As of June 2 of 2013, Tsheten Dorji's original backpack helicopter took the form of a "Helo-Hang Glider" with two-stroke motorcycle engine driving two-blade main and tail rotor systems with wooden blades. As the name suggests, it was essentially an ultralight helicopter, but with the pilot hanging from a harness under the frame like a hang-glider. Then, in June 8, it became a "Gyro-Hang Glider", which retained the same general layout, except in an ultralight autogyro form with an engine and tractor propeller directly in front of the pilot.
After being faced with an engine availability issue yet again in June 18, he instead chose to pursue the design as an engineless towed gyro-glider, after being inspired by successful test-flight footage of Russian engineer V.V. Shumeyko's gyro-glider of the same principle in 1989. A test model with wooden blades has been built (pictured), but has not been successfully tested yet.
Images © Tsheten Dorji (tsheten8), 2013