Imagine you were aboard easyJet ’s Sunday evening flight from London Gatwick to Basel. The plane departed over two hours late. The airline blamed air-traffic control restrictions throughout the day; earlier, Ryanair said 15 per cent of its first-wave departures that morning left late because of shortages of air-traffic controllers across Europe .

Yet the plane made good progress. Fifty minutes into the flight all seemed to be going well. The Airbus A320 had descended from its cruise altitude of 29,000 to 15,000 feet.

Touchdown was 10 minutes away, at about 11.15pm local time. Suddenly, though, the aircraft made a sharp right turn and flew an extra 200 miles to Lyon in southern France.

Passengers were told the flight had been delayed “outside of the opening hours of Basel airport”. The airline explained: “Some airports have strict operating times which cannot be extended. As a result we had no option but to divert your flight.

” They completed the journey through the night on buses, taking a further four hours. Passengers waiting at Basel to fly to London on the same plane were told their flight was cancelled. The aircraft flew empty from Lyon back to Gatwick.

Yet several other easyJet aircraft landed at Basel after that time without an issue. What had actually happened was that someone at easyJet HQ had calculated that while the Airbus A320 could land without a problem, it would not be allowed to take off again that night because of the 11pm noise curfew on departure.