Roll out the Barrel. We'll have a barrel of fun! You know what? I like Aeroplane Jelly. And I like Bertie the aeroplane, too. and I like the Ford Flivver Both happy little planes with rotund fuselages. But they weren't the winners in the tubby stakes. Back in 1932 the Caproni factory in Italy built the epitome of barrel fuselage aircraft. The plane was the Stipa Caproni. Designed by Luigi Stipa (1900–1992) and built by Caproni, it was meant as a proof of concept experimental platform to test Stipa's idea to mount the engine and propeller inside a fuselage that itself formed a tapered duct, or venturi tube, and compressed the propeller's airflow and the engine exhaust before it exited the duct at the trailing edge of the aircraft, essentially applying Bernoulli's principle of fluid movements to make the aircraft's engine more efficient. Initial testing showed that the "intubed propeller" design did increase the engine's efficiency as Stipa had calculated, and the additional lift provided by the airfoil shape of the interior of the duct itself allowed a very low landing speed of only 68 km/h (42 mph). Unfortunately, the "intubed propeller" design also induced so much aerodynamic drag that the benefits in engine efficiency were cancelled out, and the aircraft's top speed proved to be only 131 km/h (81 mph). Stipa himself never had intended his "intubed propeller" to be employed on single-engine aircraft like the Caproni-Stipa—which he viewed merely as a testbed. Can you see the Stipa Caproni anywhere? Well, not the original, but a couple of crazy Aussies built a 3/5 scale version in Queensland back in the late 90's. From the story told here http://www.seqair.com/Hangar/Zuccoli/Legends/Legends.html one might think that the idea to build one was the result of the four unknown quantities - XXXX
