The plane ran out of kerosene
On Friday evening, the mission doctors John reached the destination airport Frankfurt with a delay of almost two hours. Due to an empty fuel tank, the Airbus had to make a stopover in Paris. According to the pilot, several thunderstorm fronts over the Atlantic would have required a significantly longer flight path. However, Flightradar 24 does not verify this claim. So the truth will probably never come to light.
The Johns’ schedule includes about 15 public and non-public appointments. On Monday evening, Dr. John flies to London to attend two important meetings in southern England.