Yep, these are the old Aeroworks Katanas. I have one (see avatar). World Models was the manufacturer for Aeroworks.
These planes fly great, but they tend to come out tailheavy, as well as heavy overall. The wings and heavy aluminum landing gear contribute to most of this weight. For the price though, it is a 3D monster.
Mine has a BME 110 in it. Yes, I had to add the weight back to get it to balance, and yes, its still tail heavy
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Doug