Maybe these bees were too tired to fly for themselves.
A gang of honeybees landed on the wing of a plane used for flight school training at Beverly Airport in Danvers, Mass. At first, the 10,000 or so bees swarmed over the left side of the aircraft, then landed on top of the left wing. The owner of the flight center called police, who said to call local bee removal expert Al Wilkins.
Wilkins used a specially designed vacuum to suck the bees off the plane, and then relocated them to hives where they will produce honey.
Wilkins guessed that the queen may have stopped to rest on the plane, and the other bees congregated around to protect her.