He flew through prohibited airspace at lunchtime and landed as soon as he realised his mistake.

‘It was a schoolboy error,’ Mayer’s supporter Jiri Dlask said. ‘The problem was we had two different instruments. One said we were clear of airspace, but the official Flymaster said we weren’t.’

When athletes are close to airspace their flight instrument will warn them with a buzz or an alarm. In this case, when the warning came it was cross-checked with the second instrument, which showed them to be in clear air.

However, the data on the second instrument was incorrect.

‘We landed here, and now we must hike up to 2,600m to launch again,’ Dlask said. ‘We continue in the race. We have made a great job so far, and this mistake is a schoolboy error on our part.’

Photos by © zooom / Honza Zak