What certificate should employees of CCCC Third Aviation Administration take?

Employees of CCCC Third Engineering Bureau need to obtain relevant professional qualification certificates, and the specific requirements depend on different positions. Through the inquiry of relevant materials, it shows that the employees of CCCC No.3 Navigation Bureau need to obtain relevant professional qualification certificates, and the specific requirements depend on different positions. For example, a crew member needs to obtain a crew certificate, and a mechanic needs to obtain a corresponding mechanic certificate.