Data Sheet ACD/BAC/004 Data Sheet Download Resource The file you are trying to access requires you to be logged in as a registered user. Registration is free, sign up today. Username Enter your Curtiss-Wright Defense Solutions username. Password Enter the password that accompanies your username. Forgot password? Don’t have an account? Register here. The ACD/BAC/004 is an electroless nickel-plated, aluminum backshell for use with CON/KAD/003/CP mating connectors. ACD/BAC/004 The ACD/BAC/004, nickel-plated and electroless, is an aluminum backshell.