It should be no surprise that this flying machine also got the nickname, “the flying banana,” this multi-purpose helicopter used wheels, floats, and skis and even had a winterization feature that allowed it to function at ridiculously low temperatures ( -65 Fahrenheit.)
Piasecki produced the H21 as an Arctic rescue helicopter, which makes sense considering its fantastic cold-proof functionality. But even with all those capabilities as well as the fact that it was equipped for 12 infantrymen or 12 stretchers, and two medical attendants, the helicopter only was in operation between 1952 until 1959. Did it have to do with the ridiculous shape? It’s possible.
Dornier Aerodyne
Engineer Alexander Lippisch was in charge of the Dornier Aerodyne, a wingless VTOL bot-controlled winged aircraft. The thought that Lippisch had conceptualized was for the plane was to merge lift and thrust production into a single unit and flow channel. Lippisch designed it to be a land or ship-supported drone for aerial reconnaissance.
Measurements-wise, the Aerodyne was 18 feet long and 6 feet wide. Lippisch ended up being part of the Dornier team that produced only one prototype. For some mysterious reason, the first flight was in September 1972 and never again as it retired two months later.
EL/M-2075 Phalcon
According to FAS, the EL/M was the most advanced airborne early warning and control system. Had it not been for the clown-style nose of the EL/M, it would just appear to be a regular 707 Boeing. The chief objective of the plane was to serve as an intelligence provider to maintain air control and conduct surveillance.
The EL/M-2075 is a solid-state conformal array radar system for use on a 707 Boeing. While it was super-advanced, design-wise, people had an issue with the strange-looking nose making the Phalcon looking very strange. You can't win it all.
Sikorsky CH-37C Mojave
Introducing this bug-eyed monstrosity; The Ch-37C was a huge, heavy-lift helicopter, that experienced its first-ever flight in 1956, it was also one of the last helicopters to use a piston engine, which was even bigger, heavier, and sadly less powerful than the turboshaft engines. It wasn't all bad though, as the helicopter did help to recover spy satellite film capsules that dropped from space via parachute.
It did provide some decent services but it was terribly strange-looking, which, as it might come as a surprise, is of somewhat importance, even for NASA.
LTV XC-142
Another experimental gem we have here. The XC-142 was a tri-service tilt-wing aircraft created to investigate the operational suitability of vertical/short takeoff and landing transports. After the first transitional flight with vertical take-off that took place in January 1965, there was some hesitation over whether or not to continue.
The vertical take-off that resulted in the helicopter being changed to forward flight and ultimately land vertically was perhaps a little too complicated. Five models were manufactured, as a large, boxy fuselage with a tilted rear area featuring a loading ramp. The wingspan was 67 feet and 58 feet long overall. After the five models, they ceased to produce it.