Cluster Altitude is comprised of six events open to single-stage model rockets.
The purpose of the event is to achieve the highest altitude.
23.3 Retained Motors
All motor cases are to be retained in the entry. Following an official flight, a contestant must present his/her entry as recovered to a contest official for verification of motor casing retention or the flight must be disqualified.
Air starts are prohibited.
23.5 Partial Ignition
Partial cluster ignition must be deemed an official flight unless disqualified for other safety reasons by the RSO.
The following five classes of Cluster Altitude are established:
1/8A x 2 Motor
1/4A x 2 Motor
1/2A x 3 Motor
A x 4 Motor
B x 5 Motor
C x 6 Motor