Helicopter

From HeliNet

The flying machine itself.

According to the BMFA ^[1]

A helicopter is a heavier-than-air aeromodel which derives all of its lift and horizontal propulsion from a power-driven rotor system(s) rotating about a nominally vertical axis (or axes). Fixed horizontal supporting surfaces up to 4% of the swept of the lifting rotor(s) are permitted. A fixed or controllable horizontal stabiliser up to 2% of the swept area of the lifting rotor(s) is permitted. Ground effect machines (hovercraft), convertiplanes or aircraft which hover by means of propeller slipstream(s) deflected downward are not considered to be helicopters.

References

1. ↑ BMFA Rulebook