119.23—Operators engaged in passenger-carrying operations, cargo operations, or both with airplanes when common carriage is not involved.
        
        (a) 
         Each person who conducts operations when common carriage is not involved with airplanes having a passenger-seat configuration of 20 seats or more, excluding each crewmember seat, or a payload capacity of 6,000 pounds or more, shall, unless deviation authority is issued—
    
    
        
        (1) 
         Comply with the certification and operations specifications requirements of  part 125 of this chapter ;
    
    
        
        (2) 
         Conduct its operations with those airplanes in accordance with the requirements of  part 125 of this chapter; and
    
    
    
        
        (b) 
         Each person who conducts noncommon carriage (except as provided in  § 91.501(b) of this chapter) or private carriage operations for compensation or hire with airplanes having a passenger-seat configuration of less than 20 seats, excluding each crewmember seat, and a payload capacity of less than 6,000 pounds shall—
    
    
        
        (1) 
         Comply with the certification and operations specifications requirements in subpart C of this part;
    
    
        
        (2) 
         Conduct those operations in accordance with the requirements of  part 135 of this chapter, except for those requirements applicable only to commuter operations; and