Helicopter Duration rules

« Duration Events

32.1 Scope

Helicopter Duration Competition comprises eleven events open to any single-staged model rocket that 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 Autorotation

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 during descent is permitted.

32.3 Recovery

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

32.4 Classes

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:

Motor Class Weighting Factor Multi-Round Maximum
1/8A 21 20 sec
1/4A 20 30 sec
1/2A 19 60 sec
A 20 120 sec
FAI A 20 180 sec
B 21 180 sec
C 22 240 sec
D 23 300 sec
E 24 300 sec
F 26 300 sec
G 27 300 sec