Vought F7U Cutlass:This article is worth a read from a pure historical perspective. I can't say that I disagree with his picks but 5 is probably too small a number to capture all the mess ups we've had when it comes to fighter design. Don't get me wrong, we've had more success than failure and most of the planes on the list were during a time when we had multiple projects going on at the same time.
The U.S. Navy didn’t have an easy time introducing jets onto the carrier flight deck. One early effort was the Vought F7U Cutlass—known derisively to its pilots as the “Gutless Cutlass.” The Cutlass was not only severely underpowered with its pair of Westinghouse J46-WE-8B turbojets; it was also plagued with immature systems—especially its problematic hydraulics.
Indeed, retired U.S. Navy Rear Adm. Edward Lewis "Whitey" Feightner—a former Blue Angel— told the Smithsonian’s Air & Space Magazine that he offered his resignation on the spot when he was told the team would fly the Cutlass. “The Cutlass could be made into a pretty good flying machine with a few modifications,” wrote F7U-3 pilot John Moore in The Wrong Stuff, Air & Space reported. “Like a conventional tail, tripling the thrust, cutting the nosewheel strut in half, completely redoing the flight control system, and getting someone else to fly it.”
What I mean is that we weren't crippled (in the past) if we got it wrong.
Too bad we can't say the same today.