Wasps force two passenger jets into emergency landings
Two hours on the ground is enough for flying menaces to damage flying machines
More proof that everything in Australia is trying to kill you: the nation's Transport Safety Bureau (ATSB) has published details of how wasps have caused two passenger jets to make emergency landings.
The good news: the wasps in question are not some kind of giant mutants that can bat a plane from the sky and sting it on the way down, although that would be kind of cool.
Instead the creatures are “mud dauber wasps” (Sceliphron laetum), a species the Australian Museum tells us “are often seen collecting water and mud for their nests, which they commonly construct in protected areas of houses, buildings and rock overhangs.”
And also, it turns out, planes at the airport in Brisbane, the sub-tropical capital of the Australian state of Queensland.
The ATSB report concerns an Airbus A330 operated by Etihad Airways which on November 21st, 2013, flew in from Singapore and spent just two hours and three minutes on the tarmac before heading off on the return journey.
“At 1152 EST,” the report says, “the aircraft was pushed-back for the return flight to Singapore. The captain rejected the initial take-off attempt on runway 01 after observing that there was an airspeed indication failure.”
After checking that redundant systems were in order, the plane again took off and again received airspeed warnings. This time the crew continued the takeoff and made it into the air, but “As a result of the airspeed discrepancy, the autothrust system and flight directors disengaged automatically.” Not long afterwards, “the slat/flap lever was moved from the CONF1 to the 0 (up) position and the flaps began to retract, but the slats remained extended.”
That's bad: slats shouldn't remain out once the plane gathers speed, so “... the crew declared a MAYDAY and decided to return to Brisbane.”
“An overweight landing was subsequently carried out on runway 01 and the aircraft taxied clear of the runway with the aviation rescue and fire-fighting (ARFF) services in attendance. The aircraft then taxied back to the terminal.”
Closer inspection of the plane revealed that one of the airpseed sensors “... was occluded by an incomplete insect’s nest and the nest material was consistent with that of the mud-dauber wasp.”
The report notes that the same problem's since struck a Virgin Australia 737, which returned to Brisbane after also reporting faulty airspeed readings.
Etihad's changed the way it operates at Brisbane airport: it now puts little plastic caps over airspeed sensors. Brisbane airport now conducts weekly wasp inspections, up from its previous monthly efforts, and “Extended the pest management program to include removal of spider webs (spiders are a food source for wasps).” ®