HK-1
Why is the HK-1 also known as the Spruce Goose? You see, it was made almost completely out of birch. This was meant to be a transatlantic transport jet during WWII, but it was not completed on schedule. This was only ever flown once by the US military. Only a single prototype of this model was built.
HK-1
ADVERTISEMENT
Blohm And Voss BV 238
This is a German flying boat that was created and flown in 1944. Yes, this is yet another jet from the Second World War. The Blohm and Voss BV 238 was the heaviest aircraft built back then at 120,769 pounds. It took too much money and effort to build it, which is the reason they only ever made one unit.
Blohm And Voss BV 238