The Tall Tale of the Unique Enormous Hughes H-4 Hercules The concept behind the H-4 arose sensibly enough from the strategic bottleneck facing the United States when it entered World War II. Here’s What You Need to Remember: For every legendary airplane like the F-16 Viper or Il-2 Shturmovik that sees large-scale production, history is littered with dozens of promising projects that burned through budgets and deadlines only to produce a handful of prototypes. But perhaps no such failed project still looms in the public consciousness quite like the unique enormous Hughes H-4 Hercules, memorably misnamed the “Spruce Goose.”