The Air Accidents Investigation Branch has published a report into an investigation into a series of pitot system blockage events on different aircraft which occurred between 9 June 2021 and 19 July 2021 at Heathrow Airport.
Between 9 June 2021 and 19 July 2021, several aircraft suffered from abnormal pitot/static system events, two of which resulted in rejected takeoffs. The AAIB investigation identified the cause to be the nesting activity of certain species of wasps and bees within pitot probes. The report addresses the likely reasons as to why there was a concentration of such events over a relatively short period of time.
Although Heathrow Airport and the surrounding area was the focus for these occurrences, detailed information on the environmental factors is provided for the operators of airfields at other locations to take into consideration.
Safety action has been taken by the CAA and those airline operators affected to reduce the risk of reoccurrence by introducing additional inspections and changes to the use of pitot covers. In addition, the airport operator is updating its environmental hazard management plan to take into account the findings of this investigation.