But ... it DID fly
There’s been some debate over the last couple decades about whether the HK-1 Hercules/Spruce Goose stayed in ground effect during it’s “flight”, with some doubt cast on whether it could really fly.
Not that being limited to staying in ground effect is a bad thing, the Sovs had good working ground effect designs. It’s just that the HK-1 couldn’t survive the rigour of medium and long range ground effect flights, especially in an open ocean environment.
See my response at #38. It "flew" like Obamacare "works."