[GH85Carrera]

13,000 horsepower—a staggering amount of raw power packed into the Pratt & Whitney R-4360 radial engine. To put this into perspective, the legendary B-17 Flying Fortress had only 4,800 horsepower. That means the XF-12 Rainbow, powered by four of these beasts, had nearly three times the muscle of the B-17. The result? A mind-blowing power-to-weight ratio of 0.128, superior even to its competitor, the Hughes XF-11 at 0.103. This engine wasn’t just about brute force; it was a technological masterpiece, propelling the Rainbow into aviation history