C1 - Air conditionning and pressurization
C2 - Autopilot
C3 - Communication and navigation
C5 - Electricity and lighting
C6 - Development
C7 - APU motor (accessories)
C8 - Flight controls
C9 - Fuel
C10 - Rotor Helicopter (accessories)
C11 - Transmission Helicopter (accessories)
C12 - Hydraulic
C13 - Registration indication system
C14 - Landing gear
C18 - Frost / rain / fire protection
C20 - Structure