Weird and wonderful concepts that even Charles Lindbergh would go on to praise… but just how far could conventional aircraft designs be pushed?
Think you’ve seen it all? Well maybe you haven’t seen some of these radical and unique designs. Experimental aircraft ideas over the past century have varied enormously, but all have had the same goals: to test new design concepts and aerospace technologies which result in more efficient air travel. Of course, even the most basic of aeroplane designs would have looked strange to someone at one period or another in history. But there are some extremely ‘out there’ designs and prototypes of experimental aircraft that were just never destined to take off (if you’ll forgive the pun).
Kicking off our list of aviation oddballs is the NASA AD-1, which incorporated a revolutionary – yet strange - oblique wing design. The term ‘oblique wing’ referred to the non-conventional design of a variable geometry wing; particularly in the case of the AD-1, one wing was swept forward while the other was swept back. The aim of the experimental aircraft was to determine whether by changing the sweep angle of a wing, drag could be reduced at high speeds. By altering the wing position in this way, the centre of gravity over the aircraft could be changed, hence resulting in higher speeds. The AD-1 first flew in 1979, and over the course of the following months the wing was pivoted incrementally, until the full 60-degree angle was reached in mid-1981. Perhaps most interesting about the AD-1 was its capability to take off with the wing perpendicular to the aircraft (in such a way as you might think of a normal wing position), and successfully demonstrate that the wing could be pivoted obliquely from zero to 60 degrees during flight. Although little came of the experiment in terms of future wing design, the programme did successfully evaluate the basic pivot-wing concept and gathered information on handling qualities and aerodynamics at various speeds and degrees of pivot.
Next on our list is the uniquely interesting Vought V-173 ‘Flying Pancake’. The oddly shaped – and oddly named – experimental aircraft was built as an extension design of an equally oddly named experimental fighter aircraft in the United States during World War II: the ‘Flying Flapjack’. Both the Pancake and the Flapjack consisted of relatively flat disc-shaped bodies of an ‘all wing’ design. With designs straight out of a sci-fi film, the Pancake demonstrated the United States’ need for ship-borne aircraft that could take off from short runways. The prototype was constructed from wood and canvas and the tall, fixed main undercarriage combined with a small tailwheel gave the aircraft a 22 degree ‘nose-high’ angle. Famously, Charles Lindbergh once piloted the ‘Flying Pancake’ and commented on its surprisingly pleasant qualities, such as ease of handling and range of capabilities at low speeds.
The McDonnell XF-85 Goblin is next to be featured on our list of the weird and wonderful winged things. The extremely short-bodied aircraft was designed to be a parasite fighter that could be dropped from the bomb bay of a Convair B-36 bomber following World War II. As a result, the design was drawn up with the idea that the Goblin would be able to defend bombers against hostile aircraft. At the time, the concept of a ‘parasite aircraft’ was still extremely novel and basic. However, the overall encompassing idea behind this kind of fighter was that it would be a component of a large carrier aircraft that could be held in flight and launched by the carrier in order to defend the primary mission (in this case, the Goblin could defend the B-36). Despite the promising concept, the performance of the XF-85 Goblin was determined to be inferior to many – if not all – of the fighter jets it would perhaps encounter. As a result, the egg-shaped prototype, with its’ fork-tailed design, was abandoned and instead, focus was shifted onto the concept of mid-air refuelling for existing and higher performance fighter aircraft.