Lots of patience and free time

From Daily Mail:

The undercarriage retracts and the controls work, although the levers are so small they have to be operated with a pair of tweezers. Young C Park, from Honolulu, took three years and 6,000 hours to complete the model. Cut away on the left side to show the internal workings, all the sections were machined from common aluminium roof flashing. The metal is annealed to the proper softness, making it easier to form and carve.

Mr Park, 77, used more than 50ft of aluminium, reforming and shaping it on a lathe until he was happy with the result. The metal was usually moulded over a wooden support, but for the large area of the skin behind the cockpit he used the ball of his foot to get the correct shape.