Planes from Heathrow have been stopped from taking off by bees and wasps nesting in vital speed gauges.
The insects got into planes run by BA and Virgin when flights were reduced in the pandemic, the Air Accidents Investigation Branch found after a probe into three incidents at the airport last June.
A BA Airbus A320-232 abandoned take-off after the captain’s speed reading showed as less than the co-pilot’s. An inspection found the pitot probe was blocked with a “solid soil-type material”.
The next day a BA A320 parked in a bay nearby had a series of error messages on its flight display, caused by similar blockages, and the problem also forced a BA 777 to abandon take-off. The AAIB found eight planes in all were affected and sent samples to the Natural History Museum for analysis.
Wall mason wasps were found incubating in a BA Airbus 319 and there was an infestation of the hairy-toothed small leafcutter bee in a Virgin Airbus A330
The AAIB report said insect blockages were “not a new hazard, but one likely exacerbated due to the unusually low operational tempo in the pandemic”.
It added: “The pitot probes provided an ideal construction site for nests.”
BA said that at no point was the safety of customers or crew at risk, adding: “Safety is always our highest priority.”
