1/2A Engine Helicopter Duration

32.1 Helicopter Duration Competition comprises nine events open to any single-staged model rocket which uses the principle of autorotation as the sole means of recovery. The purpose of this competition is to achieve the longest flight duration using an autorotating recovery system.

32.2 Each entry must be decelerated during descent by its autorotating recovery device. The resulting autorotation must be around the vertical axis. A model that descends nose first, or flips over once during descent is permitted. A model that flips over more than once shall be disqualified.

32.3 Recovery devices employing flexible (e.g. plastic film or cloth) surfaces are prohibited. Entries using a recovery system which is designed to act (or which actually acts) in a manner similar to a parachute, a rigid inverted bowl, or similar techniques are specifically excluded from this competition.

32.4 This competition is divided into classes based on the permissible total impulse of the motor(s). The following classes of Helicopter Duration Competition are established: