First Modern Russian Airboats (see the full-scale images by clicking on icons. Every image is 800x600, approx. 100 kB)
Some years ago a guy from here visited Canada. When coming back he brought a video tape showing a device which we've heard about earlier but nobody knew much about it. Since we're involved in homebuilt aviation we were curious about this boat using the prop. After brief investigation it was found that this boat could be very useful for our lakes and rivers which are covered with ice and snow for some months. Snowmobile and waterbike are good for their seasons but we still had 3-4 months per year when these mobiles aren't useful. The airboat should cover this lack.
Anyway it took 3 years to find time to try to build one. Oh, sorry, two :) We built two similar hulls which were powered with Subaru engines. One was 115 hp EJ-18 and another was 145 hp EJ-20. Both have gear box reduction excellently made in Russia. We use these conversions for our autogyros.
It took 4 months only to build both airboats.
Since we're slightly familiar with composites using to build light aircraft so we built the hull of composite which saved us a lot of empty weight: the 4.5 meter length ship weights approx. 450 kg (1000 lbs) only, all included. To make it more safe in cold waters we filled the hull with foam bricks packed in polyethylene for better safety and long life. Thus we can be sure that it floats even being torpedoed by rocks etc. The bottom is flat and it is reinforced with UHMV.
First runs showed that the main goal is achieved though we still have to look for some improvements. They are mostly: the correct engine pitch, more agility (I believe we should add more rudders square and to put them in more proper place). I'd also like to play with engine moving it slightly forward and back for better CG position.
As you can see the craft has a cockpit/roof which may be easily released for summer season though it is good thing for long-range travels - you can use it for sleeping and/or as luggage compartment.
The boat runs fine carrying 4 adults at 50-55 kmh at 75% power. I wonder what would be it's speed on snow and ice :) Anyway it was a fun to build these crafts and we're now thinking of making a small business around that.
I'd be glad to hear any comments/suggestions which can be e-mailed here.
Have a nice day!
Yours faithfully,
Alex