An easyJet flight travelling at more than 500mph and packed with holidaymakers missed a rogue weather balloon by as little as 20ft, a report has revealed.
The A320 plane carrying up to 180 passengers on a flight from Alicante in Spain to Manchester had the close call while flying at a height of 38,000ft.
The incident happened just before 1.45pm on August 25 this year as the plane was starting its descent while around three miles north east of Luton.
The UK Airprox Board which assesses near misses in UK airspace rated it as a Category A incident where there was a serious risk of collision.
The report by the Board was unable to find out the origin of the balloon which is thought to have blown off course from its launching point.
Checks revealed no official Notice to Airmen records, known as NOTAMs, warning of any balloon launches in the area at the time.
The pilot was said to have observed the white balloon with ‘red equipment suspended from it’ for around two seconds before it ‘passed to the left and just above the aircraft’.
The near miss was immediately reported to air traffic controllers at Swanwick, Hampshire.
The pilot initially told controllers that the plane had missed the balloon by 20ft, before changing the estimate to it being 30ft away horizontally and 10ft higher than the aircraft.
The official report by the pilot described the risk of collision as ‘medium’.
The Board report said: ‘Analysis of the radar by Safety Investigations indicated that there were no associated primary or secondary contacts visible on radar, reference the sighting, at the approximate time of the event.
‘Following the pilot’s report, the controller broadcast details of the sighting to other aircraft on frequency in the vicinity, but there were no further reported sightings.
‘Safety Investigations have not been able to identify any NOTAM’d balloon launches, or any other published activity, which could correlate with this sighting.
‘In the Board’s opinion the reported altitude or description of the object were sufficient to indicate that it was probably a balloon.’
The report added: ‘The Board considered that the pilot’s overall account of the incident portrayed a situation where providence had played a major part in the incident and/or a definite risk of collision had existed.’
The Met Office launches around 4,300 weather balloons every year across the UK with many designed to collect data from heights of 65,000ft to 115,000ft.
Most are designed to burst when they reach a certain height and then float back down to earth by parachute so equipment can be used again.
They are only supposed to be launched away from the flight paths of aircraft to avoid the risk of collisions.
The report gave no indication whether the balloon was believed to have belonged to the Met Office or was launched by a private individual or another institution.
An easyJet spokesperson said: ‘We are aware of the report and fully supported the investigation.
‘After the sighting, the pilots followed the relevant operating procedures and at no point was the safety of those onboard compromised.
‘The safety and wellbeing of passengers and crew is always easyJet’s highest priority.’