It’s quite remarkable how many weather balloons (‘radio sondes’) are released each day in the UK. (In 2017 the UK Met Office stated that they released 4,300 each year).
Some of these are bound to be spotted by air traffic.
https://sondehub.org/ shows some known balloons.
On airprox 2022276 (https://www.airproxboard.org.uk/Documents/Download/1938/80fceb88-4fb1-4324-a296-c7d24b78e59e/2924) the pilot suggested that the item they saw
“could have been a balloon or an egg-shaped drone.”
Despite the UKAB’s stated policy to the contrary, and my protestations (below) they classified this as a ‘Drone’ airprox.
The BBC included it in their article about balloon airproxes though. Stansted Airport: Balloon near miss recorded by Boeing 737 pilot - BBC News
Perhaps, given this new found balloon press attention, UKAB will be more likely to classify airprox reports like this as ‘Balloon’ or ‘Unidentified object’? We can only hope!
My response to UKAB on this airprox report:
Using the Airprox Board’s stated methodology “The Board adopts a pragmatic approach wherein if a pilot can positively identify the object as a drone (e.g. number of rotors, recognition of a particular type) then the reporter’s identification is taken at face-value. If a reporter can only describe the object in generic terms (e.g. a rectangular object) then UKAB classify it as an unknown object” this should be classified as ‘Unknown Object’.
The pilot reported that the item was ‘either a balloon or an egg-shaped drone’. The pilot is anything but definitive that he saw a drone and does not include the number of rotors, doesnt recognise a particular type, etc.
Furthermore, egg-shaped drones don’t really exist. The PowerVision Power Egg drone was released in 2015 (an age ago in drone terms) and sold in small numbers. It is not brown, and, whilst it is egg-shaped when closed up on the ground, it is very distinctively (and non-egg) shaped when flying - with four protruding arms, and legs.
The PowerVision PowerEgg was only available in white.
Party balloons are by their very nature egg shaped.