Mud Wasps

Safety, Aircraft, Animals/Wildlife

Monday 31 October, 2016

CASA have issued a warning about the dangers of mud wasp infestation. It can take the little fellers just 20 minutes to build a nest which can block a pitot tube, vent or drain.

Between 2010 and 2015, CASA received about 20 reports of mud wasps affecting large aircraft. There have also been reports from overseas of fatal accidents attributed to wasp nests blocking the pitot tube, resulting in loss of airspeed indication. CASA reminds owners that the danger also applies to light aircraft.

A recent investigation found wasp nests inside the wing of a Cessna 182, in the cavity formed between the rear spar and the flap fairing. There was also a large wasp nest suspended on the flight control cables in the rear fuselage.

Recommendations from CASA

  1. Install pitot/ static and vent covers any time the aircraft is parked.
  2. Consider installing approved fuel vent screens or removable drain/vent covers and engine compartment blanks, as well as installing tight fitting pitot/ static vent covers.
  3. In instances where the aircraft has been stored long term in the open air, remove inspection panels before flight as required to inspect unsealed wing and fuselage cavities etc.
  4. Continually monitor and remove any wasp nesting sites in the general area where the aircraft is stored or maintained in accordance with appropriate insect control procedures.
  5. Be aware that on-ground pre-flight air data module BITE tests and/or computer checks will usually not test pitot probes or static vents for blockages.


All wasp nest and/ or insect infestations and any associated defects or operational difficulties should be reported to RAAus via the Occurrence Management System (OMS).