The CPA has no connection to SPA...
CPA follows the AMA Published 1980-81 rule book..
http://www.classicpatternassociation.../1980-1981.pdf
Most all the information can be found on the CPA website or on other RCU post about planes.
SPA has there set of rules for planes and engines etc ..here is there site
http://www.seniorpattern.com/
cpa#2