Generally, aircraft and water are not something any pilot should deal with at the same time. But that did not prevent Convair from merging the two. Essentially a supersonic boat-plane hybrid, The Convair Sea Dart is rather dangerous. Soon after the U.S. Navy’s Flying Pankake failed, this was the new development was in the works.
The Sea Dart was developed so that it could use the water as its runway. However, after a tragic accident that took place during a public demonstration, claiming the life of Charles Richbourg, the Sea Dart was abandoned immediately, thankfully.
Everyone said it couldn't be done but then Goodyear (the tire company) came along and proved everyone wrong. The plane prototype was about to get the green light, but sadly for the giant flying machine that never happened. When the U.S. military cottoned onto the fact that this plane wouldn't be of much use in the army, the idea was quickly discarded.
Armies can't really have planes popping like balloons up there. It doesn't sound too practical. They were right, and this Inflatoplane was never seen again.
FLS Microjet (flying) and BD-5 Propeller
Possibly the most functional of planes on the list, the FLS microjet was created by a small experimental (keyword) aircraft and home building company called Bede Aircraft. The plane went up in popularity during the '70s and became quite the sensation. Still, it wasn't particularly practical and found its place on the screen instead.
You might know this plane from the iconic Bond film "Octopussy." The tiny plane measures slightly over 5 meters. Don't underestimate it though, it can reach speeds of up to 515 km/h with a range of 370 km. With that said, it's still better off in a Bond film.
Kamov KA- 32
Developed by the Bureau of Russian Helicopters' Kamov, the Ka-32 is a product of the military Ka-27, and its variants are used for a number of missions for heavy-lift cargo operations. firefighting, and medevac.
This is a highly distinctive design that stands out like a sore thumb. While it may get the job done, this aircraft looks like a giant alien bee as it hovers above the ground. Designers weren't exactly thinking of aesthetics when they made it.
The Belfast-build SC.7
The Belfast-build SC.7 is a high-wing turboprop with 19-seats that was used primarily for cargo transport and, due to its somewhat box-like shape, it became known by pilots as "the shed."
Some 153 models were manufactured between the years 1963 and 1986. While the Skyvan demonstrated itself as a useful workhorse it has historically topped lists as one of the ugliest aircraft ever made.