago, when they knew less about the insect.

The keyhole wasp may be small, he said, but their threat to aviation cannot be ignored.

“A lot of attention is being paid around the world to other airport wildlife management issues, especially birds because they are clearly seen as a major danger to flights,” House said.

“Something like a wasp is considered more of a low level risk. The chances of something happening are pretty low, but there is always a chance that it will. “

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