The near miss took place as the jet - flying from Florence in Italy - was at 1,300ft and coming in to land at Heathrow Airport in May when a pilot spotted the small blue drone.
In the show, the Prince of Wales, 44, invited host and Schitt's Creek actor Eugene, 79, into Windsor Castle, and opened up about the 'hardest year I've ever had'.
Royal protection police have been put on restricted duties amid claims they slept on the job while working at Windsor Castle. Police are now investigating officers at other royal residences.