British Airways is facing a safety investigation after three of its jets were grounded by insect infestations before taking off at Heathrow over a three day period.
Two of the planes were roaring down the runway when the pilots successfully abandoned take off after realising that vital speed sensors were malfunctioning.
A third jet is believed to have been moving towards the runway when the pilots noted a similar error and returned the plane back to its stand.
Investigations later revealed that insects had crept into the aircraft’s air speed sensors, known as pitot tubes, causing blockages which gave false speed readings.
Similar incidents are known to have caused aircraft to crash in the past because pilots and fly by wire automated systems can become confused by inaccurate airspeed data.
All three of the BA jets are believed to have been on the ground for periods of between three and seven days when the insect contamination happened.
Normally aircraft in storage are required to have special covers over their pitot tubes to help prevent insects or dust getting inside.
The incidents at Heathrow happened between June 9 and 11 this year when temperatures at the airport had soared to 26C, creating ideal conditions for swarming insects.
The most serious involved a BA Boeing 777-200 which was taking off to fly to Accra, Ghana, on June 11.
The jet was rolling down the runway at nearly 100mph when the pilots realised there were ‘unreliable air speed indications’ from all three of their pitot tube systems.
BA statement
Safety is always our highest priority and we, like other operators, are conducting additional checks in line with the CAA’s recommendations.
As the AAIB investigation continues it would not be appropriate to comment further.