The tables predict the maximum altitude for a particular rocket and
motor class to ensure that a rocket will remain under the waivered altitude
and/or cloud deck.
The tables do NOT predict the altitude for a specific rocket and motor.
The tables will work for "typical" rockets. The tables may not apply
to rockets with a very low coefficient of drag (Cd) such as rockets with
boattails.
Find the matching motor class and airframe diameter. Rocket weight is
with the motor.
Example:
A rocket with a 25% I motor will have a lower apogee than the same rocket
with a 50% I motor, but the table for a 50% I will provide a maximum altitude
that the rocket should not exceed with either a 25% or 50% I motor.
-
5,000' Waivered Altitude
-
Clouds at 4,000'
-
4" Diameter, 4 pound rocket
-
Aerotech I195 motor - 426 Newton-seconds total impulse (33% I)
Use the 50% I table. According to the table the rocket will go less than
2900' and can be flown provided other factors are safe (thrust-to-weight
ratio).
1/4 pound = 4 ounces
1/2 pound = 8 ounces
3/4 pound = 12 ounces
Use at your own risk. Dean Roth, the creator of the tables, assumes
no liability for use of this data, and recommends that RSOs require a flight
simulator for large rockets, large motors and minimum diameter rockets. |