At all stages of development of trikes, various schemes and arrangements were encountered. They can be divided into two groups. The first group includes trikes, which take-off due to run-up the pilot. Advantages of the vehicles of this group are small weight of structure, possibility of installing low-powered engines on them and use of uneven grounds for taking-off. However, they are not suitable for the transportation of payloads, since during takeoff a pilot has to withstand great physical exertion. In addition, it decreases the safety of flights because a pilot of such apparatus is not fixed rigidly relative to the structure, but is in a soft suspension system that allows pendulum travel relative to the wing.
The analysis of aviation accidents on hang gliders (trikes of the first group) shows that the overwhelming majority of severe injuries occur when the head or chest strikes the ground. When stalling, which is possible during flights at low altitudes and low speeds, the trike may collide with the ground when its trajectory is steeply inclined; in such a situation the pilot's body is tilted forward, which increases the possibility of unpleasant consequences. The most common are trikes of the second group, having a chassis, in many respects repeating the fuselage of the micro plane and including a power frame, the seat of pilots, etc. (in common speech - a "trolley"). Power plant (engine with an air screw, fuel tank, etc.) is mounted on the chassis. Motorized carriage (suspension system) is attached to the wing through a joint, which has at least two degrees of freedom in angular motion. Power plant, pilot's seat, chassis, equipment and other elements are fixed on the motorized carriage. Motor-hang-gliders with the trolley are easy to operate, they do not have any special design difficulties, which allow you to quickly disassemble and assemble them, replace the wing. Such trikes are more comfortable, but are controlled in the same way as sports hang gliders. Motorcycle is also adapted for the transportation of goods and passengers. With the wing removed, this trike can serve as a land vehicle.