23.1097—Carburetor deicing fluid system capacity.
        
        (i) 
         That required to provide fluid at the rate specified in  § 23.1095 for a time equal to three percent of the maximum endurance of the airplane; or
    
    
    
    
        
        (b) 
         If the available preheat exceeds 50 °F. but is less than 100 °F., the capacity of the system may be decreased in proportion to the heat rise available in excess of 50 °F.