Aviation safety regulators in Australia are warning airlines to watch out for wasps, not for their sting but because their nests can clog a critical sensor pilots depend on to gauge airspeed at takeoff.
The population of Key Hole wasps, a type of mud dauber, has grown in the past decade at Brisbane International Airport and poses an urgent danger unless aircraft operators take precautions. The threat is currently isolated to the Brisbane airport but could spread, the regulators said.
“Pitot tubes or static ports blocked (or even partially blocked) in flight can cause total loss of airspeed or altitude indication. This is classified as hazardous. Misleading and/or malfunction without warning can be catastrophic,” the Civil Aviation Safety Authority (CASA) said in a Feb. 10 bulletin.
Pitot tubes are used on aircraft as speedometers, measuring the airflow rate that is critical to keep pressure on the wings to maintain lift.
In 2013, an Airbus A330 had to abort takeoff in Brisbane due to an airspeed failure that was later attributed to the pitot probe being almost entirely obstructed by residue from a mud nest. The number of wasps has increased significantly since then.
Investigators at the time indicated a mud dauber wasp nest that can completely block a pitot tube takes less than two hours to build, but CASA said anecdotal evidence suggests the wasps can significantly block a pitot tube within 20 minutes.
CASA recommends aircraft operators install pitot and vent covers anytime the aircraft is parked, ideally within 30 minutes of engine shutdown to allow enough time for the metal to cool.
Maintenance personnel should regularly check the probe covers for damage and switch off lights in unattended bays or aircraft when possible. And don’t try to physically remove the wasps because they sting, the alert said.