Precision Duration rules
Precision Duration Competition comprises three events open to any single-staged model rocket. The purpose of this competition is to accurately predict the duration that a model will achieve.
The three classes of Precision Duration are:
39.2.1 Predicted Duration
The contestant must predict the duration in seconds that the model will achieve. This Predicted Duration shall be recorded on the flight card and given to the Contest Director or his/her deputy prior to any official flight by the contestant at the meet. The minimum duration prediction allowable is 30 seconds.
Weighting Factor 8
39.2.2 Set Duration
The Contest Director shall set the target duration when the meet is sanctioned. This value shall appear on the sanction form and all appropriate contest information. The target duration shall be a multiple of 5 seconds between 30 and 120 seconds. All contestants shall attempt to achieve this same Set Duration.
Weighting Factor 8
39.2.3 Random Duration
The Contest Director shall randomly select the target duration just prior to when the event is flown, by draw, dice, or other random device. The target duration shall be a multiple of 5 seconds between 30 and 120 seconds. All contestants shall attempt to achieve this same Random Duration.
Weighting Factor 10
A contestant entered in Precision Duration Competition shall make his/her official flight in Precision Duration before flying any other event requiring timing.
39.4 Number of Flights
Entries shall be allowed only one official flight in Precision Duration Competition. In the case of a timer malfunction, any flight allowed under Rule 15.11 shall be made by the same model, and no changes in configuration, motor type, or prediction shall be allowed.
The entry may not be radio controlled. The entry shall not contain a dethermalizer or other device whose purpose is to cause the model to land after a predetermined amount of elapsed time. No human intervention (e.g., catching the model) shall be allowed between launch and touchdown. If the model is not allowed to land naturally, the entry shall be disqualified. Any model that drifts out of sight of the timers while still in the sky shall earn only flight points.
Precision Duration Competition shall be scored as follows: the achieved duration of the model shall be divided by the target duration, and the result multiplied by 100. This figure shall then be rounded to the nearest 0.1%. If the result is greater than or equal to 100, subtract 100 from it; otherwise, subtract it from 100. The contestant whose score comes closest to zero shall be declared the winner.
39.7 Weighting Factor
The Weighting Factor for Precision Duration and Set Duration Competition is 8. The Weighting Factor for Random Duration is 10.
The model is not required to be returned to the officials, except as stated in Rule 9.10.