Retractable gear is by hand cranking- 3 turns per side and yes is a simple wire mechanism. For you guys in the states- it may be possible to build a part 103 version as the original with a Rotax 503 and lots of paint and retractable gear is 145 kg. If you could figure a way to make it 115kg or 254lb then you would be golden. Possibly using light tube for the wing? Worth a thought.