the largest airplane every build is the hughes h-4 hercules flying boat its 97.5 m wingspan is still 9.1 longer than the next largest plane ever to be built however because it is made of birch not spruce as its populare nickname the spruce goose would suggest the mass of the h-4 is 1.81 x 10^5 kg considerably lighter than any other giant plane. The h-4 was flown only once over a distance of about 1.6 km if the maximum gravitational potential energy associated with the h-4 was 3.78 x 10^7 j how high did it fly