VM R5-420, the real thing.
Our 4.45 m (175 in) wingspan Aichi A3D1 "Val" at the "Mega-Flugshow" Göttingen 2011. The 66,9 kg (147 lb) Val is made of balsa and plywood, except for the glassfibre engine cowling and wheel spats. Steel and aluminum are used for the wing spar joiner and landing gear. The full size World War II carrier-borne dive bomber of the Imperial Japanese Navy had 14,37 m (47 ft 2 in) wingspan and was powered by a 1075 hp radial, it cruised at 296 km/h (184 mph), the max. speed was only 390 km/h (242 mph). The model is available from Valach Motors in various stages of completion, from partly built up to ready for flight with radio and engine installed.
The power of the VM R5-420 is phenomenal, for take-off I open the throttle only about 1/3 to make it look realistic, for cruising speed about 1/4 is just right and then the sound of the engine is totally convincing. In this video it is different, because the two Mustangs of John and Ben Barnitz could not hold formation when I was flying with scale speed so I had to open the throttle. When watching please keep in mind that it was our first attempt to fly the Aichi and the Mustangs in formation, and also Philipp Dorow had used my camera for the first time. My special thanks to Philipp!
In the second video, you can watch the VM R5-420 running on the test bench. Why is Holger sitting on the test bench? The simple answer is that the VM R5-420 produces so much thrust, that despite it's heavy weight, the bench moved forward even with two pallets on top of the table for extra weight.
The effect of the prop wash on Holger's face was also for us a new experience...